Background: Hyperkalemia is an important issue in kidney failure. The aim of the study was to investigate the predictors of hyperkalemia in children receiving maintenance dialysis.
Methods: This was an international prospective cross-sectional observational study involving patients < 18 years receiving chronic hemodialysis or peritoneal dialysis. Hyperkalemia was defined as serum potassium (sK+) ≥ 5 mEq/L based on the Pediatric Renal Nutrition Taskforce recommendations. We recorded age, dialysis vintage, urine output (24-h urine collection); dietary K+, energy, protein and sodium intake (three-day diaries); office blood pressure (BP) in children < 5 years and 24-h ABPM in older patients; biochemistry (creatinine, urea, sodium, bicarbonate, hemoglobin, phosphate, albumin) and antihypertensive drugs.
Results: Forty-one patients were enrolled (10 peritoneal dialysis, 31 hemodialysis), median age 13.3 (IQR 10.6-15.8) years; 15 of them (36.6%) showed hyperkalemia, and median sK+ was 4.7 (4.4-5.0) mEq/L. Renin-angiotensin-aldosterone system inhibitors (RAASi) were prescribed in 9/15 patients with hyperkalemia (60%) and 7/26 (26.9%) without hyperkalemia (p = 0.04). Patients with hyperkalemia were older and had higher urea and creatinine than those with normal sK+. A backward stepwise multivariable model showed that the only predictors of hyperkalemia were age (b = 0.53, p = 0.01), urea (b = 0.02, p = 0.03) and treatment with RAASi (b = 2.75, p = 0.021).
Conclusions: While higher age, higher urea levels and treatment with RAASi independently predicted the occurrence of hyperkalemia, K+ intake was not associated with sK+ in children on dialysis. This emphasizes the importance of considering non-dietary causes of hyperkalemia and considering the bioavailability of K+ more than the total dietary K+ intake.
Keywords: Children; Dialysis; Hyperkalemia; Potassium intake; RAAS inhibitors.
© 2025. The Author(s), under exclusive licence to International Pediatric Nephrology Association.