DR ISABELLA SHUE1,2, DR ROY CHERIAN3, DR XANTHE WALKER3, DR KELLEE SLATER1, DR JAI HOFF1, DR CARMEL HAWLEY1, DR BENJAMIN LAZARUS1
1Princess Alexandra Hospital, Woolloongabba , Australia, 2Griffith University, School of Medicine and Dentistry, Southport, Australia, 3Mackay Base Hospital, Mackay, Australia
Biography:
Isabella is currently a Junior House Officer at the Princess Alexandra Hospital in Brisbane. She is preparing for Basic Physician Training with a keen interest in Nephrology.
Background:
The kidneys are responsible for regulating total body potassium, accounting for approximately 90% of potassium excretion with the remainder excreted by the colon. In kidney failure, upregulation of colonic potassium secretion has been identified as an important compensatory mechanism in maintaining potassium balance as kidney function declines.
Case Report:
We present an under-recognised case of refractory hyperkalaemia following ileostomy and loop colonic fistula creation in a 54-year-old female with end-stage kidney failure secondary to focal segmental glomerulosclerosis on chronic haemodialysis. In the months following ileostomy creation, serum potassium levels ranged from 6.9 to 8.9 mmol/L despite daily administration of 15 g sodium polystyrene sulfate, strict adherence to a low potassium diet confirmed on dietitian review, and adequate haemodialysis with a urea reduction ratio of 76% without evidence of recirculation. The nature of the patient’s bowel anatomy made it possible to administer 30 g sodium polystyrene sulfonate through the distal limb of the ileostomy, which allowed for substrate movement into the proximal defunctioned colon. This was effective in maintaining normokalaemia during the preoperative period.
Hyperkalaemia resolved following definitive stoma reversal. Furthermore, there was marked increase of faecal potassium concentration from 8 mmol/L pre-stoma reversal to 53 mmol/L at 3 months post-stoma reversal. These findings support the concept of refractory hyperkalaemia attributable to decreased colonic potassium secretion in the setting of ileostomy and associated diversion of bowel contents.
Conclusion:
This case highlights the significance of colonic potassium secretion in maintaining potassium homeostasis in patients receiving haemodialysis. Bowel diversion surgery should be considered as a potential contributing factor to refractory hyperkalaemia in patients receiving maintenance haemodialysis.