User login
In Reply: Generally, it is preferable to measure the ionized calcium directly, particularly if there is uncertainty about whether the corrected serum calcium is reflective of the ionized calcium, if the patient’s symptoms are atypical, or if a reliable laboratory is available to measure ionized calcium.
Direct measurement of the ionized calcium concentration could be favored compared with measuring the corrected calcium in patients with symptoms of hypocalcemia in the setting of a normal total calcium concentration. Symptomatic hypocalcemia with normal total calcium but low ionized calcium can occasionally occur in patients with acute respiratory alkalosis due to increased binding of calcium to albumin. Thus, respiratory alkalosis may cause an acute decrease in ionized calcium. Furthermore, the ionized fraction can change without an alteration in the total serum calcium concentration, as with hyperparathyroidism, which increases the ionized calcium at the expense of that bound to albumin, and hyperphosphatemia, which increases the fraction bound to inorganic anions, decreasing ionized calcium. In patients who have chronic kidney disease and a low serum bicarbonate or a low serum albumin, or both, measuring the ionized calcium is preferable to measuring the total calcium in order to diagnose hypocalcemia or hypercalcemia.
The patient was given oral magnesium, potassium, calcium, and vitamin D to continue at home. In addition, she was advised to avoid excessive alcohol consumption, and she was followed by her primary care doctor. All the laboratory values normalized within 1 month of abstinence from alcohol, and she has been well since. We agree regarding the importance of checking on the ionized calcium to confirm the hypocalcemia and normalization after treatment as stated above. Ionized calcium was never checked during the hospital stay or during the follow-up after the discharge.
In Reply: Generally, it is preferable to measure the ionized calcium directly, particularly if there is uncertainty about whether the corrected serum calcium is reflective of the ionized calcium, if the patient’s symptoms are atypical, or if a reliable laboratory is available to measure ionized calcium.
Direct measurement of the ionized calcium concentration could be favored compared with measuring the corrected calcium in patients with symptoms of hypocalcemia in the setting of a normal total calcium concentration. Symptomatic hypocalcemia with normal total calcium but low ionized calcium can occasionally occur in patients with acute respiratory alkalosis due to increased binding of calcium to albumin. Thus, respiratory alkalosis may cause an acute decrease in ionized calcium. Furthermore, the ionized fraction can change without an alteration in the total serum calcium concentration, as with hyperparathyroidism, which increases the ionized calcium at the expense of that bound to albumin, and hyperphosphatemia, which increases the fraction bound to inorganic anions, decreasing ionized calcium. In patients who have chronic kidney disease and a low serum bicarbonate or a low serum albumin, or both, measuring the ionized calcium is preferable to measuring the total calcium in order to diagnose hypocalcemia or hypercalcemia.
The patient was given oral magnesium, potassium, calcium, and vitamin D to continue at home. In addition, she was advised to avoid excessive alcohol consumption, and she was followed by her primary care doctor. All the laboratory values normalized within 1 month of abstinence from alcohol, and she has been well since. We agree regarding the importance of checking on the ionized calcium to confirm the hypocalcemia and normalization after treatment as stated above. Ionized calcium was never checked during the hospital stay or during the follow-up after the discharge.
In Reply: Generally, it is preferable to measure the ionized calcium directly, particularly if there is uncertainty about whether the corrected serum calcium is reflective of the ionized calcium, if the patient’s symptoms are atypical, or if a reliable laboratory is available to measure ionized calcium.
Direct measurement of the ionized calcium concentration could be favored compared with measuring the corrected calcium in patients with symptoms of hypocalcemia in the setting of a normal total calcium concentration. Symptomatic hypocalcemia with normal total calcium but low ionized calcium can occasionally occur in patients with acute respiratory alkalosis due to increased binding of calcium to albumin. Thus, respiratory alkalosis may cause an acute decrease in ionized calcium. Furthermore, the ionized fraction can change without an alteration in the total serum calcium concentration, as with hyperparathyroidism, which increases the ionized calcium at the expense of that bound to albumin, and hyperphosphatemia, which increases the fraction bound to inorganic anions, decreasing ionized calcium. In patients who have chronic kidney disease and a low serum bicarbonate or a low serum albumin, or both, measuring the ionized calcium is preferable to measuring the total calcium in order to diagnose hypocalcemia or hypercalcemia.
The patient was given oral magnesium, potassium, calcium, and vitamin D to continue at home. In addition, she was advised to avoid excessive alcohol consumption, and she was followed by her primary care doctor. All the laboratory values normalized within 1 month of abstinence from alcohol, and she has been well since. We agree regarding the importance of checking on the ionized calcium to confirm the hypocalcemia and normalization after treatment as stated above. Ionized calcium was never checked during the hospital stay or during the follow-up after the discharge.