Deep Versus Moderate Hypothermia in Pediatric Cardiac Surgery: Systematic Review and Meta-Analysis of Early Postoperative Outcomes.

IntroductionDeep hypothermia (DH) has been widely adopted for cerebral and visceral protection during pediatric cardiac surgery, but concerns about perioperative complications remain. This meta-analysis aims to evaluate the impact of DH compared to moderate hypothermia (MH) on outcomes in pediatric cardiac surgery patients.MethodsFollowing a PRISMA-compliant systematic search in PubMed, Cochrane, and Embase, eligible studies comparing DH (<22°C) with MH (22-30°C) in pediatric cardiac surgery were assessed. Risk of bias was evaluated using the ROBINS-I tool.ResultsFive comparative studies with 448 patients (250 in the MH group and 198 in the DH group) were included. Baseline characteristics were similar between groups, with the majority of patients undergoing aortic arch repairs. Perioperative variables were also similar, except for cross-clamp time, which was significantly longer in the DH group (p = 0.02), and circulatory arrest was more frequently used in DH patients (p = 0.01). No significant differences were found in overall postoperative complication rates, acute kidney injury, 24-h chest drainage volume, or in-hospital mortality. However, the incidence of early postoperative neurological complications was significantly higher in the DH group (p < 0.001).ConclusionsModerate hypothermia may be associated with a significantly lower incidence of postoperative neurological complications compared to deep hypothermia, while overall in-hospital mortality and morbidity rates remained similar between the two groups. Taken together, these findings support moderate hypothermia with regional perfusion as a clinically feasible and well-tolerated alternative to deep hypothermia in pediatric cardiac surgery.