1595 Kayexalate-Induced Colitis: A Rare Cause of Acute Abdomen!

Abstract

INTRODUCTION: Sodium polystyrene sulfonate (kayexalate) combined with sorbitol is a resin that exchanges sodium for potassium primarily in the colonic mucosa to treat hyperkalemia. It has been associated with ischemic colitis. CASE DESCRIPTION/METHODS: We present a case of a 78-year-old female with a medical history of renal disease requiring hemodialysis and heart failure, admitted with an ischemic right lower limb. She was started on an intravenous heparin drip as per vascular surgery recommendations. Overnight her potassium level was noted to be 5.9 mg/dL for which she was medically treated with dextrose solution, regular insulin along with three doses of oral 15 mg kayexalate. The next morning she complained of sudden onset abdominal pain. CT imaging showed pneumatosis along with asymmetric mural thickening of the cecum, concerning for cecal ischemia. The patient underwent emergent exploratory laparotomy which revealed ischemia of the cecum and ascending colon. A right hemicolectomy was done and the patient eventually made a complete recovery. Later, pathology revealed findings of ischemic colitis with detached purple refractile material in the colon consistent with kayexalate crystals. DISCUSSION: Colonic necrosis after the use of kayexalate is a rare and an under-recognized complication. Incidence of colonic necrosis is reported to be around 0.27% which increases to 1.8% in uremic patients. It often presents with nonspecific symptoms such as constipation, fecal impaction, obstruction, gastrointestinal bleeding, bezoars and rarely, acute abdomen as in our patient. Previously addition of sorbitol to kayexalate was thought to be the main culprit leading to colonic necrosis but cases have been reported in patients taking sorbitol free kayexalate. The exact mechanism of action remains unclear with a few possibilities such as a direct toxic effect, elevated prostaglandin levels and hyperreninemia in patients with renal insufficiency, leading to nonocclusive mesenteric ischemia, have been suggested. Endoscopically it presents as ulcerated lesions with a definitive diagnosis made after seeing kayexalate crystals on the histological exam. Patients without signs of peritonitis are usually managed medically with intravenous fluid resuscitation, use of supplemental oxygen, bowel rest and broad-spectrum antibiotics. Clinicians must be cautious in prescribing kayexalate to patients and keep kayexalate induced colitis in one of the differentials in patients presenting with signs and symptoms of colitis.