Analysis of risk factors of central nervous system complications supported on extracorporeal membrane oxygenation

Abstract

Objective: To investigate the risk factors of central nervous system (CNS) complications in children undergoing extracorporeal membrane oxygenation (ECMO) support. Methods: The clinical data, ECMO parameters, laboratory examination and outcome (follow-up to 90 d after discharge) of 82 children treated with ECMO in the pediatric intensive care unit (PICU) of Shanghai Children's Hospital from December 2015 to December 2021 were analyzed retrospectively in this study. The patients were divided into CNS complication group and non-CNS complication group. The ECMO mode, ECMO catheterization mode, clinical and laboratory indicators pre-ECMO and 24 h after ECMO initiation, in-hospital mortality and 90-day mortality were compared with Chi-square test, t test and nonparametric rank sum test. Kaplan-Meier method was used to draw survival curve, and Log-rank test was used to compare the difference in survival rate. The receiver operating characteristic (ROC) curve was used to evaluate the power of variables to predict CNS complications. Results: A total of 82 children were treated with ECMO, including 49 males and 33 females, aged 34 (8, 80) months. There were 18 cases suffering CNS complications, including cerebral hemorrhage in 8 cases, epilepsy in 6 cases, simple cerebral infarction in 3 cases, and cerebral hemorrhage combined with cerebral infarction in 1 case. Veno-arterial ECMO accounted for a greater proportion in CNS complication group (17/18 vs. 67% (43/64), χ2=4.02, P=0.045). A higher percentage of children with CNS complications underwent surgical cannulation compared to those in non-CNS complication group (16/18 vs. 53% (34/64), χ2=7.55, P=0.006). The laboratory results indicated that lower pre-ECMO pH value (7.24 (7.15, 7.28) vs. 7.35 (7.26, 7.45), Z=-3.65, P<0.001) and platelet count 24 h after ECMO initiation (66 (27, 135) ×109/L vs. 107 (61, 157) ×109/L, Z=-2.04, P=0.041) were associated with CNS complications. In the CNS complication group, 7 children died during hospitalization and 7 died during 90-day after admission, and there was no significant difference compared with those in the non-CNS complication group (7/18 vs. 31% (20/64), 7/18 vs. 34% (22/64), both P>0.05). The ROC curve analysis indicated that the area under the ROC curve for pre-ECMO pH value was 0.738 (95%CI 0.598-0.877), and the optimal cut-off value was 7.325. Conclusions: CNS complications in children undergoing ECMO support are common. Pre-ECMO pH value <7.325 is a risk factor for CNS complications. Reducing the veno-arterial ECMO and surgical cannulation can help reduce the occurrence of CNS complications.