User login
Obstructive sleep apnea (OSA) is a potentially serious sleep disorder in which breathing repeatedly stops and starts during sleep. OSA occurs when the throat muscles intermittently relax and block the airway during sleep. The condition is usually associated with several other chronic medical conditions leading to poor quality of life.
It is estimated that at least 25 million adults are affected by OSA in the United States. Further, the obesity epidemic has increased the prevalence of OSA in the last 2 decades. The prevalence of OSA can be higher in patients undergoing surgery. For example, 70% of the patients undergoing bariatric surgery have OSA, whereas 48% of patients undergoing cardiac surgery have moderate-severe OSA. Alarmingly, in 80% of patients with moderate-severe OSA, the disorder remains undiagnosed and untreated, threatening public health and safety.
Patients with OSA can experience multiple complications when receiving sedatives and opioids during anesthesia (Opperer. Anesthesia and Analgesia. 122[5]:1321). These drugs may diminish the protective arousal reflex triggered by bouts of hypoxia, thereby increasing the risk of prolonged periods of apnea and possibly respiratory arrest. Sedatives and narcotics can decrease pharyngeal muscle tone, which can worsen the existing OSA and increase upper airway resistance. Undiagnosed and untreated OSA may be a contributing factor in many of these complications. Effective screening/diagnosis and treatment of OSA are considered to be important steps to reduce health-care spending, improve chronic disease management, and reduce complications.
The STOP-Bang Questionnaire
The gold standard for the diagnosis of OSA is overnight polysomnography. However, it is time consuming, labor intensive, and costly. The STOP-Bang Questionnaire is considered to be the most validated screening tool for OSA for various populations (Nagappa et al. PLoS One. 2015;10[12]:e0143697).
The STOP-Bang Questionnaire includes four questions used in the STOP Questionnaire plus four additional demographic queries, a total of eight dichotomous (yes/no) questions related to the clinical features of sleep apnea (Snoring, Tiredness, Observed apnea, high blood Pressure, BMI, age, neck circumference, and male gender). For each question, answering “yes” scores 1, a “no” response scores 0, and the total score ranges from 0 to 8 (see www.stopbang.ca). The Questionnaire can be completed quickly and easily (usually within 1-2 minutes), and the overall response rates are typically high (90%-100%). Because of its ease of use, efficiency, and high sensitivity, the STOP-Bang Questionnaire has been widely adopted in various populations, such as sleep clinics and the surgical and general population.
The STOP-Bang Questionnaire has demonstrated a high sensitivity using a cutoff score of greater than or equal to 3: 84% in detecting any sleep apnea (apnea-hypopnea index greater than 5 events/h), 93% in detecting moderate to severe sleep apnea (AHI greater than 15 events/h), and almost 100% in detecting severe sleep apnea (AHI greater than 30 events/h). The corresponding specificities were 56.4%, 43%, and 37% (Chung et al. Anesthesiology. 2008;108[5]:812). If patients score 0-2 on the STOP-Bang Questionnaire, they are considered to be at low risk of OSA, and the possibility of moderate to severe sleep apnea can be ruled out.
The modest specificity of the STOP-Bang Questionnaire may yield moderately high false-positive cases. This may lead to unwanted sleep study referrals and increased health care expenditure. There are several ways by which the specificity can be improved, thereby decreasing false-positive rates.
Setting a threshold for the STOP-Bang scores in different population
The main advantage of the STOP-Bang scores is its flexibility to use different scores for different populations. For example, in a bariatric population, a STOP-Bang score of greater than or equal to 4 can be used. On the other hand, in an ENT population, where we would like to identify a majority of patients with moderate-severe OSA, a STOP-Bang score of greater than or equal to 5 can be used. In the sleep clinic population, as the STOP-Bang score cut-off increased from 3 to 8, the specificity increased from 52% to 100%, and the PPV increased continuously from 93% to 100% for any OSA (AHI greater than or equal to 5). A similar pattern was seen in the surgical population, as the STOP-Bang score cutoff increased from 3 to greater than or equal to 7, the specificity increased from 40% to 98%, and the PPV increased from 75% to 82% for any OSA (AHI greater than or equal to 5) (Nagappa et al. PLoS One. 2015;10[12]:e0143697).
Regional practices should decide the appropriate threshold of screening tests, after considering the implications for missed diagnoses and cost of care. There is a trade-off between sensitivity and specificity. At lower thresholds, there is improved sensitivity with potentially increased resource utilization, whereas increasing the threshold will result in loss of sensitivity and increased false-negative rates but improved resource utilization. A higher threshold should be adopted in the population with a lower prevalence of OSA.
STOP-Bang score and probability of OSA
In both sleep clinic patients (Fig 1; Panel A) and surgical patients (Fig 1; Panel B), the probability of moderate-to-severe OSA or severe OSA increased a s the STOP-Bang score increased from 3 to 7/8. With higher scores, there is a more profound increase in the probability of severe OSA, compared with moderate OSA (Chung et al. Br J Anaesth. 2012;108[5]:768).
Alternative models for scoring the STOP-Bang Questionnaire
The individual items on the Questionnaire do not share an equal predictive weight for OSA. In the “Bang” components, body mass index greater than 35 kg/m2, neck circumference greater than 40 cm, and male gender are more predictive than age greater than 50 years. The predictive performance of the specific combinations of items has been explored. Compared with the specificity of 31% for detecting moderate to severe OSA, specific combinations significantly improve the specificity to detect any OSA (AHI greater than 5), moderate to severe OSA (AHI greater than 15), and severe OSA (AHI greater than 30) at the expense of sensitivity. The specificity to detect moderate to severe OSA increases to 85% for a STOP score greater than or equal to 2 + BMI greater than 35 kg/m2; to 79% for a STOP score greater than or equal to 2 + neck circumference > greater than 40 cm (16 in); and to 77% for a STOP score greater than or equal to 2 + male, respectively. These combinations can assist in accurately identifying more patients with moderate to severe OSA (Chung et al. J Clin Sleep Med. 2014;10[9]:951).
The STOP-Bang Questionnaire and serum bicarbonate
Serum bicarbonate (HCO3–) is significantly correlated to AHI, and the addition of serum HCO3– greater than or equal to 28 mmol/L to a STOP-Bang score greater than or equal to 3 improves the specificity to predict moderate-severe OSA but decreases its sensitivity (Chung et al. Chest. 2013;143[5]:1284). For a STOP-Bang score of greater than or equal to 3 + HCO3– greater than or equal to 28 mmol/L), the specificity for detecting moderate to severe OSA increases from 30% to 82%, and from 28% to 80% for detecting severe OSA, respectively.
A two-step strategy for using STOP-Bang Questionnaire
A two-step algorithm using the STOP-Bang Questionnaire identifies patients effectively with a high probability of moderate to severe sleep apnea (Fig 2) (Chung et al. Chest. 2016;149[3]:631). The first step is to check the STOP-Bang score. If a patient scores 0-2 on the STOP-Bang Questionnaire, he or she is unlikely to have moderate to severe OSA. Conversely, a patient with a STOP-Bang score of 5-8 has a high probability of moderate to severe OSA.
The second step is for the patients with STOP-Bang scores of 3 or 4. These patients can be further classified as having a higher risk for moderate to severe OSA if one of the following conditions is met: (1) a STOP score greater than or equal to 2 + BMI greater than 35 kg/m2; (2) a STOP score greater than or equal to 2 + male gender; (3) a STOP score greater than or equal to 2 + neck circumference greater than 40 cm (16 in); or (4) a STOP-Bang score greater than or equal to 3 + serum HCO3– greater than or equal to 28 mmol/L.
The STOP-Bang Questionnaire and perioperative complications
The STOP-Bang Questionnaire not only identifies the high-risk patients with OSA but also may have a strong association toward predicting perioperative complications (Vasu et al. Arch Otolaryngol Head Neck Surg. 2010;136[10]:1020). The important step of screening patients with OSA using the STOP-Bang Questionnaire may create an awareness among the perioperative team resulting in decreased complications (Veenstra et al. Crit Care Nurs Clin N Am. 2014;26[4]:499).
The Joint Commission’s Division of Healthcare Improvement has raised strong concerns regarding the lack of training for health-care professionals to recognize OSA. A recent guideline published by the Society of Anesthesia and Sleep Medicine recommends using a screening tool to identify high-risk patients with OSA (Chung et al. Anesthesia Analgesia. 2016;June 1: Epub ahead of print).
There is preliminary evidence that patients with diagnosed OSA and a CPAP prescription had significantly reduced postoperative cardiovascular complications (cardiac arrest and shock) by more than 50% vs patients with undiagnosed OSA (Mutter et al. Anesthesiology. 2014;121[4]:707).
Conclusion
The STOP-Bang Questionnaire is a simple, practical, and flexible screening tool to identify the high-risk OSA patients. More information is available at www.stopbang.ca.
Dr. Chung is with the department of anesthesia, Toronto Western Hospital – University Health Network, University of Toronto, ON, Canada; Dr. Nagappa is with the department of anesthesia & perioperative medicine, London Health Sciences Centre and St. Joseph Health Care London, Western University, London, ON, Canada.
Obstructive sleep apnea (OSA) is a potentially serious sleep disorder in which breathing repeatedly stops and starts during sleep. OSA occurs when the throat muscles intermittently relax and block the airway during sleep. The condition is usually associated with several other chronic medical conditions leading to poor quality of life.
It is estimated that at least 25 million adults are affected by OSA in the United States. Further, the obesity epidemic has increased the prevalence of OSA in the last 2 decades. The prevalence of OSA can be higher in patients undergoing surgery. For example, 70% of the patients undergoing bariatric surgery have OSA, whereas 48% of patients undergoing cardiac surgery have moderate-severe OSA. Alarmingly, in 80% of patients with moderate-severe OSA, the disorder remains undiagnosed and untreated, threatening public health and safety.
Patients with OSA can experience multiple complications when receiving sedatives and opioids during anesthesia (Opperer. Anesthesia and Analgesia. 122[5]:1321). These drugs may diminish the protective arousal reflex triggered by bouts of hypoxia, thereby increasing the risk of prolonged periods of apnea and possibly respiratory arrest. Sedatives and narcotics can decrease pharyngeal muscle tone, which can worsen the existing OSA and increase upper airway resistance. Undiagnosed and untreated OSA may be a contributing factor in many of these complications. Effective screening/diagnosis and treatment of OSA are considered to be important steps to reduce health-care spending, improve chronic disease management, and reduce complications.
The STOP-Bang Questionnaire
The gold standard for the diagnosis of OSA is overnight polysomnography. However, it is time consuming, labor intensive, and costly. The STOP-Bang Questionnaire is considered to be the most validated screening tool for OSA for various populations (Nagappa et al. PLoS One. 2015;10[12]:e0143697).
The STOP-Bang Questionnaire includes four questions used in the STOP Questionnaire plus four additional demographic queries, a total of eight dichotomous (yes/no) questions related to the clinical features of sleep apnea (Snoring, Tiredness, Observed apnea, high blood Pressure, BMI, age, neck circumference, and male gender). For each question, answering “yes” scores 1, a “no” response scores 0, and the total score ranges from 0 to 8 (see www.stopbang.ca). The Questionnaire can be completed quickly and easily (usually within 1-2 minutes), and the overall response rates are typically high (90%-100%). Because of its ease of use, efficiency, and high sensitivity, the STOP-Bang Questionnaire has been widely adopted in various populations, such as sleep clinics and the surgical and general population.
The STOP-Bang Questionnaire has demonstrated a high sensitivity using a cutoff score of greater than or equal to 3: 84% in detecting any sleep apnea (apnea-hypopnea index greater than 5 events/h), 93% in detecting moderate to severe sleep apnea (AHI greater than 15 events/h), and almost 100% in detecting severe sleep apnea (AHI greater than 30 events/h). The corresponding specificities were 56.4%, 43%, and 37% (Chung et al. Anesthesiology. 2008;108[5]:812). If patients score 0-2 on the STOP-Bang Questionnaire, they are considered to be at low risk of OSA, and the possibility of moderate to severe sleep apnea can be ruled out.
The modest specificity of the STOP-Bang Questionnaire may yield moderately high false-positive cases. This may lead to unwanted sleep study referrals and increased health care expenditure. There are several ways by which the specificity can be improved, thereby decreasing false-positive rates.
Setting a threshold for the STOP-Bang scores in different population
The main advantage of the STOP-Bang scores is its flexibility to use different scores for different populations. For example, in a bariatric population, a STOP-Bang score of greater than or equal to 4 can be used. On the other hand, in an ENT population, where we would like to identify a majority of patients with moderate-severe OSA, a STOP-Bang score of greater than or equal to 5 can be used. In the sleep clinic population, as the STOP-Bang score cut-off increased from 3 to 8, the specificity increased from 52% to 100%, and the PPV increased continuously from 93% to 100% for any OSA (AHI greater than or equal to 5). A similar pattern was seen in the surgical population, as the STOP-Bang score cutoff increased from 3 to greater than or equal to 7, the specificity increased from 40% to 98%, and the PPV increased from 75% to 82% for any OSA (AHI greater than or equal to 5) (Nagappa et al. PLoS One. 2015;10[12]:e0143697).
Regional practices should decide the appropriate threshold of screening tests, after considering the implications for missed diagnoses and cost of care. There is a trade-off between sensitivity and specificity. At lower thresholds, there is improved sensitivity with potentially increased resource utilization, whereas increasing the threshold will result in loss of sensitivity and increased false-negative rates but improved resource utilization. A higher threshold should be adopted in the population with a lower prevalence of OSA.
STOP-Bang score and probability of OSA
In both sleep clinic patients (Fig 1; Panel A) and surgical patients (Fig 1; Panel B), the probability of moderate-to-severe OSA or severe OSA increased a s the STOP-Bang score increased from 3 to 7/8. With higher scores, there is a more profound increase in the probability of severe OSA, compared with moderate OSA (Chung et al. Br J Anaesth. 2012;108[5]:768).
Alternative models for scoring the STOP-Bang Questionnaire
The individual items on the Questionnaire do not share an equal predictive weight for OSA. In the “Bang” components, body mass index greater than 35 kg/m2, neck circumference greater than 40 cm, and male gender are more predictive than age greater than 50 years. The predictive performance of the specific combinations of items has been explored. Compared with the specificity of 31% for detecting moderate to severe OSA, specific combinations significantly improve the specificity to detect any OSA (AHI greater than 5), moderate to severe OSA (AHI greater than 15), and severe OSA (AHI greater than 30) at the expense of sensitivity. The specificity to detect moderate to severe OSA increases to 85% for a STOP score greater than or equal to 2 + BMI greater than 35 kg/m2; to 79% for a STOP score greater than or equal to 2 + neck circumference > greater than 40 cm (16 in); and to 77% for a STOP score greater than or equal to 2 + male, respectively. These combinations can assist in accurately identifying more patients with moderate to severe OSA (Chung et al. J Clin Sleep Med. 2014;10[9]:951).
The STOP-Bang Questionnaire and serum bicarbonate
Serum bicarbonate (HCO3–) is significantly correlated to AHI, and the addition of serum HCO3– greater than or equal to 28 mmol/L to a STOP-Bang score greater than or equal to 3 improves the specificity to predict moderate-severe OSA but decreases its sensitivity (Chung et al. Chest. 2013;143[5]:1284). For a STOP-Bang score of greater than or equal to 3 + HCO3– greater than or equal to 28 mmol/L), the specificity for detecting moderate to severe OSA increases from 30% to 82%, and from 28% to 80% for detecting severe OSA, respectively.
A two-step strategy for using STOP-Bang Questionnaire
A two-step algorithm using the STOP-Bang Questionnaire identifies patients effectively with a high probability of moderate to severe sleep apnea (Fig 2) (Chung et al. Chest. 2016;149[3]:631). The first step is to check the STOP-Bang score. If a patient scores 0-2 on the STOP-Bang Questionnaire, he or she is unlikely to have moderate to severe OSA. Conversely, a patient with a STOP-Bang score of 5-8 has a high probability of moderate to severe OSA.
The second step is for the patients with STOP-Bang scores of 3 or 4. These patients can be further classified as having a higher risk for moderate to severe OSA if one of the following conditions is met: (1) a STOP score greater than or equal to 2 + BMI greater than 35 kg/m2; (2) a STOP score greater than or equal to 2 + male gender; (3) a STOP score greater than or equal to 2 + neck circumference greater than 40 cm (16 in); or (4) a STOP-Bang score greater than or equal to 3 + serum HCO3– greater than or equal to 28 mmol/L.
The STOP-Bang Questionnaire and perioperative complications
The STOP-Bang Questionnaire not only identifies the high-risk patients with OSA but also may have a strong association toward predicting perioperative complications (Vasu et al. Arch Otolaryngol Head Neck Surg. 2010;136[10]:1020). The important step of screening patients with OSA using the STOP-Bang Questionnaire may create an awareness among the perioperative team resulting in decreased complications (Veenstra et al. Crit Care Nurs Clin N Am. 2014;26[4]:499).
The Joint Commission’s Division of Healthcare Improvement has raised strong concerns regarding the lack of training for health-care professionals to recognize OSA. A recent guideline published by the Society of Anesthesia and Sleep Medicine recommends using a screening tool to identify high-risk patients with OSA (Chung et al. Anesthesia Analgesia. 2016;June 1: Epub ahead of print).
There is preliminary evidence that patients with diagnosed OSA and a CPAP prescription had significantly reduced postoperative cardiovascular complications (cardiac arrest and shock) by more than 50% vs patients with undiagnosed OSA (Mutter et al. Anesthesiology. 2014;121[4]:707).
Conclusion
The STOP-Bang Questionnaire is a simple, practical, and flexible screening tool to identify the high-risk OSA patients. More information is available at www.stopbang.ca.
Dr. Chung is with the department of anesthesia, Toronto Western Hospital – University Health Network, University of Toronto, ON, Canada; Dr. Nagappa is with the department of anesthesia & perioperative medicine, London Health Sciences Centre and St. Joseph Health Care London, Western University, London, ON, Canada.
Obstructive sleep apnea (OSA) is a potentially serious sleep disorder in which breathing repeatedly stops and starts during sleep. OSA occurs when the throat muscles intermittently relax and block the airway during sleep. The condition is usually associated with several other chronic medical conditions leading to poor quality of life.
It is estimated that at least 25 million adults are affected by OSA in the United States. Further, the obesity epidemic has increased the prevalence of OSA in the last 2 decades. The prevalence of OSA can be higher in patients undergoing surgery. For example, 70% of the patients undergoing bariatric surgery have OSA, whereas 48% of patients undergoing cardiac surgery have moderate-severe OSA. Alarmingly, in 80% of patients with moderate-severe OSA, the disorder remains undiagnosed and untreated, threatening public health and safety.
Patients with OSA can experience multiple complications when receiving sedatives and opioids during anesthesia (Opperer. Anesthesia and Analgesia. 122[5]:1321). These drugs may diminish the protective arousal reflex triggered by bouts of hypoxia, thereby increasing the risk of prolonged periods of apnea and possibly respiratory arrest. Sedatives and narcotics can decrease pharyngeal muscle tone, which can worsen the existing OSA and increase upper airway resistance. Undiagnosed and untreated OSA may be a contributing factor in many of these complications. Effective screening/diagnosis and treatment of OSA are considered to be important steps to reduce health-care spending, improve chronic disease management, and reduce complications.
The STOP-Bang Questionnaire
The gold standard for the diagnosis of OSA is overnight polysomnography. However, it is time consuming, labor intensive, and costly. The STOP-Bang Questionnaire is considered to be the most validated screening tool for OSA for various populations (Nagappa et al. PLoS One. 2015;10[12]:e0143697).
The STOP-Bang Questionnaire includes four questions used in the STOP Questionnaire plus four additional demographic queries, a total of eight dichotomous (yes/no) questions related to the clinical features of sleep apnea (Snoring, Tiredness, Observed apnea, high blood Pressure, BMI, age, neck circumference, and male gender). For each question, answering “yes” scores 1, a “no” response scores 0, and the total score ranges from 0 to 8 (see www.stopbang.ca). The Questionnaire can be completed quickly and easily (usually within 1-2 minutes), and the overall response rates are typically high (90%-100%). Because of its ease of use, efficiency, and high sensitivity, the STOP-Bang Questionnaire has been widely adopted in various populations, such as sleep clinics and the surgical and general population.
The STOP-Bang Questionnaire has demonstrated a high sensitivity using a cutoff score of greater than or equal to 3: 84% in detecting any sleep apnea (apnea-hypopnea index greater than 5 events/h), 93% in detecting moderate to severe sleep apnea (AHI greater than 15 events/h), and almost 100% in detecting severe sleep apnea (AHI greater than 30 events/h). The corresponding specificities were 56.4%, 43%, and 37% (Chung et al. Anesthesiology. 2008;108[5]:812). If patients score 0-2 on the STOP-Bang Questionnaire, they are considered to be at low risk of OSA, and the possibility of moderate to severe sleep apnea can be ruled out.
The modest specificity of the STOP-Bang Questionnaire may yield moderately high false-positive cases. This may lead to unwanted sleep study referrals and increased health care expenditure. There are several ways by which the specificity can be improved, thereby decreasing false-positive rates.
Setting a threshold for the STOP-Bang scores in different population
The main advantage of the STOP-Bang scores is its flexibility to use different scores for different populations. For example, in a bariatric population, a STOP-Bang score of greater than or equal to 4 can be used. On the other hand, in an ENT population, where we would like to identify a majority of patients with moderate-severe OSA, a STOP-Bang score of greater than or equal to 5 can be used. In the sleep clinic population, as the STOP-Bang score cut-off increased from 3 to 8, the specificity increased from 52% to 100%, and the PPV increased continuously from 93% to 100% for any OSA (AHI greater than or equal to 5). A similar pattern was seen in the surgical population, as the STOP-Bang score cutoff increased from 3 to greater than or equal to 7, the specificity increased from 40% to 98%, and the PPV increased from 75% to 82% for any OSA (AHI greater than or equal to 5) (Nagappa et al. PLoS One. 2015;10[12]:e0143697).
Regional practices should decide the appropriate threshold of screening tests, after considering the implications for missed diagnoses and cost of care. There is a trade-off between sensitivity and specificity. At lower thresholds, there is improved sensitivity with potentially increased resource utilization, whereas increasing the threshold will result in loss of sensitivity and increased false-negative rates but improved resource utilization. A higher threshold should be adopted in the population with a lower prevalence of OSA.
STOP-Bang score and probability of OSA
In both sleep clinic patients (Fig 1; Panel A) and surgical patients (Fig 1; Panel B), the probability of moderate-to-severe OSA or severe OSA increased a s the STOP-Bang score increased from 3 to 7/8. With higher scores, there is a more profound increase in the probability of severe OSA, compared with moderate OSA (Chung et al. Br J Anaesth. 2012;108[5]:768).
Alternative models for scoring the STOP-Bang Questionnaire
The individual items on the Questionnaire do not share an equal predictive weight for OSA. In the “Bang” components, body mass index greater than 35 kg/m2, neck circumference greater than 40 cm, and male gender are more predictive than age greater than 50 years. The predictive performance of the specific combinations of items has been explored. Compared with the specificity of 31% for detecting moderate to severe OSA, specific combinations significantly improve the specificity to detect any OSA (AHI greater than 5), moderate to severe OSA (AHI greater than 15), and severe OSA (AHI greater than 30) at the expense of sensitivity. The specificity to detect moderate to severe OSA increases to 85% for a STOP score greater than or equal to 2 + BMI greater than 35 kg/m2; to 79% for a STOP score greater than or equal to 2 + neck circumference > greater than 40 cm (16 in); and to 77% for a STOP score greater than or equal to 2 + male, respectively. These combinations can assist in accurately identifying more patients with moderate to severe OSA (Chung et al. J Clin Sleep Med. 2014;10[9]:951).
The STOP-Bang Questionnaire and serum bicarbonate
Serum bicarbonate (HCO3–) is significantly correlated to AHI, and the addition of serum HCO3– greater than or equal to 28 mmol/L to a STOP-Bang score greater than or equal to 3 improves the specificity to predict moderate-severe OSA but decreases its sensitivity (Chung et al. Chest. 2013;143[5]:1284). For a STOP-Bang score of greater than or equal to 3 + HCO3– greater than or equal to 28 mmol/L), the specificity for detecting moderate to severe OSA increases from 30% to 82%, and from 28% to 80% for detecting severe OSA, respectively.
A two-step strategy for using STOP-Bang Questionnaire
A two-step algorithm using the STOP-Bang Questionnaire identifies patients effectively with a high probability of moderate to severe sleep apnea (Fig 2) (Chung et al. Chest. 2016;149[3]:631). The first step is to check the STOP-Bang score. If a patient scores 0-2 on the STOP-Bang Questionnaire, he or she is unlikely to have moderate to severe OSA. Conversely, a patient with a STOP-Bang score of 5-8 has a high probability of moderate to severe OSA.
The second step is for the patients with STOP-Bang scores of 3 or 4. These patients can be further classified as having a higher risk for moderate to severe OSA if one of the following conditions is met: (1) a STOP score greater than or equal to 2 + BMI greater than 35 kg/m2; (2) a STOP score greater than or equal to 2 + male gender; (3) a STOP score greater than or equal to 2 + neck circumference greater than 40 cm (16 in); or (4) a STOP-Bang score greater than or equal to 3 + serum HCO3– greater than or equal to 28 mmol/L.
The STOP-Bang Questionnaire and perioperative complications
The STOP-Bang Questionnaire not only identifies the high-risk patients with OSA but also may have a strong association toward predicting perioperative complications (Vasu et al. Arch Otolaryngol Head Neck Surg. 2010;136[10]:1020). The important step of screening patients with OSA using the STOP-Bang Questionnaire may create an awareness among the perioperative team resulting in decreased complications (Veenstra et al. Crit Care Nurs Clin N Am. 2014;26[4]:499).
The Joint Commission’s Division of Healthcare Improvement has raised strong concerns regarding the lack of training for health-care professionals to recognize OSA. A recent guideline published by the Society of Anesthesia and Sleep Medicine recommends using a screening tool to identify high-risk patients with OSA (Chung et al. Anesthesia Analgesia. 2016;June 1: Epub ahead of print).
There is preliminary evidence that patients with diagnosed OSA and a CPAP prescription had significantly reduced postoperative cardiovascular complications (cardiac arrest and shock) by more than 50% vs patients with undiagnosed OSA (Mutter et al. Anesthesiology. 2014;121[4]:707).
Conclusion
The STOP-Bang Questionnaire is a simple, practical, and flexible screening tool to identify the high-risk OSA patients. More information is available at www.stopbang.ca.
Dr. Chung is with the department of anesthesia, Toronto Western Hospital – University Health Network, University of Toronto, ON, Canada; Dr. Nagappa is with the department of anesthesia & perioperative medicine, London Health Sciences Centre and St. Joseph Health Care London, Western University, London, ON, Canada.
