Intestinal necrosis due to sodium polystyrene (Kayexalate) in sorbitol enemas: clinical and experimental support for the hypothesis.

Five patients who suffered catastrophic colonic necrosis are presented. All patients were uremic and received sodium polystyrene (Kayexalate) in sorbitol enemas for the treatment of hyperkalemia shortly before the development of signs and symptoms of colonic necrosis. In all specimens extensive ischemic necrosis was present, and Kayexalate crystals were noted in the intestinal lumen. Four of the five patients eventually died. To further investigate the occurrence of colonic necrosis after the administration of Kayexalate in sorbitol enemas, a series of experiments were performed in rats. Two groups of Sprague-Dawley rats were studied. One group was made uremic by performance of bilateral nephrectomy. The other group underwent sham operation. Enemas of saline, Kayexalate alone, sorbitol alone, or Kayexalate in sorbitol were administered. In nonuremic rats, transmural necrosis was noted in seven of 10 rats receiving sorbitol enemas and in six of 10 rats receiving Kayexalate in sorbitol enemas. No significant pathologic changes were noted in the rats receiving other enemas. In uremic rats, extensive transmural necrosis was noted in all rats receiving enemas of sorbitol or Kayexalate in sorbitol. All of these 19 rats died within the period of observation compared with no deaths in 18 rats that received enemas without sorbitol (p less than 0.001).