Comparison of Serum Phosphate Levels in Critically Ill Patients with Acute Kidney Injury Undergoing Continuous Renal Replacement Therapy Using Different Dialysates.

Introduction: Continuous renal replacement therapy (CRRT) is a recommended dialysis modality for hemodynamically unstable and critically ill patients with kidney failure. This study aimed to evaluate the effect of variations in serum phosphate levels based on the dialysate used during CRRT and to determine the impact of prognosis and mortality of patients with using dialysate solutions with diverse electrolyte compositions.

Methods: We retrospectively analyzed 117 patients' records, treated with intensive CRRT, comprising 70 patients treated with Phoxilium®, and 47 patients treated with MultiBic®.

Results: After 72 hours of CRRT, the Phoxilium and non-Phoxilium groups exhibited significantly different serum calcium, bicarbonate, and phosphate levels, as determined by an independent-samples t-test. (P < .05). The Kaplan-Meier analysis revealed no significant difference in survival rates between the two groups, demonstrating that the variation in serum phosphate level after 72h of CRRT did not significantly influence survival outcomes. (P = .581). The difference in serum phosphate levels after 72h of CRRT might affect respiratory muscles; however, although cumulative survival exhibited a stepwise decrease with longer mechanical ventilation duration, the two groups did not show significant difference in survival (P = .819). The incidence of hypophosphatemia was significantly lower in the group where CRRT was performed with Phoxilium dialysate containing phosphate compared to the group where CRRT was performed with non-Phoxilium dialysate, and severe hypophosphatemia did not occur. There were no significant associations between hypophosphatemia, mortality, and duration of mechanical ventilation.

Conclusion: Selecting Phoxilium as a dialysate for CRRT should be considered to correct severe hypophosphatemia, prevent complications, and improve prognosis.