Myth of the Month

A 67-year-old man with stage 3 chronic kidney disease (CKD) develops abdominal pain over 24 hours. He has had low grade fevers and nausea. He has a history of colon cancer and had a resection four years ago. Abdominal exam reveals tenderness to palpation, including rebound tenderness in his right lower quadrant. Labs: hemoglobin: 13; hematocrit: 39; white blood cells: 18,000; platelets: 333; blood urea nitrogen: 28; creatinine: 1.8 (estimated glomerular filtration rate: 37); sodium: 136; potassium: 3.9; bicarbonate: 24; chlorine: 105; and lipase: 10.

What testing would you recommend?

A) Ultrasound

B) Non contrast computed tomography (CT)

C) Contrast CT

D) MRI without gadolinium

The correct answer here is to get a contrast CT scan, as it will give you the most appropriate diagnostic information.

For years, we have hesitated to order contrast studies in our patients with CKD, for fear of causing contrast-induced nephrotoxicity. We might choose less helpful studies that avoid contrast, or might not obtain imaging that is needed. Over the years I have especially seen this in the case of avoiding computed tomography angiography (CTA) for evaluation of pulmonary embolus and choosing the much less useful ventilation/perfusion scan. The problem arises with the fact that patients with CKD are more likely to develop worsening renal function when they get sick.

The assumption had been that when kidney injury occurred after contrast that it was due to the contrast. Many recent studies refute this assumption. Lee and colleagues performed an analysis of six retrospective studies involving a total of 55,963 participants. They found that patients with CKD receiving contrast material did not have an increased risk of deteriorating renal function compared with those without CKD (odds ratio, 1.07; 95% confidence interval, 0.98-1.17).¹

The early studies reporting contrast-induced renal disease were in patients who received high osmolality contrast agents.² Most patients now receive low osmolality agents, with less nephrotoxicity.³
 

Key points of guidelines

This year, the American College of Radiology and the National Kidney Foundation put out joint guidelines that helped clarify why there is a diminished concern for contrast-induced kidney disease in the modern era.⁴ Below are some of the key points of these guidelines:

• The risk of contrast-induced acute kidney injury (AKI) from intravenous iodinated contrast media is lower than previously thought.
• Necessary contrast material–enhanced CT without a suitable alternative should not be avoided solely on the basis of contrast-induced chronic kidney insufficiency risk.
• Contrast-induced AKI risk should be determined primarily by using CKD stage and AKI.
• Patients at high risk for contrast-induced kidney injury include those with recent AKI and those with estimated glomerular filtration rate (eGFR) less than 30 mL/min per 1.73 m².

Data supporting guidelines

The data from several studies used to support these recommendations were impressive, showing just how low the risk for contrast-induced AKI is in most patients. In these studies, the risk of contrast-induced AKI has been estimated to be near 0% for patients with an eGFR greater than or equal to 45 and 0%-2% for patients with an eGFR of 30-44.^5-7 This information and recommendations make imaging much easier. In most of our patients, we can get contrast studies when we need them. The group to be concerned about are patients with eGFRs less than 30. The guidelines single out this group as the patients where risk/benefit needs to be calculated before proceeding with the study, and to use prophylactic saline hydration in patients not undergoing dialysis.

Myth: Contrast-induced renal disease is common.
 

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact him at [email protected].

References

1. Lee YC et al. Contrast-induced acute kidney injury among patients with chronic kidney disease undergoing imaging studies: A meta-analysis. Am J Roentgenol. 2019 Oct;213(4):728-35.

2. Luk L et al. Intravenous contrast-induced nephropathy: The rise and fall of a threatening idea. Adv Chronic Kidney Dis. 2017 May;24(3):169-75.

3. Goldfarb S et al. Low-osmolality contrast media and the risk of contrast-associated nephrotoxicity. Invest Radiol. 1993;28(Suppl 5):7-10.

4. Davenport MS, et al. Use of intravenous iodinated contrast media in patients with kidney disease: Consensus statements from the American College of Radiology and the National Kidney Foundation. Kidney Med. 2020 Jan 22;2(1):85-93.

5. Davenport MS et al. Contrast material–induced nephrotoxicity and intravenous low-osmolality iodinated contrast material. Radiology. 2013;267(1):94-105.

6. McDonald RJ et al. Intravenous contrast material–induced nephropathy: Causal or coincident phenomenon? Radiology. 2013;267(1):106-18.

7. McDonald JS et al. Risk of intravenous contrast material–mediated acute kidney injury: A propensity scorematched study stratified by baseline-estimated glomerular filtration rate. Radiology. 2014;271(1):65-73.

A 67-year-old man with stage 3 chronic kidney disease (CKD) develops abdominal pain over 24 hours. He has had low grade fevers and nausea. He has a history of colon cancer and had a resection four years ago. Abdominal exam reveals tenderness to palpation, including rebound tenderness in his right lower quadrant. Labs: hemoglobin: 13; hematocrit: 39; white blood cells: 18,000; platelets: 333; blood urea nitrogen: 28; creatinine: 1.8 (estimated glomerular filtration rate: 37); sodium: 136; potassium: 3.9; bicarbonate: 24; chlorine: 105; and lipase: 10.

What testing would you recommend?

A) Ultrasound

B) Non contrast computed tomography (CT)

C) Contrast CT

D) MRI without gadolinium

The correct answer here is to get a contrast CT scan, as it will give you the most appropriate diagnostic information.

For years, we have hesitated to order contrast studies in our patients with CKD, for fear of causing contrast-induced nephrotoxicity. We might choose less helpful studies that avoid contrast, or might not obtain imaging that is needed. Over the years I have especially seen this in the case of avoiding computed tomography angiography (CTA) for evaluation of pulmonary embolus and choosing the much less useful ventilation/perfusion scan. The problem arises with the fact that patients with CKD are more likely to develop worsening renal function when they get sick.

The assumption had been that when kidney injury occurred after contrast that it was due to the contrast. Many recent studies refute this assumption. Lee and colleagues performed an analysis of six retrospective studies involving a total of 55,963 participants. They found that patients with CKD receiving contrast material did not have an increased risk of deteriorating renal function compared with those without CKD (odds ratio, 1.07; 95% confidence interval, 0.98-1.17).¹

The early studies reporting contrast-induced renal disease were in patients who received high osmolality contrast agents.² Most patients now receive low osmolality agents, with less nephrotoxicity.³
 

Key points of guidelines

This year, the American College of Radiology and the National Kidney Foundation put out joint guidelines that helped clarify why there is a diminished concern for contrast-induced kidney disease in the modern era.⁴ Below are some of the key points of these guidelines:

• The risk of contrast-induced acute kidney injury (AKI) from intravenous iodinated contrast media is lower than previously thought.
• Necessary contrast material–enhanced CT without a suitable alternative should not be avoided solely on the basis of contrast-induced chronic kidney insufficiency risk.
• Contrast-induced AKI risk should be determined primarily by using CKD stage and AKI.
• Patients at high risk for contrast-induced kidney injury include those with recent AKI and those with estimated glomerular filtration rate (eGFR) less than 30 mL/min per 1.73 m².

Data supporting guidelines

The data from several studies used to support these recommendations were impressive, showing just how low the risk for contrast-induced AKI is in most patients. In these studies, the risk of contrast-induced AKI has been estimated to be near 0% for patients with an eGFR greater than or equal to 45 and 0%-2% for patients with an eGFR of 30-44.^5-7 This information and recommendations make imaging much easier. In most of our patients, we can get contrast studies when we need them. The group to be concerned about are patients with eGFRs less than 30. The guidelines single out this group as the patients where risk/benefit needs to be calculated before proceeding with the study, and to use prophylactic saline hydration in patients not undergoing dialysis.

Myth: Contrast-induced renal disease is common.
 

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact him at [email protected].

References

1. Lee YC et al. Contrast-induced acute kidney injury among patients with chronic kidney disease undergoing imaging studies: A meta-analysis. Am J Roentgenol. 2019 Oct;213(4):728-35.

2. Luk L et al. Intravenous contrast-induced nephropathy: The rise and fall of a threatening idea. Adv Chronic Kidney Dis. 2017 May;24(3):169-75.

3. Goldfarb S et al. Low-osmolality contrast media and the risk of contrast-associated nephrotoxicity. Invest Radiol. 1993;28(Suppl 5):7-10.

4. Davenport MS, et al. Use of intravenous iodinated contrast media in patients with kidney disease: Consensus statements from the American College of Radiology and the National Kidney Foundation. Kidney Med. 2020 Jan 22;2(1):85-93.

5. Davenport MS et al. Contrast material–induced nephrotoxicity and intravenous low-osmolality iodinated contrast material. Radiology. 2013;267(1):94-105.

6. McDonald RJ et al. Intravenous contrast material–induced nephropathy: Causal or coincident phenomenon? Radiology. 2013;267(1):106-18.

7. McDonald JS et al. Risk of intravenous contrast material–mediated acute kidney injury: A propensity scorematched study stratified by baseline-estimated glomerular filtration rate. Radiology. 2014;271(1):65-73.

A 67-year-old man with stage 3 chronic kidney disease (CKD) develops abdominal pain over 24 hours. He has had low grade fevers and nausea. He has a history of colon cancer and had a resection four years ago. Abdominal exam reveals tenderness to palpation, including rebound tenderness in his right lower quadrant. Labs: hemoglobin: 13; hematocrit: 39; white blood cells: 18,000; platelets: 333; blood urea nitrogen: 28; creatinine: 1.8 (estimated glomerular filtration rate: 37); sodium: 136; potassium: 3.9; bicarbonate: 24; chlorine: 105; and lipase: 10.

What testing would you recommend?

A) Ultrasound

B) Non contrast computed tomography (CT)

C) Contrast CT

D) MRI without gadolinium

The correct answer here is to get a contrast CT scan, as it will give you the most appropriate diagnostic information.

For years, we have hesitated to order contrast studies in our patients with CKD, for fear of causing contrast-induced nephrotoxicity. We might choose less helpful studies that avoid contrast, or might not obtain imaging that is needed. Over the years I have especially seen this in the case of avoiding computed tomography angiography (CTA) for evaluation of pulmonary embolus and choosing the much less useful ventilation/perfusion scan. The problem arises with the fact that patients with CKD are more likely to develop worsening renal function when they get sick.

The assumption had been that when kidney injury occurred after contrast that it was due to the contrast. Many recent studies refute this assumption. Lee and colleagues performed an analysis of six retrospective studies involving a total of 55,963 participants. They found that patients with CKD receiving contrast material did not have an increased risk of deteriorating renal function compared with those without CKD (odds ratio, 1.07; 95% confidence interval, 0.98-1.17).¹

The early studies reporting contrast-induced renal disease were in patients who received high osmolality contrast agents.² Most patients now receive low osmolality agents, with less nephrotoxicity.³
 

Key points of guidelines

This year, the American College of Radiology and the National Kidney Foundation put out joint guidelines that helped clarify why there is a diminished concern for contrast-induced kidney disease in the modern era.⁴ Below are some of the key points of these guidelines:

• The risk of contrast-induced acute kidney injury (AKI) from intravenous iodinated contrast media is lower than previously thought.
• Necessary contrast material–enhanced CT without a suitable alternative should not be avoided solely on the basis of contrast-induced chronic kidney insufficiency risk.
• Contrast-induced AKI risk should be determined primarily by using CKD stage and AKI.
• Patients at high risk for contrast-induced kidney injury include those with recent AKI and those with estimated glomerular filtration rate (eGFR) less than 30 mL/min per 1.73 m².

Data supporting guidelines

The data from several studies used to support these recommendations were impressive, showing just how low the risk for contrast-induced AKI is in most patients. In these studies, the risk of contrast-induced AKI has been estimated to be near 0% for patients with an eGFR greater than or equal to 45 and 0%-2% for patients with an eGFR of 30-44.^5-7 This information and recommendations make imaging much easier. In most of our patients, we can get contrast studies when we need them. The group to be concerned about are patients with eGFRs less than 30. The guidelines single out this group as the patients where risk/benefit needs to be calculated before proceeding with the study, and to use prophylactic saline hydration in patients not undergoing dialysis.

Myth: Contrast-induced renal disease is common.
 

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact him at [email protected].

References

1. Lee YC et al. Contrast-induced acute kidney injury among patients with chronic kidney disease undergoing imaging studies: A meta-analysis. Am J Roentgenol. 2019 Oct;213(4):728-35.

2. Luk L et al. Intravenous contrast-induced nephropathy: The rise and fall of a threatening idea. Adv Chronic Kidney Dis. 2017 May;24(3):169-75.

3. Goldfarb S et al. Low-osmolality contrast media and the risk of contrast-associated nephrotoxicity. Invest Radiol. 1993;28(Suppl 5):7-10.

4. Davenport MS, et al. Use of intravenous iodinated contrast media in patients with kidney disease: Consensus statements from the American College of Radiology and the National Kidney Foundation. Kidney Med. 2020 Jan 22;2(1):85-93.

5. Davenport MS et al. Contrast material–induced nephrotoxicity and intravenous low-osmolality iodinated contrast material. Radiology. 2013;267(1):94-105.

6. McDonald RJ et al. Intravenous contrast material–induced nephropathy: Causal or coincident phenomenon? Radiology. 2013;267(1):106-18.

7. McDonald JS et al. Risk of intravenous contrast material–mediated acute kidney injury: A propensity scorematched study stratified by baseline-estimated glomerular filtration rate. Radiology. 2014;271(1):65-73.

A 46-year-old man who lives in Tacoma, Wash., is seen for fatigue. He has a no significant past medical history. He is not taking any medications. His physical exam is unremarkable. His hemoglobin is 12 gm/dL, hematocrit is 37 gm/dL, mean corpuscular volume (MCV) is 103 fL, and thyroid-stimulating hormone level is 1.2 mU/L.

What workup do you recommend?

A) B₁₂, folate testing

B) Alcohol history, B₁₂, folate testing

C) Alcohol history, B₁₂ testing

I would choose doing a careful alcohol history and vitamin B₁₂ testing.

Dr. Seppä and colleagues looked at all outpatients who had a blood count done over an 8-month period.¹ A total of 9,527 blood counts were ordered, and 287 (3%) had macrocytosis.¹ Further workup was done for 113 of the patients. The most common cause found for macrocytosis was alcohol abuse, in 74 (65%) of the patients (80% of the men and 36% of the women). In several studies, vitamin B₁₂ deficiency was the cause of macrocytosis in 5%-7% of patients.^2,3

In 1978, a study by Davidson and Hamilton looked at 200 consecutive patients with MCVs over 100, and were able to find a cause in 80%.⁴ Sixteen of these patients had a low B₁₂ level and 10 had a low folate level.

In recent years, folate has become an extremely unlikely cause of macrocytic anemias. In 1998, the Food and Drug Administration required folic acid fortification of enriched grain products in the United States to help decrease the risk of neural tube defects. Similar fortification efforts were undertaken in Canada. Since 1998, anemia due to folate deficiency has essentially disappeared in individuals who have access to fortified grain products.

Joelson and colleagues looked at data on folate testing from the year prior to fortification of the grain supply (1997) and after (2004).⁵ They found that, in 1997, 4.8% of tests had a folate level less than 160 ng/mL compared with only 0.6% of tests in 2004.

When a more stringent cutoff for deficiency was used (94 ng/mL) 0.98% of tests were below that level in 1997, and 0.09% in 2004. The mean RBC folate level in 1997 was 420 ng/mL and rose to 697 ng/mL in 2004. Of the patients who did have low folate levels, only a minority had elevated MCVs.

Shojania et al. looked at folate testing in Canada after widespread fortification had started.⁶ They found that 0.5% of 2,154 serum folate levels were low and 0.7% of 560 red blood cell folate levels were low. Folate deficiency was not the cause of anemia in any of the patients with low folate levels.

Theisen-Toupal and colleagues did a retrospective study looking at folate testing over an 11-year period after fortification.⁷ The researchers examined the results of 84,187 assessments of folate levels. Forty-seven (0.056%) of the tests found patients with folate deficiency, 166 (0.197%), found patients with low-normal folate levels, 57,411 (68.195%) of tests yielded normal results, and 26,563 (31.552%) of tests found high folate levels. The opinion of the authors was that folate testing should be severely reduced or eliminated. Furthermore, the American Society for Clinical Pathology, as part of the Choosing Wisely campaign, states: “Do not order red blood cell folate levels at all.”⁸

So what does this all mean? We have been taught to have a reflex response to the evaluation of macrocytosis to test for B₁₂ and folate. Neither of these are particularly common causes of macrocytosis, and in countries where there is grain fortification, folate deficiency is exceedingly uncommon, and should not be tested for early in any diagnostic process.
 

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact him at [email protected].

References

1. Seppä K et al. Evaluation of macrocytosis by general practitioners. J Stud Alcohol. 1996 Jan;57(1):97-100.

2. Seppä K et al. Blood count and hematologic morphology in nonanemic macrocytosis: Differences between alcohol abuse and pernicious anemia. Alcohol. 1993 Sep-Oct;10(5):343-7.

3. Wymer A, Becker DM. Recognition and evaluation of red blood cell macrocytosis in the primary care setting. J Gen Intern Med. 1990 May-Jun;5(3):192-7.

4. Davidson RJ, Hamilton PJ. High mean red cell volume: Its incidence and significance in routine haematology. J Clin Pathol. 1978 May;31[5]:493-8.

5. Joelson DW, Fiebig EW. Diminished need for folate measurements among indigent populations in the post folic acid supplementation era. Arch Pathol Lab Med. 2007 Mar;131(3):477-80.

6. Shojania AM, von Kuster K. Ordering folate assays is no longer justified for investigation of anemias, in folic acid fortified countries. BMC Res Notes. 2010 Jan 25;3:22. doi: 10.1186/1756-0500-3-22.

7. Theisen-Toupal et al. Low yield of outpatient serum folate testing. JAMA Intern Med. 2014 Oct. doi: 10.1001/jamainternmed.2014.3593.

8. Choosing Wisely: American Society for Clinical Pathology, Oct. 19, 2017. Recommendation.

A 46-year-old man who lives in Tacoma, Wash., is seen for fatigue. He has a no significant past medical history. He is not taking any medications. His physical exam is unremarkable. His hemoglobin is 12 gm/dL, hematocrit is 37 gm/dL, mean corpuscular volume (MCV) is 103 fL, and thyroid-stimulating hormone level is 1.2 mU/L.

What workup do you recommend?

A) B₁₂, folate testing

B) Alcohol history, B₁₂, folate testing

C) Alcohol history, B₁₂ testing

I would choose doing a careful alcohol history and vitamin B₁₂ testing.

Dr. Seppä and colleagues looked at all outpatients who had a blood count done over an 8-month period.¹ A total of 9,527 blood counts were ordered, and 287 (3%) had macrocytosis.¹ Further workup was done for 113 of the patients. The most common cause found for macrocytosis was alcohol abuse, in 74 (65%) of the patients (80% of the men and 36% of the women). In several studies, vitamin B₁₂ deficiency was the cause of macrocytosis in 5%-7% of patients.^2,3

In 1978, a study by Davidson and Hamilton looked at 200 consecutive patients with MCVs over 100, and were able to find a cause in 80%.⁴ Sixteen of these patients had a low B₁₂ level and 10 had a low folate level.

In recent years, folate has become an extremely unlikely cause of macrocytic anemias. In 1998, the Food and Drug Administration required folic acid fortification of enriched grain products in the United States to help decrease the risk of neural tube defects. Similar fortification efforts were undertaken in Canada. Since 1998, anemia due to folate deficiency has essentially disappeared in individuals who have access to fortified grain products.

Joelson and colleagues looked at data on folate testing from the year prior to fortification of the grain supply (1997) and after (2004).⁵ They found that, in 1997, 4.8% of tests had a folate level less than 160 ng/mL compared with only 0.6% of tests in 2004.

When a more stringent cutoff for deficiency was used (94 ng/mL) 0.98% of tests were below that level in 1997, and 0.09% in 2004. The mean RBC folate level in 1997 was 420 ng/mL and rose to 697 ng/mL in 2004. Of the patients who did have low folate levels, only a minority had elevated MCVs.

Shojania et al. looked at folate testing in Canada after widespread fortification had started.⁶ They found that 0.5% of 2,154 serum folate levels were low and 0.7% of 560 red blood cell folate levels were low. Folate deficiency was not the cause of anemia in any of the patients with low folate levels.

Theisen-Toupal and colleagues did a retrospective study looking at folate testing over an 11-year period after fortification.⁷ The researchers examined the results of 84,187 assessments of folate levels. Forty-seven (0.056%) of the tests found patients with folate deficiency, 166 (0.197%), found patients with low-normal folate levels, 57,411 (68.195%) of tests yielded normal results, and 26,563 (31.552%) of tests found high folate levels. The opinion of the authors was that folate testing should be severely reduced or eliminated. Furthermore, the American Society for Clinical Pathology, as part of the Choosing Wisely campaign, states: “Do not order red blood cell folate levels at all.”⁸

So what does this all mean? We have been taught to have a reflex response to the evaluation of macrocytosis to test for B₁₂ and folate. Neither of these are particularly common causes of macrocytosis, and in countries where there is grain fortification, folate deficiency is exceedingly uncommon, and should not be tested for early in any diagnostic process.
 

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact him at [email protected].

References

1. Seppä K et al. Evaluation of macrocytosis by general practitioners. J Stud Alcohol. 1996 Jan;57(1):97-100.

2. Seppä K et al. Blood count and hematologic morphology in nonanemic macrocytosis: Differences between alcohol abuse and pernicious anemia. Alcohol. 1993 Sep-Oct;10(5):343-7.

3. Wymer A, Becker DM. Recognition and evaluation of red blood cell macrocytosis in the primary care setting. J Gen Intern Med. 1990 May-Jun;5(3):192-7.

4. Davidson RJ, Hamilton PJ. High mean red cell volume: Its incidence and significance in routine haematology. J Clin Pathol. 1978 May;31[5]:493-8.

5. Joelson DW, Fiebig EW. Diminished need for folate measurements among indigent populations in the post folic acid supplementation era. Arch Pathol Lab Med. 2007 Mar;131(3):477-80.

6. Shojania AM, von Kuster K. Ordering folate assays is no longer justified for investigation of anemias, in folic acid fortified countries. BMC Res Notes. 2010 Jan 25;3:22. doi: 10.1186/1756-0500-3-22.

7. Theisen-Toupal et al. Low yield of outpatient serum folate testing. JAMA Intern Med. 2014 Oct. doi: 10.1001/jamainternmed.2014.3593.

8. Choosing Wisely: American Society for Clinical Pathology, Oct. 19, 2017. Recommendation.

A 46-year-old man who lives in Tacoma, Wash., is seen for fatigue. He has a no significant past medical history. He is not taking any medications. His physical exam is unremarkable. His hemoglobin is 12 gm/dL, hematocrit is 37 gm/dL, mean corpuscular volume (MCV) is 103 fL, and thyroid-stimulating hormone level is 1.2 mU/L.

What workup do you recommend?

A) B₁₂, folate testing

B) Alcohol history, B₁₂, folate testing

C) Alcohol history, B₁₂ testing

I would choose doing a careful alcohol history and vitamin B₁₂ testing.

Dr. Seppä and colleagues looked at all outpatients who had a blood count done over an 8-month period.¹ A total of 9,527 blood counts were ordered, and 287 (3%) had macrocytosis.¹ Further workup was done for 113 of the patients. The most common cause found for macrocytosis was alcohol abuse, in 74 (65%) of the patients (80% of the men and 36% of the women). In several studies, vitamin B₁₂ deficiency was the cause of macrocytosis in 5%-7% of patients.^2,3

In 1978, a study by Davidson and Hamilton looked at 200 consecutive patients with MCVs over 100, and were able to find a cause in 80%.⁴ Sixteen of these patients had a low B₁₂ level and 10 had a low folate level.

In recent years, folate has become an extremely unlikely cause of macrocytic anemias. In 1998, the Food and Drug Administration required folic acid fortification of enriched grain products in the United States to help decrease the risk of neural tube defects. Similar fortification efforts were undertaken in Canada. Since 1998, anemia due to folate deficiency has essentially disappeared in individuals who have access to fortified grain products.

Joelson and colleagues looked at data on folate testing from the year prior to fortification of the grain supply (1997) and after (2004).⁵ They found that, in 1997, 4.8% of tests had a folate level less than 160 ng/mL compared with only 0.6% of tests in 2004.

When a more stringent cutoff for deficiency was used (94 ng/mL) 0.98% of tests were below that level in 1997, and 0.09% in 2004. The mean RBC folate level in 1997 was 420 ng/mL and rose to 697 ng/mL in 2004. Of the patients who did have low folate levels, only a minority had elevated MCVs.

Shojania et al. looked at folate testing in Canada after widespread fortification had started.⁶ They found that 0.5% of 2,154 serum folate levels were low and 0.7% of 560 red blood cell folate levels were low. Folate deficiency was not the cause of anemia in any of the patients with low folate levels.

Theisen-Toupal and colleagues did a retrospective study looking at folate testing over an 11-year period after fortification.⁷ The researchers examined the results of 84,187 assessments of folate levels. Forty-seven (0.056%) of the tests found patients with folate deficiency, 166 (0.197%), found patients with low-normal folate levels, 57,411 (68.195%) of tests yielded normal results, and 26,563 (31.552%) of tests found high folate levels. The opinion of the authors was that folate testing should be severely reduced or eliminated. Furthermore, the American Society for Clinical Pathology, as part of the Choosing Wisely campaign, states: “Do not order red blood cell folate levels at all.”⁸

So what does this all mean? We have been taught to have a reflex response to the evaluation of macrocytosis to test for B₁₂ and folate. Neither of these are particularly common causes of macrocytosis, and in countries where there is grain fortification, folate deficiency is exceedingly uncommon, and should not be tested for early in any diagnostic process.
 

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact him at [email protected].

References

1. Seppä K et al. Evaluation of macrocytosis by general practitioners. J Stud Alcohol. 1996 Jan;57(1):97-100.

2. Seppä K et al. Blood count and hematologic morphology in nonanemic macrocytosis: Differences between alcohol abuse and pernicious anemia. Alcohol. 1993 Sep-Oct;10(5):343-7.

3. Wymer A, Becker DM. Recognition and evaluation of red blood cell macrocytosis in the primary care setting. J Gen Intern Med. 1990 May-Jun;5(3):192-7.

4. Davidson RJ, Hamilton PJ. High mean red cell volume: Its incidence and significance in routine haematology. J Clin Pathol. 1978 May;31[5]:493-8.

5. Joelson DW, Fiebig EW. Diminished need for folate measurements among indigent populations in the post folic acid supplementation era. Arch Pathol Lab Med. 2007 Mar;131(3):477-80.

6. Shojania AM, von Kuster K. Ordering folate assays is no longer justified for investigation of anemias, in folic acid fortified countries. BMC Res Notes. 2010 Jan 25;3:22. doi: 10.1186/1756-0500-3-22.

7. Theisen-Toupal et al. Low yield of outpatient serum folate testing. JAMA Intern Med. 2014 Oct. doi: 10.1001/jamainternmed.2014.3593.

8. Choosing Wisely: American Society for Clinical Pathology, Oct. 19, 2017. Recommendation.

This month, I would like to touch on a few COVID-19 topics that have received much publicity, with some messages about them having been confusing.

Let’s start with a case:

A 37-year-old woman is seen in clinic for a 5-day history of cough, fever, chest tightness, and onset of dyspnea on the day of her office visit.

An exam reveals her blood pressure is 100/60 mm Hg, her pulse is 100 beats per minute, her temperature is 38.7° C, her oxygen saturation is 93%, and her respiratory rate is 20 breaths per minute.

Auscultation of the chest revealed bilateral wheezing and rhonchi. A nasopharyngeal swab is sent for COVID-19 and is negative; she also tests negative for influenza.

Her hemoglobin level is 13 g/dL, hematocrit was 39%, platelet count was 155,000 per mcL of blood, and D-dimer level was 8.4 mcg/mL (normal is less than 0.4 mcg/mL.) Her white blood cell count was 6,000 per mcL of blood (neutrophils, 4,900; lymphocytes, 800; basophils, 200). Her chest x-ray showed bilateral lower lobe infiltrates.
 

What do you recommend?

A. Begin azithromycin plus ceftriaxone

B. Begin azithromycin

C. Begin oseltamivir

D. Obtain chest CT

E. Repeat COVID-19 test

With the massive amount of information coming out every day on COVID-19, it is hard to keep up with all of it, and sort out accurate, reviewed studies. We are in a position where we need to take in what we can and assess the best data available.

In the case above, I think choices D or E would make sense. This patient very likely has COVID-19 based on clinical symptoms and lab parameters. The negative COVID-19 test gives us pause, but several studies show that false negative tests are not uncommon.

Long et al. reported on 36 patients who had received both chest CT and real-time reverse transcription polymerase chain reaction (rRT-PCR) for COVID-19.¹ All were eventually diagnosed with COVID-19 pneumonia. The CT scan had a very high sensitivity (35/36) of 97.2%, whereas the rRT-PCR had a lower sensitivity (30/36) of 83%. All six of the patients with a negative COVID-19 test initially were positive on repeat testing (three on the second test, three on the third test).

There are concerns about what the sensitivity of the rRT-PCR tests being run in the United States are. At this point, I think that, when the pretest probability of COVID-19 infection is very high based on local epidemiology and clinical symptoms, a negative COVID rRT-PCR does not eliminate the diagnosis. In many cases, COVID-19 may still be the most likely diagnosis.

Early in the pandemic, the symptoms that were emphasized were fever, cough, and dyspnea. Those were all crucial symptoms for a disease that causes pneumonia. GI symptoms were initially deemphasized. In an early study released from Wuhan, China, only about 5% of COVID-19 patients had nausea or diarrhea.² In a study of 305 patients focused on gastrointestinal symptoms, half of the patients had diarrhea, half had anorexia and 30% had nausea.³ In a small series of nine patients who presented with only GI symptoms, four of these patients never developed fever or pulmonary symptoms.³

On March 14, the French health minister, Olivier Véran, tweeted that “taking anti-inflammatory drugs (ibuprofen, cortisone ...) could be an aggravating factor for the infection. If you have a fever, take paracetamol.” This was picked up by many news services, and soon became standard recommendations, despite no data.

There is reason for concern for NSAIDs, as regular NSAID use has been tied to more complications in patients with respiratory tract infections.⁴ I have never been a proponent of regular NSAID use in patients who are infected, because the likelihood of toxicity is elevated in patients who are volume depleted or under physiologic stress. But at this time, there is no evidence on problems with episodic NSAID use in patients with COVID-19.

Another widely disseminated decree was that patients with COVID-19 should not use ACE inhibitors and angiotensin II receptor blockers (ARBs). COVID-19 binds to their target cells through ACE2, which is expressed by epithelial cells of the lung, intestine and kidney. Patients who are treated with ACE inhibitors and ARBs have been shown to have more ACE2 expression.

In a letter to the editor by Fang et al. published in Lancet Respiratory Medicine, the authors raised the question of whether patients might be better served to be switched from ACE inhibitors and ARBs to calcium-channel blockers for the treatment of hypertension.⁵ A small study by Meng et al. looked at outcomes of patients on these drugs who had COVID-19 infection.⁶ They looked at 417 patients admitted to a hospital in China with COVID-19 infection. A total of 42 patients were on medications for hypertension. Group 1 were patients on ACE inhibitors/ARBs (17 patients) and group 2 were patients on other antihypertensives (25 patients). During hospitalization 12 patients (48%) in group 2 were categorized as having severe disease and 1 patient died. In group 1 (the ACE inhibitor/ARB–treated patients) only four (23%) were categorized as having severe disease, and no patients in this group died.

Vaduganathan et al. published a special report in the New England Journal of Medicine strongly arguing the point that “[u]ntil further data are available, we think that [renin-angiotensin-aldosterone system] inhibitors should be continued in patients in otherwise stable condition who are at risk for, being evaluated for, or with COVID-19”.⁷ This position is supported by the American Heart Association, the American College of Cardiology, the American College of Physicians, and 11 other medical organizations.
 

Take-home messages

• Testing isn’t perfect – if you have strong suspicion for COVID-19 disease, retest.
• GI symptoms appear to be common, and rarely may be the only symptoms initially.
• NSAIDs are always risky in really sick patients, but data specific to COVID-19 is lacking.
• ACE inhibitors/ARBs should not be avoided in patients with COVID-19.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact Dr. Paauw at [email protected].

References

1. Long C et al. Diagnosis of the Coronavirus disease (COVID-19): rRT-PCR or CT? Eur J Radiol. 2020 Mar 25;126:108961.

2. Zhou F et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: A retrospective cohort study. Lancet. 2020 Mar 28;395(10229):1054-62.

3. Tian Y et al. Review article: Gastrointestinal features in COVID-19 and the possibility of faecal transmission. Aliment Pharmacol Ther. 2020;00:1–9.

4. Voiriot G et al. Risks related to the use of nonsteroidal anti-inflammatory drugs in community-acquired pneumonia in adult and pediatric patients. J Clin Med. 2019;8:E786.

5. Fang L et al. Are patients with hypertension and diabetes mellitus at increased risk for COVID-19 infection? Lancet Respir Med. 2020 Mar 11. doi:10.1016/S2213-2600(20)30116-8.

6. Meng J et al. Renin-angiotensin system inhibitors improve the clinical outcomes of COVID-19 patients with hypertension. Renin-angiotensin system inhibitors improve the clinical outcomes of COVID-19 patients with hypertension. Emerg Microbes Infect. 2020 Dec;9(1):757-60.

7. Vaduganathan M et al. Renin-angiotensin-aldosterone system inhibitors in patients with COVID-19. N Engl J Med. 2020 Mar 30. doi: 10.1056/NEJMsr2005760.

This month, I would like to touch on a few COVID-19 topics that have received much publicity, with some messages about them having been confusing.

Let’s start with a case:

A 37-year-old woman is seen in clinic for a 5-day history of cough, fever, chest tightness, and onset of dyspnea on the day of her office visit.

An exam reveals her blood pressure is 100/60 mm Hg, her pulse is 100 beats per minute, her temperature is 38.7° C, her oxygen saturation is 93%, and her respiratory rate is 20 breaths per minute.

Auscultation of the chest revealed bilateral wheezing and rhonchi. A nasopharyngeal swab is sent for COVID-19 and is negative; she also tests negative for influenza.

Her hemoglobin level is 13 g/dL, hematocrit was 39%, platelet count was 155,000 per mcL of blood, and D-dimer level was 8.4 mcg/mL (normal is less than 0.4 mcg/mL.) Her white blood cell count was 6,000 per mcL of blood (neutrophils, 4,900; lymphocytes, 800; basophils, 200). Her chest x-ray showed bilateral lower lobe infiltrates.
 

What do you recommend?

A. Begin azithromycin plus ceftriaxone

B. Begin azithromycin

C. Begin oseltamivir

D. Obtain chest CT

E. Repeat COVID-19 test

With the massive amount of information coming out every day on COVID-19, it is hard to keep up with all of it, and sort out accurate, reviewed studies. We are in a position where we need to take in what we can and assess the best data available.

In the case above, I think choices D or E would make sense. This patient very likely has COVID-19 based on clinical symptoms and lab parameters. The negative COVID-19 test gives us pause, but several studies show that false negative tests are not uncommon.

Long et al. reported on 36 patients who had received both chest CT and real-time reverse transcription polymerase chain reaction (rRT-PCR) for COVID-19.¹ All were eventually diagnosed with COVID-19 pneumonia. The CT scan had a very high sensitivity (35/36) of 97.2%, whereas the rRT-PCR had a lower sensitivity (30/36) of 83%. All six of the patients with a negative COVID-19 test initially were positive on repeat testing (three on the second test, three on the third test).

There are concerns about what the sensitivity of the rRT-PCR tests being run in the United States are. At this point, I think that, when the pretest probability of COVID-19 infection is very high based on local epidemiology and clinical symptoms, a negative COVID rRT-PCR does not eliminate the diagnosis. In many cases, COVID-19 may still be the most likely diagnosis.

Early in the pandemic, the symptoms that were emphasized were fever, cough, and dyspnea. Those were all crucial symptoms for a disease that causes pneumonia. GI symptoms were initially deemphasized. In an early study released from Wuhan, China, only about 5% of COVID-19 patients had nausea or diarrhea.² In a study of 305 patients focused on gastrointestinal symptoms, half of the patients had diarrhea, half had anorexia and 30% had nausea.³ In a small series of nine patients who presented with only GI symptoms, four of these patients never developed fever or pulmonary symptoms.³

On March 14, the French health minister, Olivier Véran, tweeted that “taking anti-inflammatory drugs (ibuprofen, cortisone ...) could be an aggravating factor for the infection. If you have a fever, take paracetamol.” This was picked up by many news services, and soon became standard recommendations, despite no data.

There is reason for concern for NSAIDs, as regular NSAID use has been tied to more complications in patients with respiratory tract infections.⁴ I have never been a proponent of regular NSAID use in patients who are infected, because the likelihood of toxicity is elevated in patients who are volume depleted or under physiologic stress. But at this time, there is no evidence on problems with episodic NSAID use in patients with COVID-19.

Another widely disseminated decree was that patients with COVID-19 should not use ACE inhibitors and angiotensin II receptor blockers (ARBs). COVID-19 binds to their target cells through ACE2, which is expressed by epithelial cells of the lung, intestine and kidney. Patients who are treated with ACE inhibitors and ARBs have been shown to have more ACE2 expression.

In a letter to the editor by Fang et al. published in Lancet Respiratory Medicine, the authors raised the question of whether patients might be better served to be switched from ACE inhibitors and ARBs to calcium-channel blockers for the treatment of hypertension.⁵ A small study by Meng et al. looked at outcomes of patients on these drugs who had COVID-19 infection.⁶ They looked at 417 patients admitted to a hospital in China with COVID-19 infection. A total of 42 patients were on medications for hypertension. Group 1 were patients on ACE inhibitors/ARBs (17 patients) and group 2 were patients on other antihypertensives (25 patients). During hospitalization 12 patients (48%) in group 2 were categorized as having severe disease and 1 patient died. In group 1 (the ACE inhibitor/ARB–treated patients) only four (23%) were categorized as having severe disease, and no patients in this group died.

Vaduganathan et al. published a special report in the New England Journal of Medicine strongly arguing the point that “[u]ntil further data are available, we think that [renin-angiotensin-aldosterone system] inhibitors should be continued in patients in otherwise stable condition who are at risk for, being evaluated for, or with COVID-19”.⁷ This position is supported by the American Heart Association, the American College of Cardiology, the American College of Physicians, and 11 other medical organizations.
 

Take-home messages

• Testing isn’t perfect – if you have strong suspicion for COVID-19 disease, retest.
• GI symptoms appear to be common, and rarely may be the only symptoms initially.
• NSAIDs are always risky in really sick patients, but data specific to COVID-19 is lacking.
• ACE inhibitors/ARBs should not be avoided in patients with COVID-19.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact Dr. Paauw at [email protected].

References

1. Long C et al. Diagnosis of the Coronavirus disease (COVID-19): rRT-PCR or CT? Eur J Radiol. 2020 Mar 25;126:108961.

2. Zhou F et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: A retrospective cohort study. Lancet. 2020 Mar 28;395(10229):1054-62.

3. Tian Y et al. Review article: Gastrointestinal features in COVID-19 and the possibility of faecal transmission. Aliment Pharmacol Ther. 2020;00:1–9.

4. Voiriot G et al. Risks related to the use of nonsteroidal anti-inflammatory drugs in community-acquired pneumonia in adult and pediatric patients. J Clin Med. 2019;8:E786.

5. Fang L et al. Are patients with hypertension and diabetes mellitus at increased risk for COVID-19 infection? Lancet Respir Med. 2020 Mar 11. doi:10.1016/S2213-2600(20)30116-8.

6. Meng J et al. Renin-angiotensin system inhibitors improve the clinical outcomes of COVID-19 patients with hypertension. Renin-angiotensin system inhibitors improve the clinical outcomes of COVID-19 patients with hypertension. Emerg Microbes Infect. 2020 Dec;9(1):757-60.

7. Vaduganathan M et al. Renin-angiotensin-aldosterone system inhibitors in patients with COVID-19. N Engl J Med. 2020 Mar 30. doi: 10.1056/NEJMsr2005760.

This month, I would like to touch on a few COVID-19 topics that have received much publicity, with some messages about them having been confusing.

Let’s start with a case:

A 37-year-old woman is seen in clinic for a 5-day history of cough, fever, chest tightness, and onset of dyspnea on the day of her office visit.

An exam reveals her blood pressure is 100/60 mm Hg, her pulse is 100 beats per minute, her temperature is 38.7° C, her oxygen saturation is 93%, and her respiratory rate is 20 breaths per minute.

Auscultation of the chest revealed bilateral wheezing and rhonchi. A nasopharyngeal swab is sent for COVID-19 and is negative; she also tests negative for influenza.

Her hemoglobin level is 13 g/dL, hematocrit was 39%, platelet count was 155,000 per mcL of blood, and D-dimer level was 8.4 mcg/mL (normal is less than 0.4 mcg/mL.) Her white blood cell count was 6,000 per mcL of blood (neutrophils, 4,900; lymphocytes, 800; basophils, 200). Her chest x-ray showed bilateral lower lobe infiltrates.
 

What do you recommend?

A. Begin azithromycin plus ceftriaxone

B. Begin azithromycin

C. Begin oseltamivir

D. Obtain chest CT

E. Repeat COVID-19 test

With the massive amount of information coming out every day on COVID-19, it is hard to keep up with all of it, and sort out accurate, reviewed studies. We are in a position where we need to take in what we can and assess the best data available.

In the case above, I think choices D or E would make sense. This patient very likely has COVID-19 based on clinical symptoms and lab parameters. The negative COVID-19 test gives us pause, but several studies show that false negative tests are not uncommon.

Long et al. reported on 36 patients who had received both chest CT and real-time reverse transcription polymerase chain reaction (rRT-PCR) for COVID-19.¹ All were eventually diagnosed with COVID-19 pneumonia. The CT scan had a very high sensitivity (35/36) of 97.2%, whereas the rRT-PCR had a lower sensitivity (30/36) of 83%. All six of the patients with a negative COVID-19 test initially were positive on repeat testing (three on the second test, three on the third test).

There are concerns about what the sensitivity of the rRT-PCR tests being run in the United States are. At this point, I think that, when the pretest probability of COVID-19 infection is very high based on local epidemiology and clinical symptoms, a negative COVID rRT-PCR does not eliminate the diagnosis. In many cases, COVID-19 may still be the most likely diagnosis.

Early in the pandemic, the symptoms that were emphasized were fever, cough, and dyspnea. Those were all crucial symptoms for a disease that causes pneumonia. GI symptoms were initially deemphasized. In an early study released from Wuhan, China, only about 5% of COVID-19 patients had nausea or diarrhea.² In a study of 305 patients focused on gastrointestinal symptoms, half of the patients had diarrhea, half had anorexia and 30% had nausea.³ In a small series of nine patients who presented with only GI symptoms, four of these patients never developed fever or pulmonary symptoms.³

On March 14, the French health minister, Olivier Véran, tweeted that “taking anti-inflammatory drugs (ibuprofen, cortisone ...) could be an aggravating factor for the infection. If you have a fever, take paracetamol.” This was picked up by many news services, and soon became standard recommendations, despite no data.

There is reason for concern for NSAIDs, as regular NSAID use has been tied to more complications in patients with respiratory tract infections.⁴ I have never been a proponent of regular NSAID use in patients who are infected, because the likelihood of toxicity is elevated in patients who are volume depleted or under physiologic stress. But at this time, there is no evidence on problems with episodic NSAID use in patients with COVID-19.

Another widely disseminated decree was that patients with COVID-19 should not use ACE inhibitors and angiotensin II receptor blockers (ARBs). COVID-19 binds to their target cells through ACE2, which is expressed by epithelial cells of the lung, intestine and kidney. Patients who are treated with ACE inhibitors and ARBs have been shown to have more ACE2 expression.

In a letter to the editor by Fang et al. published in Lancet Respiratory Medicine, the authors raised the question of whether patients might be better served to be switched from ACE inhibitors and ARBs to calcium-channel blockers for the treatment of hypertension.⁵ A small study by Meng et al. looked at outcomes of patients on these drugs who had COVID-19 infection.⁶ They looked at 417 patients admitted to a hospital in China with COVID-19 infection. A total of 42 patients were on medications for hypertension. Group 1 were patients on ACE inhibitors/ARBs (17 patients) and group 2 were patients on other antihypertensives (25 patients). During hospitalization 12 patients (48%) in group 2 were categorized as having severe disease and 1 patient died. In group 1 (the ACE inhibitor/ARB–treated patients) only four (23%) were categorized as having severe disease, and no patients in this group died.

Vaduganathan et al. published a special report in the New England Journal of Medicine strongly arguing the point that “[u]ntil further data are available, we think that [renin-angiotensin-aldosterone system] inhibitors should be continued in patients in otherwise stable condition who are at risk for, being evaluated for, or with COVID-19”.⁷ This position is supported by the American Heart Association, the American College of Cardiology, the American College of Physicians, and 11 other medical organizations.
 

Take-home messages

• Testing isn’t perfect – if you have strong suspicion for COVID-19 disease, retest.
• GI symptoms appear to be common, and rarely may be the only symptoms initially.
• NSAIDs are always risky in really sick patients, but data specific to COVID-19 is lacking.
• ACE inhibitors/ARBs should not be avoided in patients with COVID-19.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact Dr. Paauw at [email protected].

References

1. Long C et al. Diagnosis of the Coronavirus disease (COVID-19): rRT-PCR or CT? Eur J Radiol. 2020 Mar 25;126:108961.

2. Zhou F et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: A retrospective cohort study. Lancet. 2020 Mar 28;395(10229):1054-62.

3. Tian Y et al. Review article: Gastrointestinal features in COVID-19 and the possibility of faecal transmission. Aliment Pharmacol Ther. 2020;00:1–9.

4. Voiriot G et al. Risks related to the use of nonsteroidal anti-inflammatory drugs in community-acquired pneumonia in adult and pediatric patients. J Clin Med. 2019;8:E786.

5. Fang L et al. Are patients with hypertension and diabetes mellitus at increased risk for COVID-19 infection? Lancet Respir Med. 2020 Mar 11. doi:10.1016/S2213-2600(20)30116-8.

6. Meng J et al. Renin-angiotensin system inhibitors improve the clinical outcomes of COVID-19 patients with hypertension. Renin-angiotensin system inhibitors improve the clinical outcomes of COVID-19 patients with hypertension. Emerg Microbes Infect. 2020 Dec;9(1):757-60.

7. Vaduganathan M et al. Renin-angiotensin-aldosterone system inhibitors in patients with COVID-19. N Engl J Med. 2020 Mar 30. doi: 10.1056/NEJMsr2005760.

A 59-year-old man is admitted with abdominal pain. He has a history of pancreatitis. A contrast CT scan is ordered. He reports a history of severe shellfish allergy when the radiology tech checks him in for the procedure. You are paged regarding what to do:

A) Continue with scan as ordered.

B) Switch to MRI scan.

C) Switch to MRI scan with gadolinium.

D) Continue with CT with contrast, give dose of Solu-Medrol.

E) Continue with CT with contrast give IV diphenhydramine.
 

The correct answer here is A, This patient can receive his scan and receive contrast as ordered.

For many years, patients have been asked about shellfish allergy as a proxy for having increased risk when receiving iodine containing contrast. The mistaken thought was that shellfish contains iodine, so allergy to shellfish was likely to portend allergy to iodine.

Allergy to shellfish is caused by individual proteins that are definitely not in iodine-containing contrast.¹ Beaty et al. studied the prevalence of the belief that allergy to shellfish is tied to iodine allergy in a survey given to 231 faculty radiologists and interventional cardiologists.² Almost 70% responded that they inquire about seafood allergy before procedures that require iodine contrast, and 37% reported they would withhold the contrast or premedicate patients if they had a seafood allergy.

In a more recent study, Westermann-Clark and colleagues surveyed 252 health professionals before and after an educational intervention to dispel the myth of shellfish allergy and iodinated contrast reactions.³ Before the intervention, 66% of participants felt it was important to ask about shellfish allergies and 93% felt it was important to ask about iodine allergies; 26% responded that they would withhold iodinated contrast material in patients with a shellfish allergy, and 56% would withhold in patients with an iodine allergy. A total of 62% reported they would premedicate patients with a shellfish allergy and 75% would premedicate patients with an iodine allergy. The numbers declined dramatically after the educational intervention.

Patients who have seafood allergy have a higher rate of reactions to iodinated contrast, but not at a higher rate than do patients with other food allergies or asthma.⁴ Most radiology departments do not screen for other food allergies despite the fact these allergies have the same increased risk as for patients with a seafood/shellfish allergy. These patients are more allergic, and in general, are more likely to have reactions. The American Academy of Allergy, Asthma, and Immunology recommends not routinely ordering low- or iso-osmolar radiocontrast media or pretreating with either antihistamines or steroids in patients with a history of seafood allergy.⁵

• It is unnecessary and unhelpful to ask patients about seafood allergies before ordering radiologic studies involving contrast.
• Iodine allergy does not exist.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

References

1. Narayan AK et al. Avoiding contrast-enhanced computed tomography scans in patients with shellfish allergies. J Hosp Med. 2016 Jun;11(6):435-7.

2. Beaty AD et al. Seafood allergy and radiocontrast media: Are physicians propagating a myth? Am J Med. 2008 Feb;121(2):158.e1-4.

3. Westermann-Clark E et al. Debunking myths about “allergy” to radiocontrast media in an academic institution. Postgrad Med. 2015 Apr;127(3):295-300.

4. Coakley FV and DM Panicek. Iodine allergy: An oyster without a pearl? AJR Am J Roentgenol. 1997 Oct;169(4):951-2.

5. American Academy of Allergy, Asthma & Immunology recommendations on low- or iso-osmolar radiocontrast media.

6. Schabelman E and M Witting. The relationship of radiocontrast, iodine, and seafood allergies: A medical myth exposed. J Emerg Med. 2010 Nov;39(5):701-7.

7. van Ketel WG and WH van den Berg. Sensitization to povidone-iodine. Dermatol Clin. 1990 Jan;8(1):107-9.

A 59-year-old man is admitted with abdominal pain. He has a history of pancreatitis. A contrast CT scan is ordered. He reports a history of severe shellfish allergy when the radiology tech checks him in for the procedure. You are paged regarding what to do:

A) Continue with scan as ordered.

B) Switch to MRI scan.

C) Switch to MRI scan with gadolinium.

D) Continue with CT with contrast, give dose of Solu-Medrol.

E) Continue with CT with contrast give IV diphenhydramine.
 

The correct answer here is A, This patient can receive his scan and receive contrast as ordered.

For many years, patients have been asked about shellfish allergy as a proxy for having increased risk when receiving iodine containing contrast. The mistaken thought was that shellfish contains iodine, so allergy to shellfish was likely to portend allergy to iodine.

Allergy to shellfish is caused by individual proteins that are definitely not in iodine-containing contrast.¹ Beaty et al. studied the prevalence of the belief that allergy to shellfish is tied to iodine allergy in a survey given to 231 faculty radiologists and interventional cardiologists.² Almost 70% responded that they inquire about seafood allergy before procedures that require iodine contrast, and 37% reported they would withhold the contrast or premedicate patients if they had a seafood allergy.

In a more recent study, Westermann-Clark and colleagues surveyed 252 health professionals before and after an educational intervention to dispel the myth of shellfish allergy and iodinated contrast reactions.³ Before the intervention, 66% of participants felt it was important to ask about shellfish allergies and 93% felt it was important to ask about iodine allergies; 26% responded that they would withhold iodinated contrast material in patients with a shellfish allergy, and 56% would withhold in patients with an iodine allergy. A total of 62% reported they would premedicate patients with a shellfish allergy and 75% would premedicate patients with an iodine allergy. The numbers declined dramatically after the educational intervention.

Patients who have seafood allergy have a higher rate of reactions to iodinated contrast, but not at a higher rate than do patients with other food allergies or asthma.⁴ Most radiology departments do not screen for other food allergies despite the fact these allergies have the same increased risk as for patients with a seafood/shellfish allergy. These patients are more allergic, and in general, are more likely to have reactions. The American Academy of Allergy, Asthma, and Immunology recommends not routinely ordering low- or iso-osmolar radiocontrast media or pretreating with either antihistamines or steroids in patients with a history of seafood allergy.⁵

• It is unnecessary and unhelpful to ask patients about seafood allergies before ordering radiologic studies involving contrast.
• Iodine allergy does not exist.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

References

1. Narayan AK et al. Avoiding contrast-enhanced computed tomography scans in patients with shellfish allergies. J Hosp Med. 2016 Jun;11(6):435-7.

2. Beaty AD et al. Seafood allergy and radiocontrast media: Are physicians propagating a myth? Am J Med. 2008 Feb;121(2):158.e1-4.

3. Westermann-Clark E et al. Debunking myths about “allergy” to radiocontrast media in an academic institution. Postgrad Med. 2015 Apr;127(3):295-300.

4. Coakley FV and DM Panicek. Iodine allergy: An oyster without a pearl? AJR Am J Roentgenol. 1997 Oct;169(4):951-2.

5. American Academy of Allergy, Asthma & Immunology recommendations on low- or iso-osmolar radiocontrast media.

6. Schabelman E and M Witting. The relationship of radiocontrast, iodine, and seafood allergies: A medical myth exposed. J Emerg Med. 2010 Nov;39(5):701-7.

7. van Ketel WG and WH van den Berg. Sensitization to povidone-iodine. Dermatol Clin. 1990 Jan;8(1):107-9.

A 59-year-old man is admitted with abdominal pain. He has a history of pancreatitis. A contrast CT scan is ordered. He reports a history of severe shellfish allergy when the radiology tech checks him in for the procedure. You are paged regarding what to do:

A) Continue with scan as ordered.

B) Switch to MRI scan.

C) Switch to MRI scan with gadolinium.

D) Continue with CT with contrast, give dose of Solu-Medrol.

E) Continue with CT with contrast give IV diphenhydramine.
 

The correct answer here is A, This patient can receive his scan and receive contrast as ordered.

For many years, patients have been asked about shellfish allergy as a proxy for having increased risk when receiving iodine containing contrast. The mistaken thought was that shellfish contains iodine, so allergy to shellfish was likely to portend allergy to iodine.

Allergy to shellfish is caused by individual proteins that are definitely not in iodine-containing contrast.¹ Beaty et al. studied the prevalence of the belief that allergy to shellfish is tied to iodine allergy in a survey given to 231 faculty radiologists and interventional cardiologists.² Almost 70% responded that they inquire about seafood allergy before procedures that require iodine contrast, and 37% reported they would withhold the contrast or premedicate patients if they had a seafood allergy.

In a more recent study, Westermann-Clark and colleagues surveyed 252 health professionals before and after an educational intervention to dispel the myth of shellfish allergy and iodinated contrast reactions.³ Before the intervention, 66% of participants felt it was important to ask about shellfish allergies and 93% felt it was important to ask about iodine allergies; 26% responded that they would withhold iodinated contrast material in patients with a shellfish allergy, and 56% would withhold in patients with an iodine allergy. A total of 62% reported they would premedicate patients with a shellfish allergy and 75% would premedicate patients with an iodine allergy. The numbers declined dramatically after the educational intervention.

Patients who have seafood allergy have a higher rate of reactions to iodinated contrast, but not at a higher rate than do patients with other food allergies or asthma.⁴ Most radiology departments do not screen for other food allergies despite the fact these allergies have the same increased risk as for patients with a seafood/shellfish allergy. These patients are more allergic, and in general, are more likely to have reactions. The American Academy of Allergy, Asthma, and Immunology recommends not routinely ordering low- or iso-osmolar radiocontrast media or pretreating with either antihistamines or steroids in patients with a history of seafood allergy.⁵

• It is unnecessary and unhelpful to ask patients about seafood allergies before ordering radiologic studies involving contrast.
• Iodine allergy does not exist.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

References

1. Narayan AK et al. Avoiding contrast-enhanced computed tomography scans in patients with shellfish allergies. J Hosp Med. 2016 Jun;11(6):435-7.

2. Beaty AD et al. Seafood allergy and radiocontrast media: Are physicians propagating a myth? Am J Med. 2008 Feb;121(2):158.e1-4.

3. Westermann-Clark E et al. Debunking myths about “allergy” to radiocontrast media in an academic institution. Postgrad Med. 2015 Apr;127(3):295-300.

4. Coakley FV and DM Panicek. Iodine allergy: An oyster without a pearl? AJR Am J Roentgenol. 1997 Oct;169(4):951-2.

5. American Academy of Allergy, Asthma & Immunology recommendations on low- or iso-osmolar radiocontrast media.

6. Schabelman E and M Witting. The relationship of radiocontrast, iodine, and seafood allergies: A medical myth exposed. J Emerg Med. 2010 Nov;39(5):701-7.

7. van Ketel WG and WH van den Berg. Sensitization to povidone-iodine. Dermatol Clin. 1990 Jan;8(1):107-9.

A 40-year-old man presents with severe right flank pain for 1 hour. He has had this in the past when he passed a kidney stone. Urinalysis shows greater than 100 red blood cells per high power field (HPF). CT shows a 6-mm stone in the left ureter.

What do you recommend for therapy?

A. IV ketorolac and IV fluids.

B. IV morphine and IV fluids.

C. IV morphine.

D. IV ketorolac.

This is a common scenario, especially in emergency department settings and acute care clinics. Patients arrive in severe pain because of renal colic from kidney stones. Standard teaching that I received many years ago was that this patient should receive IV fluid to “help float the stone out” and narcotic pain medications to treat the severe pain the patient was in.

Is there good evidence that this is the best therapy?

There are scant data on the practice of IV fluid for treatment of renal stone passage. W. Patrick Springhart, MD, and his colleagues studied 43 patients who presented to the ED for treatment of renal colic.¹ All patients had CT evaluation for stones and received intravenous analgesia. Twenty patients were randomized to receive 2 L of normal saline over 2 hours, and 23 patients received minimal IV saline (20 mL/hour). There were no differences between the two groups in pain scores, narcotic requirements, or stone passage rates.

In an older study, Tom-Harald Edna, PhD, and colleagues studied 60 patients with ureteral colic, randomizing them to receive either no fluid or 3 L of IV fluid over 6 hours.² There was no significant difference in pain between treatment groups.

A Cochrane analysis in 2012 concluded that there was no reliable evidence to support the use of high-volume fluid therapy in the treatment of acute ureteral colic.³

Standard treatment of pain for renal colic has been to use narcotics. In a randomized, double-blind trial comparing ketorolac and meperidine, William Cordell, MD, and his colleagues found that pain relief was superior in ketorolac-treated patients. Seventy-five percent of ketorolac patients had a 50% reduction in pain scores versus only 23% of the patients who received meperidine (P less than .001).⁴

Anna Holdgate and Tamara Pollock reviewed 20 studies that evaluated NSAIDs and narcotics for acute renal colic. They concluded that patients treated with NSAIDs had greater pain relief with less vomiting than did patients treated with narcotics.⁵

In the past decade, tamsulosin has been frequently used in patients with renal stones to possibly help with pain and promote more rapid stone passage. A recent randomized, controlled trial with 512 patients, authored by Andrew Meltzer, MD, and his colleagues, showed no improvement in stone passage rate in patients taking tamsulosin, compared with the rate seen with placebo.⁶

Previously published meta-analyses of multiple studies have shown a benefit to the use of alpha-blockers. Thijs Campschroer and colleagues included 67 studies that altogether included 10,509 participants.⁷ They found that the use of alpha-blockers led to possibly shorter stone expulsion times (3.4 days), less NSAID use, and fewer hospitalizations, with the evidence graded as low to moderate quality. Stone size seems to matter because use of alpha-blockers does not seem to make a difference for stones larger than 5 mm.

I think IV ketorolac would be the best of the options presented here for this patient. If a patient can safely take NSAIDs, those are probably the best option. There does not appear to be any reason to bolus hydrate patients with acute renal colic.

Dr. Paauw is a professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

References

1. J Endourol. 2006 Oct;20(10):713-6.

2. Scand J Urol Nephrol. 1983;17(2):175-8.

3. Cochrane Database Syst Rev. 2012 Feb 15;(2):CD004926.

4. Ann Emerg Med. 1996 Aug;28(2):151-8.

5. BMJ. 2004 Jun 12;328(7453):1401.

6. JAMA Intern Med. 2018 Aug 1;178(8):1051-7.

7. Cochrane Database Syst Rev. 2018 Apr 5;4:CD008509.

A 40-year-old man presents with severe right flank pain for 1 hour. He has had this in the past when he passed a kidney stone. Urinalysis shows greater than 100 red blood cells per high power field (HPF). CT shows a 6-mm stone in the left ureter.

What do you recommend for therapy?

A. IV ketorolac and IV fluids.

B. IV morphine and IV fluids.

C. IV morphine.

D. IV ketorolac.

This is a common scenario, especially in emergency department settings and acute care clinics. Patients arrive in severe pain because of renal colic from kidney stones. Standard teaching that I received many years ago was that this patient should receive IV fluid to “help float the stone out” and narcotic pain medications to treat the severe pain the patient was in.

Is there good evidence that this is the best therapy?

There are scant data on the practice of IV fluid for treatment of renal stone passage. W. Patrick Springhart, MD, and his colleagues studied 43 patients who presented to the ED for treatment of renal colic.¹ All patients had CT evaluation for stones and received intravenous analgesia. Twenty patients were randomized to receive 2 L of normal saline over 2 hours, and 23 patients received minimal IV saline (20 mL/hour). There were no differences between the two groups in pain scores, narcotic requirements, or stone passage rates.

In an older study, Tom-Harald Edna, PhD, and colleagues studied 60 patients with ureteral colic, randomizing them to receive either no fluid or 3 L of IV fluid over 6 hours.² There was no significant difference in pain between treatment groups.

A Cochrane analysis in 2012 concluded that there was no reliable evidence to support the use of high-volume fluid therapy in the treatment of acute ureteral colic.³

Standard treatment of pain for renal colic has been to use narcotics. In a randomized, double-blind trial comparing ketorolac and meperidine, William Cordell, MD, and his colleagues found that pain relief was superior in ketorolac-treated patients. Seventy-five percent of ketorolac patients had a 50% reduction in pain scores versus only 23% of the patients who received meperidine (P less than .001).⁴

Anna Holdgate and Tamara Pollock reviewed 20 studies that evaluated NSAIDs and narcotics for acute renal colic. They concluded that patients treated with NSAIDs had greater pain relief with less vomiting than did patients treated with narcotics.⁵

In the past decade, tamsulosin has been frequently used in patients with renal stones to possibly help with pain and promote more rapid stone passage. A recent randomized, controlled trial with 512 patients, authored by Andrew Meltzer, MD, and his colleagues, showed no improvement in stone passage rate in patients taking tamsulosin, compared with the rate seen with placebo.⁶

Previously published meta-analyses of multiple studies have shown a benefit to the use of alpha-blockers. Thijs Campschroer and colleagues included 67 studies that altogether included 10,509 participants.⁷ They found that the use of alpha-blockers led to possibly shorter stone expulsion times (3.4 days), less NSAID use, and fewer hospitalizations, with the evidence graded as low to moderate quality. Stone size seems to matter because use of alpha-blockers does not seem to make a difference for stones larger than 5 mm.

I think IV ketorolac would be the best of the options presented here for this patient. If a patient can safely take NSAIDs, those are probably the best option. There does not appear to be any reason to bolus hydrate patients with acute renal colic.

Dr. Paauw is a professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

References

1. J Endourol. 2006 Oct;20(10):713-6.

2. Scand J Urol Nephrol. 1983;17(2):175-8.

3. Cochrane Database Syst Rev. 2012 Feb 15;(2):CD004926.

4. Ann Emerg Med. 1996 Aug;28(2):151-8.

5. BMJ. 2004 Jun 12;328(7453):1401.

6. JAMA Intern Med. 2018 Aug 1;178(8):1051-7.

7. Cochrane Database Syst Rev. 2018 Apr 5;4:CD008509.

A 40-year-old man presents with severe right flank pain for 1 hour. He has had this in the past when he passed a kidney stone. Urinalysis shows greater than 100 red blood cells per high power field (HPF). CT shows a 6-mm stone in the left ureter.

What do you recommend for therapy?

A. IV ketorolac and IV fluids.

B. IV morphine and IV fluids.

C. IV morphine.

D. IV ketorolac.

This is a common scenario, especially in emergency department settings and acute care clinics. Patients arrive in severe pain because of renal colic from kidney stones. Standard teaching that I received many years ago was that this patient should receive IV fluid to “help float the stone out” and narcotic pain medications to treat the severe pain the patient was in.

Is there good evidence that this is the best therapy?

There are scant data on the practice of IV fluid for treatment of renal stone passage. W. Patrick Springhart, MD, and his colleagues studied 43 patients who presented to the ED for treatment of renal colic.¹ All patients had CT evaluation for stones and received intravenous analgesia. Twenty patients were randomized to receive 2 L of normal saline over 2 hours, and 23 patients received minimal IV saline (20 mL/hour). There were no differences between the two groups in pain scores, narcotic requirements, or stone passage rates.

In an older study, Tom-Harald Edna, PhD, and colleagues studied 60 patients with ureteral colic, randomizing them to receive either no fluid or 3 L of IV fluid over 6 hours.² There was no significant difference in pain between treatment groups.

A Cochrane analysis in 2012 concluded that there was no reliable evidence to support the use of high-volume fluid therapy in the treatment of acute ureteral colic.³

Standard treatment of pain for renal colic has been to use narcotics. In a randomized, double-blind trial comparing ketorolac and meperidine, William Cordell, MD, and his colleagues found that pain relief was superior in ketorolac-treated patients. Seventy-five percent of ketorolac patients had a 50% reduction in pain scores versus only 23% of the patients who received meperidine (P less than .001).⁴

Anna Holdgate and Tamara Pollock reviewed 20 studies that evaluated NSAIDs and narcotics for acute renal colic. They concluded that patients treated with NSAIDs had greater pain relief with less vomiting than did patients treated with narcotics.⁵

In the past decade, tamsulosin has been frequently used in patients with renal stones to possibly help with pain and promote more rapid stone passage. A recent randomized, controlled trial with 512 patients, authored by Andrew Meltzer, MD, and his colleagues, showed no improvement in stone passage rate in patients taking tamsulosin, compared with the rate seen with placebo.⁶

Previously published meta-analyses of multiple studies have shown a benefit to the use of alpha-blockers. Thijs Campschroer and colleagues included 67 studies that altogether included 10,509 participants.⁷ They found that the use of alpha-blockers led to possibly shorter stone expulsion times (3.4 days), less NSAID use, and fewer hospitalizations, with the evidence graded as low to moderate quality. Stone size seems to matter because use of alpha-blockers does not seem to make a difference for stones larger than 5 mm.

I think IV ketorolac would be the best of the options presented here for this patient. If a patient can safely take NSAIDs, those are probably the best option. There does not appear to be any reason to bolus hydrate patients with acute renal colic.

Dr. Paauw is a professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

References

1. J Endourol. 2006 Oct;20(10):713-6.

2. Scand J Urol Nephrol. 1983;17(2):175-8.

3. Cochrane Database Syst Rev. 2012 Feb 15;(2):CD004926.

4. Ann Emerg Med. 1996 Aug;28(2):151-8.

5. BMJ. 2004 Jun 12;328(7453):1401.

6. JAMA Intern Med. 2018 Aug 1;178(8):1051-7.

7. Cochrane Database Syst Rev. 2018 Apr 5;4:CD008509.

A 66-year-old man presents with substernal chest pressure and dyspnea that has been present for 45 minutes. He has nausea. Vital signs: blood pressure, 110/60; pulse, 100; oxygen saturation, 92%. Neck: elevated jugular venous pressure. Chest: clear. Cardiac: normal S1 S2, no murmurs. ECG: ST elevation in 2, 3, and aVF leads.

Which of these treatments do you recommend?

A. Morphine, oxygen, nitroglycerin, and aspirin (ASA).

B. Oxygen, morphine, ASA.

C. ASA.

In this patient, I think the correct approach would be to just give aspirin. Nitroglycerin would be problematic, as it appears that this patient might be having a right ventricular infarct, and lowering right-sided filling pressures with nitroglycerin may lead to severe hypotension.

There is controversy over the safety of routine morphine use for patients with chest pain.

Trip J. Meine, MD, and colleagues found that use of morphine either alone or in combination with nitroglycerin for patients presenting with non–ST-elevation acute coronary syndrome (NSTE-ACS) was associated with higher mortality.¹ Cian P. McCarthy, MD, and colleagues found the same results, with morphine use associated with larger infarct size, a longer hospital stay, and a trend toward increased mortality in invasively managed NSTE-ACS patients.² Suzanne de Waha and colleagues found that morphine use in patients with ST-segment elevation MIs had larger infarct size and less reperfusion success, as measured by cardiac MRI.³

Not all recent studies show a detrimental effect of morphine. Etienne Puymirat et al. reviewed in-hospital complications (death, nonfatal re-MI, stroke, stent thrombosis, and bleeding) and 1-year survival according to prehospital morphine use in 2,438 ST-elevation MI (STEMI) patients from the French Registry of Acute ST-elevation and non–ST-elevation Myocardial Infarction (FAST-MI).⁴ They found no increase in in-hospital complications or 1-year mortality.

The practice of using supplemental oxygen to treat all patients with MI became standard nearly a century ago, after oxygen was found in 1900 to relieve angina, and led to clinical improvement in four MI patients in a 1930 case series.^5,6

It was not studied in a controlled trial until 1976, when J.M. Rawles, MD, and colleagues randomized 157 patients with MI to 24 hours of oxygen at 8 L/min or to ambient air. They found no difference in mortality between the groups, but they did find a higher burden of MI in the intervention arm receiving supplemental oxygen, as measured by mean serum aspartate aminotransferase levels.⁷

The topic was not addressed again in a significant randomized trial until this century. Most notably, two recent studies again demonstrated no benefit of supplemental oxygen in normoxemic patients with MI.

In the AVOID trial in 2015, Dion Stub, MD, PhD, and colleagues randomized 441 patients with STEMI to oxygen at 8 L/min – from diagnosis in an ambulance until after cardiac catheterization – or to ambient air. They found no difference in death at 6 months, but did find an increased rate of in-hospital recurrent MIs, with 0.9% of the control group and 5.5% of the oxygen intervention arm suffering recurrence (P = .006).⁸ They also showed a larger area of myocardial infarct in the oxygen group, as measured by peak creatine kinase levels and cardiac MRI at 6 months.

Proposed mechanisms of increased myocardial injury from hyperoxia include increased coronary vascular resistance resulting in decreased myocardial perfusion, and increased reperfusion injury from formation of free radicals.⁹

Dr. Tubbesing is a senior resident in medicine at the University of Washington, Seattle. Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

References

1. Am Heart J. 2005 Jun;149(6):1043-9.

2. J Interv Cardiol. 2017 Nov 22. doi: 10.1111/joic.12464.

3. Clin Res Cardiol. 2015 Sep;104(9):727-34.

4. Eur Heart J. 2016 Apr 1;37(13):1063-71.

5. BMJ. 1900 Dec 1;2(2083):1568.

6. JAMA. 1930 May 3;94(18):1363-5.

7. Br Med J. 1976 May 8;1(6018):1121-3.

8. Circulation. 2015 Jun 16;131(24):2143-50.

9. Cochrane Database Syst Rev. 2016 Dec 19;12:CD007160.

10. N Engl J Med. 2017 Sep 28;377(13):1240-9.

A 66-year-old man presents with substernal chest pressure and dyspnea that has been present for 45 minutes. He has nausea. Vital signs: blood pressure, 110/60; pulse, 100; oxygen saturation, 92%. Neck: elevated jugular venous pressure. Chest: clear. Cardiac: normal S1 S2, no murmurs. ECG: ST elevation in 2, 3, and aVF leads.

Which of these treatments do you recommend?

A. Morphine, oxygen, nitroglycerin, and aspirin (ASA).

B. Oxygen, morphine, ASA.

C. ASA.

In this patient, I think the correct approach would be to just give aspirin. Nitroglycerin would be problematic, as it appears that this patient might be having a right ventricular infarct, and lowering right-sided filling pressures with nitroglycerin may lead to severe hypotension.

There is controversy over the safety of routine morphine use for patients with chest pain.

Trip J. Meine, MD, and colleagues found that use of morphine either alone or in combination with nitroglycerin for patients presenting with non–ST-elevation acute coronary syndrome (NSTE-ACS) was associated with higher mortality.¹ Cian P. McCarthy, MD, and colleagues found the same results, with morphine use associated with larger infarct size, a longer hospital stay, and a trend toward increased mortality in invasively managed NSTE-ACS patients.² Suzanne de Waha and colleagues found that morphine use in patients with ST-segment elevation MIs had larger infarct size and less reperfusion success, as measured by cardiac MRI.³

Not all recent studies show a detrimental effect of morphine. Etienne Puymirat et al. reviewed in-hospital complications (death, nonfatal re-MI, stroke, stent thrombosis, and bleeding) and 1-year survival according to prehospital morphine use in 2,438 ST-elevation MI (STEMI) patients from the French Registry of Acute ST-elevation and non–ST-elevation Myocardial Infarction (FAST-MI).⁴ They found no increase in in-hospital complications or 1-year mortality.

The practice of using supplemental oxygen to treat all patients with MI became standard nearly a century ago, after oxygen was found in 1900 to relieve angina, and led to clinical improvement in four MI patients in a 1930 case series.^5,6

It was not studied in a controlled trial until 1976, when J.M. Rawles, MD, and colleagues randomized 157 patients with MI to 24 hours of oxygen at 8 L/min or to ambient air. They found no difference in mortality between the groups, but they did find a higher burden of MI in the intervention arm receiving supplemental oxygen, as measured by mean serum aspartate aminotransferase levels.⁷

The topic was not addressed again in a significant randomized trial until this century. Most notably, two recent studies again demonstrated no benefit of supplemental oxygen in normoxemic patients with MI.

In the AVOID trial in 2015, Dion Stub, MD, PhD, and colleagues randomized 441 patients with STEMI to oxygen at 8 L/min – from diagnosis in an ambulance until after cardiac catheterization – or to ambient air. They found no difference in death at 6 months, but did find an increased rate of in-hospital recurrent MIs, with 0.9% of the control group and 5.5% of the oxygen intervention arm suffering recurrence (P = .006).⁸ They also showed a larger area of myocardial infarct in the oxygen group, as measured by peak creatine kinase levels and cardiac MRI at 6 months.

Proposed mechanisms of increased myocardial injury from hyperoxia include increased coronary vascular resistance resulting in decreased myocardial perfusion, and increased reperfusion injury from formation of free radicals.⁹

Dr. Tubbesing is a senior resident in medicine at the University of Washington, Seattle. Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

References

1. Am Heart J. 2005 Jun;149(6):1043-9.

2. J Interv Cardiol. 2017 Nov 22. doi: 10.1111/joic.12464.

3. Clin Res Cardiol. 2015 Sep;104(9):727-34.

4. Eur Heart J. 2016 Apr 1;37(13):1063-71.

5. BMJ. 1900 Dec 1;2(2083):1568.

6. JAMA. 1930 May 3;94(18):1363-5.

7. Br Med J. 1976 May 8;1(6018):1121-3.

8. Circulation. 2015 Jun 16;131(24):2143-50.

9. Cochrane Database Syst Rev. 2016 Dec 19;12:CD007160.

10. N Engl J Med. 2017 Sep 28;377(13):1240-9.

A 66-year-old man presents with substernal chest pressure and dyspnea that has been present for 45 minutes. He has nausea. Vital signs: blood pressure, 110/60; pulse, 100; oxygen saturation, 92%. Neck: elevated jugular venous pressure. Chest: clear. Cardiac: normal S1 S2, no murmurs. ECG: ST elevation in 2, 3, and aVF leads.

Which of these treatments do you recommend?

A. Morphine, oxygen, nitroglycerin, and aspirin (ASA).

B. Oxygen, morphine, ASA.

C. ASA.

In this patient, I think the correct approach would be to just give aspirin. Nitroglycerin would be problematic, as it appears that this patient might be having a right ventricular infarct, and lowering right-sided filling pressures with nitroglycerin may lead to severe hypotension.

There is controversy over the safety of routine morphine use for patients with chest pain.

Trip J. Meine, MD, and colleagues found that use of morphine either alone or in combination with nitroglycerin for patients presenting with non–ST-elevation acute coronary syndrome (NSTE-ACS) was associated with higher mortality.¹ Cian P. McCarthy, MD, and colleagues found the same results, with morphine use associated with larger infarct size, a longer hospital stay, and a trend toward increased mortality in invasively managed NSTE-ACS patients.² Suzanne de Waha and colleagues found that morphine use in patients with ST-segment elevation MIs had larger infarct size and less reperfusion success, as measured by cardiac MRI.³

Not all recent studies show a detrimental effect of morphine. Etienne Puymirat et al. reviewed in-hospital complications (death, nonfatal re-MI, stroke, stent thrombosis, and bleeding) and 1-year survival according to prehospital morphine use in 2,438 ST-elevation MI (STEMI) patients from the French Registry of Acute ST-elevation and non–ST-elevation Myocardial Infarction (FAST-MI).⁴ They found no increase in in-hospital complications or 1-year mortality.

The practice of using supplemental oxygen to treat all patients with MI became standard nearly a century ago, after oxygen was found in 1900 to relieve angina, and led to clinical improvement in four MI patients in a 1930 case series.^5,6

It was not studied in a controlled trial until 1976, when J.M. Rawles, MD, and colleagues randomized 157 patients with MI to 24 hours of oxygen at 8 L/min or to ambient air. They found no difference in mortality between the groups, but they did find a higher burden of MI in the intervention arm receiving supplemental oxygen, as measured by mean serum aspartate aminotransferase levels.⁷

The topic was not addressed again in a significant randomized trial until this century. Most notably, two recent studies again demonstrated no benefit of supplemental oxygen in normoxemic patients with MI.

In the AVOID trial in 2015, Dion Stub, MD, PhD, and colleagues randomized 441 patients with STEMI to oxygen at 8 L/min – from diagnosis in an ambulance until after cardiac catheterization – or to ambient air. They found no difference in death at 6 months, but did find an increased rate of in-hospital recurrent MIs, with 0.9% of the control group and 5.5% of the oxygen intervention arm suffering recurrence (P = .006).⁸ They also showed a larger area of myocardial infarct in the oxygen group, as measured by peak creatine kinase levels and cardiac MRI at 6 months.

Proposed mechanisms of increased myocardial injury from hyperoxia include increased coronary vascular resistance resulting in decreased myocardial perfusion, and increased reperfusion injury from formation of free radicals.⁹

Dr. Tubbesing is a senior resident in medicine at the University of Washington, Seattle. Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

References

1. Am Heart J. 2005 Jun;149(6):1043-9.

2. J Interv Cardiol. 2017 Nov 22. doi: 10.1111/joic.12464.

3. Clin Res Cardiol. 2015 Sep;104(9):727-34.

4. Eur Heart J. 2016 Apr 1;37(13):1063-71.

5. BMJ. 1900 Dec 1;2(2083):1568.

6. JAMA. 1930 May 3;94(18):1363-5.

7. Br Med J. 1976 May 8;1(6018):1121-3.

8. Circulation. 2015 Jun 16;131(24):2143-50.

9. Cochrane Database Syst Rev. 2016 Dec 19;12:CD007160.

10. N Engl J Med. 2017 Sep 28;377(13):1240-9.

A 50-year-old man returns for follow-up of hypertension. He is currently taking 20 mg of lisinopril. His blood pressure readings over the past month are 150/96, 155/98, 160/94, and 162/96. His renal function is normal, and he has been taking his lisinopril regularly.

What do you recommend?

A. Increase his lisinopril to 20 mg twice a day.

B. Switch to valsartan.

C. Add amlodipine.

But is there much benefit in doubling the dose of antihypertensive medications?

H.J. Gomez and colleagues studied the dose response of lisinopril in essential hypertension.² Patients received very-low-dose (1.25 mg or 5 mg), moderate-dose (20 mg), or high-dose (80 mg) lisinopril. The difference in blood pressure reduction between 20 mg and 80 mg was modest (5 mm/3 mm less in those receiving 80 mg, compared with 20 mg). There was no clinical effect at 1.25 mg of lisinopril, but a relatively flat dose response above 20 mg.

A similar finding was reported by J.R. Benz and colleagues in regard to escalating doses of valsartan.³ The study looked at blood pressure in response to valsartan at doses of 80 mg and 160 mg, and in combination with hydrochlorothiazide. The difference in blood pressure between valsartan 160 mg and 80 mg was 3 mm/0.8 mm. The difference in blood pressure between patients taking 80 mg of valsartan and 25 mg hydrochlorothiazide, compared with those taking 80 mg of valsartan, was 12/6.

In a meta-analysis of 354 randomized trials of fixed-dose blood pressure medications, M.R. Law and colleagues found that cutting the doses in half only reduced effectiveness of lowering BP by 20%.⁴ The average reduction in systolic BP was 9.1 mm Hg, and reduction in diastolic BP was 5.5mm Hg – which only was reduced to 7.1 mm Hg/4.4 mm Hg when the doses of medications were cut in half. Side effects attributed to beta-blockers, calcium channel blockers, and diuretics were very dose related, whereas the side effects attributed to ACE inhibitors were not.

In another meta-analysis comparing monotherapy vs. combination therapy for lowering blood pressure, adding another drug lowered blood pressure fivefold more than doubling the dose of the initial antihypertensive drug.⁵

I think the right answer in this case would be to add amlodipine instead of doubling the dose of lisinopril or switching to valsartan as a single agent. The data are striking on how little effect there is in increasing antihypertensive medication doses. Adding another antihypertensive medication should be the standard practice when the first medication started does not achieve the desired goal.
 

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

References

1. JAMA. 2003 May 21;289(19):2560-72.

2. Br J Clin Pharm. 1989;28:415-20.

3. J Hum Hypertens. 1998 Dec;12(12):861-6.

4. BMJ. 2003 Jun 28;326(7404):1427.

5. Am J Med. 2009 Mar;122(3):290-300.

A 50-year-old man returns for follow-up of hypertension. He is currently taking 20 mg of lisinopril. His blood pressure readings over the past month are 150/96, 155/98, 160/94, and 162/96. His renal function is normal, and he has been taking his lisinopril regularly.

What do you recommend?

A. Increase his lisinopril to 20 mg twice a day.

B. Switch to valsartan.

C. Add amlodipine.

But is there much benefit in doubling the dose of antihypertensive medications?

H.J. Gomez and colleagues studied the dose response of lisinopril in essential hypertension.² Patients received very-low-dose (1.25 mg or 5 mg), moderate-dose (20 mg), or high-dose (80 mg) lisinopril. The difference in blood pressure reduction between 20 mg and 80 mg was modest (5 mm/3 mm less in those receiving 80 mg, compared with 20 mg). There was no clinical effect at 1.25 mg of lisinopril, but a relatively flat dose response above 20 mg.

A similar finding was reported by J.R. Benz and colleagues in regard to escalating doses of valsartan.³ The study looked at blood pressure in response to valsartan at doses of 80 mg and 160 mg, and in combination with hydrochlorothiazide. The difference in blood pressure between valsartan 160 mg and 80 mg was 3 mm/0.8 mm. The difference in blood pressure between patients taking 80 mg of valsartan and 25 mg hydrochlorothiazide, compared with those taking 80 mg of valsartan, was 12/6.

In a meta-analysis of 354 randomized trials of fixed-dose blood pressure medications, M.R. Law and colleagues found that cutting the doses in half only reduced effectiveness of lowering BP by 20%.⁴ The average reduction in systolic BP was 9.1 mm Hg, and reduction in diastolic BP was 5.5mm Hg – which only was reduced to 7.1 mm Hg/4.4 mm Hg when the doses of medications were cut in half. Side effects attributed to beta-blockers, calcium channel blockers, and diuretics were very dose related, whereas the side effects attributed to ACE inhibitors were not.

In another meta-analysis comparing monotherapy vs. combination therapy for lowering blood pressure, adding another drug lowered blood pressure fivefold more than doubling the dose of the initial antihypertensive drug.⁵

I think the right answer in this case would be to add amlodipine instead of doubling the dose of lisinopril or switching to valsartan as a single agent. The data are striking on how little effect there is in increasing antihypertensive medication doses. Adding another antihypertensive medication should be the standard practice when the first medication started does not achieve the desired goal.
 

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

References

1. JAMA. 2003 May 21;289(19):2560-72.

2. Br J Clin Pharm. 1989;28:415-20.

3. J Hum Hypertens. 1998 Dec;12(12):861-6.

4. BMJ. 2003 Jun 28;326(7404):1427.

5. Am J Med. 2009 Mar;122(3):290-300.

A 50-year-old man returns for follow-up of hypertension. He is currently taking 20 mg of lisinopril. His blood pressure readings over the past month are 150/96, 155/98, 160/94, and 162/96. His renal function is normal, and he has been taking his lisinopril regularly.

What do you recommend?

A. Increase his lisinopril to 20 mg twice a day.

B. Switch to valsartan.

C. Add amlodipine.

But is there much benefit in doubling the dose of antihypertensive medications?

H.J. Gomez and colleagues studied the dose response of lisinopril in essential hypertension.² Patients received very-low-dose (1.25 mg or 5 mg), moderate-dose (20 mg), or high-dose (80 mg) lisinopril. The difference in blood pressure reduction between 20 mg and 80 mg was modest (5 mm/3 mm less in those receiving 80 mg, compared with 20 mg). There was no clinical effect at 1.25 mg of lisinopril, but a relatively flat dose response above 20 mg.

A similar finding was reported by J.R. Benz and colleagues in regard to escalating doses of valsartan.³ The study looked at blood pressure in response to valsartan at doses of 80 mg and 160 mg, and in combination with hydrochlorothiazide. The difference in blood pressure between valsartan 160 mg and 80 mg was 3 mm/0.8 mm. The difference in blood pressure between patients taking 80 mg of valsartan and 25 mg hydrochlorothiazide, compared with those taking 80 mg of valsartan, was 12/6.

In a meta-analysis of 354 randomized trials of fixed-dose blood pressure medications, M.R. Law and colleagues found that cutting the doses in half only reduced effectiveness of lowering BP by 20%.⁴ The average reduction in systolic BP was 9.1 mm Hg, and reduction in diastolic BP was 5.5mm Hg – which only was reduced to 7.1 mm Hg/4.4 mm Hg when the doses of medications were cut in half. Side effects attributed to beta-blockers, calcium channel blockers, and diuretics were very dose related, whereas the side effects attributed to ACE inhibitors were not.

In another meta-analysis comparing monotherapy vs. combination therapy for lowering blood pressure, adding another drug lowered blood pressure fivefold more than doubling the dose of the initial antihypertensive drug.⁵

I think the right answer in this case would be to add amlodipine instead of doubling the dose of lisinopril or switching to valsartan as a single agent. The data are striking on how little effect there is in increasing antihypertensive medication doses. Adding another antihypertensive medication should be the standard practice when the first medication started does not achieve the desired goal.
 

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

References

1. JAMA. 2003 May 21;289(19):2560-72.

2. Br J Clin Pharm. 1989;28:415-20.

3. J Hum Hypertens. 1998 Dec;12(12):861-6.

4. BMJ. 2003 Jun 28;326(7404):1427.

5. Am J Med. 2009 Mar;122(3):290-300.

A 66-year-old woman 3 years status post hip replacement is seen for dental work. The dentist contacts the clinic for an antibiotic prescription. The patient has a penicillin allergy (rash). What do you recommend?

A. Clindamycin one dose before dental work.

B. Amoxicillin one dose before dental work.

C. Amoxicillin one dose before, one dose 4 hours after dental work.

D. Clindamycin one dose before dental work, one dose 4 hours after dental work.

E. No antibiotics.

Many patients with prosthetic joints will request antibiotics to take prior to dental procedures. Sometimes this request comes from the dental office.

When I ask patients why they feel they need antibiotics, they often reply that they were told by their orthopedic surgeons or their dentist that they would need to take antibiotics before dental procedures.

In an era when Clostridium difficile infection is a common and dangerous complication in the elderly, avoidance of unnecessary antibiotics is critical. In the United States, it is estimated that there are 240,000 patients infected with C. difficile annually, with 24,000 deaths at a cost of $6 billion.¹

Is there compelling evidence to justify giving antibiotic prophylaxis for dental procedures to patients with prosthetic joints?

References

1. Steckelberg J.M., Osmon D.R. Prosthetic joint infections. In: Bisno A.L., Waldvogel F.A., eds. Infections associated with indwelling medical devices. Third ed., Washington, D.C.: American Society of Microbiology Press, 2000:173-209.

2. J Dent Res. 2004 Feb;83(2):170-4.

3. J Clin Periodontol. 2006 Feb;33(6):401-7.

4. J Am Dent Assoc. 1997 Jul;128(7):1004-8.

5. J Am Dent Assoc. 2003 Jul;134(7):895-9.

6. Spec Care Dentist. 2009 Nov-Dec;29(6):229-31.

7. Clin Infect Dis. 2010 Jan 1;50(1):8-16.

8. J Dent (Shiraz). 2013 Mar;14(1):49-52.

9. Infect Control Hosp Epidemiol. 2017 Feb;38(2):154-61.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

A 66-year-old woman 3 years status post hip replacement is seen for dental work. The dentist contacts the clinic for an antibiotic prescription. The patient has a penicillin allergy (rash). What do you recommend?

A. Clindamycin one dose before dental work.

B. Amoxicillin one dose before dental work.

C. Amoxicillin one dose before, one dose 4 hours after dental work.

D. Clindamycin one dose before dental work, one dose 4 hours after dental work.

E. No antibiotics.

Many patients with prosthetic joints will request antibiotics to take prior to dental procedures. Sometimes this request comes from the dental office.

When I ask patients why they feel they need antibiotics, they often reply that they were told by their orthopedic surgeons or their dentist that they would need to take antibiotics before dental procedures.

In an era when Clostridium difficile infection is a common and dangerous complication in the elderly, avoidance of unnecessary antibiotics is critical. In the United States, it is estimated that there are 240,000 patients infected with C. difficile annually, with 24,000 deaths at a cost of $6 billion.¹

Is there compelling evidence to justify giving antibiotic prophylaxis for dental procedures to patients with prosthetic joints?

References

1. Steckelberg J.M., Osmon D.R. Prosthetic joint infections. In: Bisno A.L., Waldvogel F.A., eds. Infections associated with indwelling medical devices. Third ed., Washington, D.C.: American Society of Microbiology Press, 2000:173-209.

2. J Dent Res. 2004 Feb;83(2):170-4.

3. J Clin Periodontol. 2006 Feb;33(6):401-7.

4. J Am Dent Assoc. 1997 Jul;128(7):1004-8.

5. J Am Dent Assoc. 2003 Jul;134(7):895-9.

6. Spec Care Dentist. 2009 Nov-Dec;29(6):229-31.

7. Clin Infect Dis. 2010 Jan 1;50(1):8-16.

8. J Dent (Shiraz). 2013 Mar;14(1):49-52.

9. Infect Control Hosp Epidemiol. 2017 Feb;38(2):154-61.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

A 66-year-old woman 3 years status post hip replacement is seen for dental work. The dentist contacts the clinic for an antibiotic prescription. The patient has a penicillin allergy (rash). What do you recommend?

A. Clindamycin one dose before dental work.

B. Amoxicillin one dose before dental work.

C. Amoxicillin one dose before, one dose 4 hours after dental work.

D. Clindamycin one dose before dental work, one dose 4 hours after dental work.

E. No antibiotics.

Many patients with prosthetic joints will request antibiotics to take prior to dental procedures. Sometimes this request comes from the dental office.

When I ask patients why they feel they need antibiotics, they often reply that they were told by their orthopedic surgeons or their dentist that they would need to take antibiotics before dental procedures.

In an era when Clostridium difficile infection is a common and dangerous complication in the elderly, avoidance of unnecessary antibiotics is critical. In the United States, it is estimated that there are 240,000 patients infected with C. difficile annually, with 24,000 deaths at a cost of $6 billion.¹

Is there compelling evidence to justify giving antibiotic prophylaxis for dental procedures to patients with prosthetic joints?

References

1. Steckelberg J.M., Osmon D.R. Prosthetic joint infections. In: Bisno A.L., Waldvogel F.A., eds. Infections associated with indwelling medical devices. Third ed., Washington, D.C.: American Society of Microbiology Press, 2000:173-209.

2. J Dent Res. 2004 Feb;83(2):170-4.

3. J Clin Periodontol. 2006 Feb;33(6):401-7.

4. J Am Dent Assoc. 1997 Jul;128(7):1004-8.

5. J Am Dent Assoc. 2003 Jul;134(7):895-9.

6. Spec Care Dentist. 2009 Nov-Dec;29(6):229-31.

7. Clin Infect Dis. 2010 Jan 1;50(1):8-16.

8. J Dent (Shiraz). 2013 Mar;14(1):49-52.

9. Infect Control Hosp Epidemiol. 2017 Feb;38(2):154-61.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

A 28-year-old male presents to the emergency department with fever and severe headache. He has had a fever for 24 hours. Headache began that morning. On exam, he has marked nuchal rigidity, with a temperature of 103.5° F. He is fully oriented and has a nonfocal neurologic examination.

What would you do?

A) Lumbar puncture (LP).

B) CT scan, then LP.

C) Antibiotics, CT scan, then LP.

D) MRI, then LP.

E) Antibiotics, MRI, then LP.

The practice of obtaining a head CT scan (or MRI) before performing a lumbar puncture (LP) is commonplace in emergency departments. The concern is that if a lumbar puncture is done in a patient with increased intracranial pressure, then brain herniation could occur. How common is brain herniation, are there useful clinical indicators that make a CT scan not helpful, and does this concern reach myth status?

References

1. Br J Radiol. 1999 Mar;72(855):319.

2. J Emerg Med. 1994 Sep-Oct;12(5):597-601.

3. AMA Arch Neurol Psychiatry. 1954 Nov;72(5):568-72.

4. Postgrad Med J. 2006 Mar;82(965):162-5.

5. N Engl J Med. 2001 Dec 13;345(24):1727-33.
 

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

A 28-year-old male presents to the emergency department with fever and severe headache. He has had a fever for 24 hours. Headache began that morning. On exam, he has marked nuchal rigidity, with a temperature of 103.5° F. He is fully oriented and has a nonfocal neurologic examination.

What would you do?

A) Lumbar puncture (LP).

B) CT scan, then LP.

C) Antibiotics, CT scan, then LP.

D) MRI, then LP.

E) Antibiotics, MRI, then LP.

The practice of obtaining a head CT scan (or MRI) before performing a lumbar puncture (LP) is commonplace in emergency departments. The concern is that if a lumbar puncture is done in a patient with increased intracranial pressure, then brain herniation could occur. How common is brain herniation, are there useful clinical indicators that make a CT scan not helpful, and does this concern reach myth status?

References

1. Br J Radiol. 1999 Mar;72(855):319.

2. J Emerg Med. 1994 Sep-Oct;12(5):597-601.

3. AMA Arch Neurol Psychiatry. 1954 Nov;72(5):568-72.

4. Postgrad Med J. 2006 Mar;82(965):162-5.

5. N Engl J Med. 2001 Dec 13;345(24):1727-33.
 

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

A 28-year-old male presents to the emergency department with fever and severe headache. He has had a fever for 24 hours. Headache began that morning. On exam, he has marked nuchal rigidity, with a temperature of 103.5° F. He is fully oriented and has a nonfocal neurologic examination.

What would you do?

A) Lumbar puncture (LP).

B) CT scan, then LP.

C) Antibiotics, CT scan, then LP.

D) MRI, then LP.

E) Antibiotics, MRI, then LP.

The practice of obtaining a head CT scan (or MRI) before performing a lumbar puncture (LP) is commonplace in emergency departments. The concern is that if a lumbar puncture is done in a patient with increased intracranial pressure, then brain herniation could occur. How common is brain herniation, are there useful clinical indicators that make a CT scan not helpful, and does this concern reach myth status?

References

1. Br J Radiol. 1999 Mar;72(855):319.

2. J Emerg Med. 1994 Sep-Oct;12(5):597-601.

3. AMA Arch Neurol Psychiatry. 1954 Nov;72(5):568-72.

4. Postgrad Med J. 2006 Mar;82(965):162-5.

5. N Engl J Med. 2001 Dec 13;345(24):1727-33.
 

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected].

A 55-year-old man presents to the emergency department with substernal chest pain. The pain has occurred off and on over the past 2 hours. He has no family history of coronary artery disease. He has no history of diabetes, hypertension, or cigarette smoking. His most recent total cholesterol was 220 mg/dL (HDL, 40; LDL, 155). Blood pressure is 130/70. An ECG obtained on arrival is unremarkable. When he reached the ED, he received a nitroglycerin tablet with resolution of his pain within 4 minutes.

What is the most accurate statement?

A. The chance of CAD in this man over the next 10 years was 8% before his symptoms and is now greater than 20%.

B. The chance of CAD in this man over the next 10 years was 8% and is still 8%.

C. The chance of CAD in this man over the next 10 years was 15% before his symptoms and is now close to 100%.

D. The chance of CAD in this man over the next 10 years was 15% before his symptoms and is now close to 50%.

For years, giving nitroglycerin to patients who present with chest pain has been considered a good therapy, and the response to the medication has been considered a sign that the pain was likely due to cardiac ischemia. Is there evidence that this is true?

References

1. Am J Cardiol. 2002 Dec 1;90(11):1264-6.

2. Ann Emerg Med. 2005 Jun;45(6):581-5.

3. CJEM. 2006 May;8(3):164-9.

4. Ann Intern Med. 2003 Dec 16;139(12):979-86.

5. Emerg Med J. 2012 Mar;29(3):173-6.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected] .

A 55-year-old man presents to the emergency department with substernal chest pain. The pain has occurred off and on over the past 2 hours. He has no family history of coronary artery disease. He has no history of diabetes, hypertension, or cigarette smoking. His most recent total cholesterol was 220 mg/dL (HDL, 40; LDL, 155). Blood pressure is 130/70. An ECG obtained on arrival is unremarkable. When he reached the ED, he received a nitroglycerin tablet with resolution of his pain within 4 minutes.

What is the most accurate statement?

A. The chance of CAD in this man over the next 10 years was 8% before his symptoms and is now greater than 20%.

B. The chance of CAD in this man over the next 10 years was 8% and is still 8%.

C. The chance of CAD in this man over the next 10 years was 15% before his symptoms and is now close to 100%.

D. The chance of CAD in this man over the next 10 years was 15% before his symptoms and is now close to 50%.

For years, giving nitroglycerin to patients who present with chest pain has been considered a good therapy, and the response to the medication has been considered a sign that the pain was likely due to cardiac ischemia. Is there evidence that this is true?

References

1. Am J Cardiol. 2002 Dec 1;90(11):1264-6.

2. Ann Emerg Med. 2005 Jun;45(6):581-5.

3. CJEM. 2006 May;8(3):164-9.

4. Ann Intern Med. 2003 Dec 16;139(12):979-86.

5. Emerg Med J. 2012 Mar;29(3):173-6.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected] .

A 55-year-old man presents to the emergency department with substernal chest pain. The pain has occurred off and on over the past 2 hours. He has no family history of coronary artery disease. He has no history of diabetes, hypertension, or cigarette smoking. His most recent total cholesterol was 220 mg/dL (HDL, 40; LDL, 155). Blood pressure is 130/70. An ECG obtained on arrival is unremarkable. When he reached the ED, he received a nitroglycerin tablet with resolution of his pain within 4 minutes.

What is the most accurate statement?

A. The chance of CAD in this man over the next 10 years was 8% before his symptoms and is now greater than 20%.

B. The chance of CAD in this man over the next 10 years was 8% and is still 8%.

C. The chance of CAD in this man over the next 10 years was 15% before his symptoms and is now close to 100%.

D. The chance of CAD in this man over the next 10 years was 15% before his symptoms and is now close to 50%.

For years, giving nitroglycerin to patients who present with chest pain has been considered a good therapy, and the response to the medication has been considered a sign that the pain was likely due to cardiac ischemia. Is there evidence that this is true?

References

1. Am J Cardiol. 2002 Dec 1;90(11):1264-6.

2. Ann Emerg Med. 2005 Jun;45(6):581-5.

3. CJEM. 2006 May;8(3):164-9.

4. Ann Intern Med. 2003 Dec 16;139(12):979-86.

5. Emerg Med J. 2012 Mar;29(3):173-6.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at [email protected] .