Early Peritoneal Dialysis Following Cardiac Surgery Is Associated with Severe AKI at Postoperative 48 Hours

Background: Association between early peritoneal dialysis (PD) start and favorable fluid balance is reported for newborns and young infants following cardiac surgery. This retrospective study compares the outcomes of two post-operative strategies for newborns, intra-operative PD catheter placement and early start of PD versus medical management with diuretics. Methods: During the “Early PD” era (2012-2015), PD catheter was placed for the high-risk newborns in the operating room following cardiopulmonary bypass (CPB). Those newborns who did not achieve negative fluid balance in the first post-operative 24 hours were started on PD. During the “Diuretic” era (2016-2019), newborns were treated with diuretics during post-operative period. Baseline demographic, laboratory and outcome data were compared for the first post-operative five days. The primary outcome was acute kidney injury (AKI) at post-operative 48 hours. The secondary outcomes included AKI at post-operative 5 days and 5% fluid overload at 48 hours. Results: The Early PD era was 49 newborns and the Diuretic era was 52 newborns. The baseline demographic and laboratory data were similar between the eras. During the Early PD era, 29 newborns were started on PD and for the remaining 20 PD catheters were used as drains. The Diuretic era newborns did not require PD for 48 of the cases and 4 required PD after the study period. During multinomial logistic regression, the Diuretic era newborns developed less severe AKI (OR=0.32, p value= 0.041) at post-operative 48 hours. Increasing duration of CPB predicted severe AKI (OR=1.21, p value=0.044). The Diuretic era newborns were more likely to develop 5% fluid overload at 48 hours (OR= 3.61, p value=0.059). There was no difference between the two groups for developing severe AKI at post-operative 5 days (OR= 0.20, p value=0.063). The CPB durations were similar when the two eras were compared using simple linear regression (beta= -0.87, p=0.11). Conclusion: The newborns during the Diuretic era developed less severe AKI at post-operative 48 hours and were more likely to have 5% fluid overload. Early PD use may be associated with more frequent AKI for newborns. This preliminary finding should be investigated in prospective, randomized protocols.