Sodium Polysterone Sulfonate-Induced Colonic Mucosal Necrosis in a Hypovolemic Patient With Acute Kidney Injury

Abstract

Introduction: Sodium polystyrene sulfonate (SPS, Kayexalate®), an ion-exchange resin used in treating hyperkalemia, removes potassium by exchanging sodium ions for potassium ions in the intestine (especially the large intestine) before the resin is passed from the body. Although rare, intestinal necrosis (including fatalities) and other serious gastrointestinal events (e.g., bleeding, ischemic colitis, perforation) have been reported, especially when administered with sorbitol. Here, we present a patient with Kayexalate®-induced colonic necrosis in a hypovolemic patient with acute kidney injury (AKI). Case Report: An 80-year-old white male presented with multiple episodes of diarrhea, hypotension, and AKI (Cr 3.7). Physical examination was remarkable for generalized abdominal discomfort. Initial labs showed potassium of 5.7 for which he received a dose of Kayexalate® 30 grams orally. The following day, he continued to have diarrhea and developed abdominal distention. Due to his clinical deterioration, a CT abdomen pelvis was done, which showed colitis of the sigmoid colon and rectum. Temporary hemodialysis was initiated for electrolyte abnormalities in the setting of worsening renal function. He then began having hematochezia, prompting a colonoscopy, which revealed severe welldemarcated colitis in the rectosigmoid junction with a large amount of blood clots at the demarcation. In the next couple of days, his abdominal pain and distension significantly worsened, and an emergent exploratory laparotomy was performed. The sigmoid colon and rectum appeared to be very thickened and dilated with fibrinous debris on the serosal surfaces. Due to the amount of distension of the entire colon, a subtotal colectomy with an end ileostomy was performed. He recovered well postoperatively. His pathology report showed distal rectosigmoid ischemic colitis, with mucosal and focal submucosal necrosis and crystals consistent with Kayexelate®. Conclusion: SPS, particularly when used with sorbitol, has been associated with cases of intestinal necrosis and other serious GI adverse events. Due to the concern that sorbitol may increase the risk of intestinal necrosis, concomitant use of sorbitol is no longer recommended. Increased risk may be associated with a history of intestinal disease or surgery, hypovolemia, prematurity, and renal insufficiency or failure. Avoid Kayexalate® use in any postoperative patient until normal bowel function resumes or in patients at risk for constipation or impaction; discontinue use if constipation occurs. Also, in patients who received Kayexalate’, clinicians must keep a close watch on any gastrointestinal symptoms to prevent catastrophic complications.