#5623 PERITONEAL DIALYSIS AND POSTOPERATIVE OUTCOMES IN CHILDREN AFTER CARDIAC SURGERY: A SINGLE-CENTER COHORT STUDY
Authors: Pimenta Gonçalo , Afonso Rita , Vida Ana Carlota , Calça Rita , Graça Isabel , Estevens Maria , Matias Patrícia , Anjos Rui , Branco Patricia 
Published: June 2023

Abstract

Background and Aims
Acute kidney injury (AKI) is a frequent complication in neonates and infants after congenital heart disease surgery, with great impact on morbidity and mortality. Peritoneal dialysis (PD) is the renal replacement therapy of choice, as it allows continuous gentle ultrafiltration with minimal impact on hemodynamic status. However, there is no standardized prescription. The present study aimed to describe our experience of using PD in the management of AKI after cardiac surgery in pediatric patients and the postoperative outcomes.

Method
Single-center cross-sectional study including 21 children undergoing cardiac surgery between 2017 and 2022, in a congenital heart disease reference center. Demographic and clinical data were collected from the electronic records.

Results
Of the 21 patients treated with PD, 11 were female. Mean age was 32 ± 45 days and median weight was 3.4 kg (IQR 0.5). All pregnancies had been full-term with a mean birth weight of 3.2 ± 0.3 kg. No congenital urinary tract anomalies had been previously documented. Previous history of AKI was present in 2 patients. Transposition of the great arteries was the most common surgical indication (52%). RACHS-1 score was ≥4 in 12 patients and median PRISM-IV score was 6.5% (IQR 6). Cardiopulmonary bypass was performed in 19 patients with a mean time of 181 ± 72 minutes and a mean aortic clamping time of 94 ± 29 minutes. All patients required inotropic support after cardiac surgery with ≥2 drugs, for 197 ± 136 hours. Median time with mechanical ventilation support was 126 hours (IQR 288) and median length of stay at the intensive care unit (ICU) was 9 days (IQR 15.3).The indications for PD initiation were anuria (66.7%), oliguria (23.8%) and fluid overload (9.5%). Median time between cardiac surgery and AKI diagnosis was 2.5 hours (IQR 8.8) and between AKI diagnosis and PD initiation was 1.8 hours (IQR 4.3). Median duration under dialysis was 2 days (IQR 3.5). Exchange volume of dialysate varied between 6 and 15 mL/kg at the beginning of PD. In 11 patients, this volume was progressively increased to a maximum of 60 mL/kg (minimum: 30 mL; maximum: 120 mL). Continuous veno-venous hemodiafiltration was required in 3 patients, mainly due to mechanical catheter dysfunction. Complications related to PD occurred in 5 patients: 1 patient developed peritonitis, 1 patient had mechanical catheter dysfunction and 3 patients had peri-catheter leak. Complete recovery of renal function was achieved in 14 patients. Longer time on PD was associated with lower weight before surgery (p = 0.04), longer time on mechanical ventilation and inotropic support (p &lt; 0.001), and longer stay at the ICU (p &lt; 0.001). Time on inotropic support could predict time on PD using a multiple regression model (adjusted R2 = 59%, p = 0.003), adjusted to cardiopulmonary bypass time, time on mechanical ventilation support and weight before surgery (adjusted ß = 0.7, p = 0.005). Eight patients died during hospitalization, due to multiorgan failure (38%), cardiogenic shock (38%), disseminated intravascular coagulation (13%) and septic shock (13%). Longer cardiopulmonary bypass time was associated with in-hospital mortality (149 ± 53 vs 235 ± 46, p = 0.004). Both the time between AKI diagnosis and PD initiation and the time on PD were not associated with in-hospital mortality.

Conclusion
Our study suggests that PD is a safe and effective dialysis modality in the management of post-cardiac surgery AKI in pediatric population. Early identification of high-risk infants is important to implement preventive measures.