Severe Hypomagnesemia Induced by Postoperative Zinc Supplementation: An Illustrative Demonstration of Electrolyte Homeostasis.

Abstract

Background: Managing electrolyte abnormalities is one of the cornerstones of properly caring for and managing hospitalized patients. Typically, electrolyte derangements are managed by direct repletion, volume status correction, or hemodialysis; however, the persistence of electrolyte abnormalities despite utilizing appropriate initial strategies requires further investigation.

Case description: A 72-year-old male presented to the emergency department with weakness 2 months post-exploratory laparotomy with ileostomy for small bowel perforation complicated by intra-abdominal infection. The patient was treated for sepsis and imaging revealed intra-abdominal and abdominal wall abscesses. After drainage, recovery was complicated by treatment of refractory hypomagnesemia in the context of zinc supplementation.

Discussion: If initial electrolyte repletion measures do not provide the intended benefit, investigating secondary causes of refractory electrolyte abnormalities is necessary. While hypomagnesemia is one of the least common electrolyte derangements seen within the general acute care hospital setting, in facilities with relatively high volumes of bariatric or gastrointestinal surgical patients, keeping the phenomenon of zinc-induced hypomagnesemia in mind becomes more crucial due to its frequent use in those settings.

Conclusion: This case highlights the effects of excess high-dose zinc supplementation in a patient without zinc deficiency in the postoperative period who developed treatment-resistant hypomagnesemia due to zinc-induced impairment of magnesium absorption as well as gastrointestinal and renal losses.

Learning points: Zinc supplementation can cause hypomagnesemia.