Q&A Medicine>>>>>Nephrology
Question 6#

A 21-year-old college student presents to the Emergency Department with severe epigastric abdominal pain that radiates to her back. She is nauseous but has not vomited, and denies any diarrhea. She is admitted and her laboratory values show an elevated serum amylase and lipase.

Which of the following electrolyte abnormalities is associated with this disease?

A) Hypernatremia
B) Hyponatremia
C) Hyperkalemia
D) Hypokalemia
E) Hypocalcemia

Correct Answer is E

Comment:

Hypocalcemia. The first step is making the diagnosis of acute pancreatitis, which in her case is likely from alcohol. Acute pancreatitis can cause hypocalcemia due to extravascular binding of calcium to free fatty acids, which surround the pancreas as a result of pancreatic autodigestion by lipase. The other electrolyte abnormalities are not as strongly associated with acute pancreatitis as hypocalcemia. Note: One important teaching point for the interpretation of serum calcium is that the total calcium level represents both the ionized form (the physiologically active form) as well as the 45% that is bound to serum proteins (primarily albumin). Therefore, patients with low albumin will have a low total calcium but a normal ionized calcium level and will likely not have any symptoms. On the other hand, alkalosis will increase the binding affinity of albumin for calcium, causing a low ionized calcium but a normal total calcium. Bottom line: Do not be tricked by a “low” total calcium level in the setting of low albumin; you must correct for the low albumin.