Chronic Kidney Disease Is a Risk Factor for the Development of Hyperchloremic Metabolic Acidosis After Repeated Therapeutic Plasma Exchanges

Hyperchloremic metabolic acidosis is an underreported but common metabolic complication following therapeutic plasma exchange (TPE) with an albumin-saline solution, particularly when multiple TPE sessions are performed within a limited period. The risk of hyperchloremic metabolic acidosis may be the highest in patients with chronic kidney disease because of their limited acid excretion capacity. We prospectively collected data from all patients who received TPE at Amsterdam UMC between February 2023 and March 2025. We collected data on demographics, TPE-related parameters, and blood electrolyte concentrations. We investigated the effect of TPE on plasma sodium, chloride, and bicarbonate concentrations, the occurrence of adverse events, and the modulating role of kidney function. Data from 64 patients with 320 TPE sessions were included in the analysis. The mean age was 50 years, 55% of the patients were male and the mean eGFR was 35 mL/min/1.73 m². The effect of a single TPE on plasma electrolyte concentration was independent of kidney function. However, after multiple TPE sessions, a lower eGFR was associated with a greater increase in plasma chloride concentration (p < 0.001) and a larger decrease in plasma bicarbonate concentration (p < 0.001) despite oral bicarbonate supplementation and a lower baseline plasma bicarbonate concentration. Patients with a lower eGFR were more likely to experience adverse events during a TPE session (p = 0.004). Chronic kidney disease is a risk factor for developing hyperchloremic metabolic acidosis and adverse events during an intensive TPE cycle.