No predialysis treatment of blood primes in pediatric continuous kidney replacement therapy

Abstract

BackgroundPediatric continuous kidney replacement therapy (CKRT) uses blood as the priming fluid in the CKRT circuit to prevent hemodilution and hypotension and is dialyzed using a dialysate before the start of CKRT. This study aimed to investigate the safety of CKRT using a protocol of no predialysis after blood priming in underweight infants, based on hemodynamic and laboratory data changes.MethodsThis single-center retrospective cohort study included children weighing < 5 kg after cardiac surgery treated with CKRT from March 2019 to February 2022. Our protocol is as follows. We used 6-Fr vascular access, 20 mL priming volume of 0.3 m2 cellulose triacetate membrane, 37 mL priming volume of the pediatric extracorporeal circuit, and 57 mL of total extracorporeal volume. Heparin saline was prefilled with the extracorporeal circuit, and then, 30 mL of packed red blood cells was used to prime. Subsequently, the therapy was started without predialysis treatment of blood primes and vasopressin was used as a vasopressor for hypotension. Hemodynamic and laboratory data changes were studied.ResultsCKRT was performed in 8 patients, and 19 circuit connections were analyzed. Hypotension was observed in 10/19 (52.6%) connections, but all patients recovered within approximately 10 min. Ionized calcium, bicarbonate, and pH values were significantly decreased (p = 0.001, < 0.001, and < 0.001, respectively) before dialysis. However, 60 min after dialysis, pH recovered to predialysis levels and ionized calcium and bicarbonate recovered to > 95% of the levels before extracorporeal circulation. Moreover, potassium levels, which were not significantly different between extracorporeal circulation and dialysis initiation (p = 1.000), were significantly decreased after dialysis (p = 0.046). Lactate and hematocrit did not significantly change either before dialysis (p = 0.131 and 0.071, respectively) or after dialysis compared to the time of extracorporeal circulation (p = 1.000 and 0.591, respectively).ConclusionsCKRT, using our protocol, could be safely performed without predialysis treatment of blood primes in children weighing < 5 kg.