Severe hyperkalemia following colon diversion surgery in a patient undergoing chronic hemodialysis: a case report

Potassium (K+) homeostasis in healthy subjects is maintained mainly by urinary excretion of K+. In patients with end-stage renal disease, the intestinal tract might assume an accessory K+ excretory role in the face of declining renal excretory function. Here, we report the case of a patient with end-stage renal disease who developed severe hyperkalemia following colon diversion surgery. A 56-year-old Caucasian woman undergoing hemodialysis experienced ischemic colitis, leading to ileocecal resection and a temporary ileostomy. She made a good recovery and her dietary intake improved. However, her pre-dialysis serum K+ level three weeks later was 7.2mmol/L, which was much higher than her previous level (range 4.9 to 6.1mmol/L). Despite dietary restriction of K+ and use of oral cation-exchange resin and low K+ dialysate, her serum K+ level remained high (6.1 to 8.3mmol/L). Six months later, her bowel continuity was restored and her serum K+ decreased to the previous level. Her fecal K+ concentration before and after stoma reversal showed a marked difference: 23mmol/L before and 60mmol/L after. We assume that the severe hyperkalemia seen in our patient was caused by reduced colonic K+ secretion due to the colon diversion. Our patient's case demonstrates the importance of colonic K+ secretion for the maintenance of K+ homeostasis in patients with end-stage renal disease.