A Nomogram to Identify Hyperkalemia Risk in Patients with Advanced CKD

Abstract

Background: Hyperkalemia is a common and life-threatening complication of chronic kidney disease (CKD). We aimed to develop and validate a nomogram that could identify the risk of hyperkalemia (≥ 5.5 mmol/L) in CKD patients. Methods: A retrospective cohort study was performed in adult patients with pre-dialysis advanced CKD (stages ≥ 3) in 2020-2021 for the outcome of hyperkalemia within 6 months. The training set was used to identify risk factors of hyperkalemia. Then a nomogram was developed by multivariable logistic regression analysis. C-statistics, calibration curves, and decision curve analysis (DCA) were used, and the model was validated in the internal and two external validation sets. Results: 847 advanced CKD patients were included. In 6 months, 27.6% of patients had hyperkalemia (234/847). Independent risk factors were: age ≥ 75 years, higher CKD stages, previous event of serum potassium ≥ 5.0 mmol/L within 3 months, and comorbidities with heart failure, diabetes, or metabolic acidosis. Then the nomogram based on the risk factors adding the use of renin-angiotensin-aldosterone system inhibitors was constructed. The C-statistic of the model was 0.757 (95% CI 0.698-0.783), and was stable in both the internal validation set (0.732, 95% CI 0.632-0.818) and external validation sets (0.878, 95% CI 0.843-0.950 and 0.817, 95% CI 0.718-0.915). Calibration curves and DCA analysis both found good performances of the nomogram. Conclusion: A feasible nomogram and online calculator were developed and validated to evaluate the risk of hyperkalemia within 6 months in advanced CKD patients. CKD patients with a high risk of hyperkalemia may benefit from intensive monitoring and early triage.