Cardiovascular Hemodynamics of Hypoxic Neonates During Therapeutic Hypothermia and the Warming Phase: A Literature Review

This study aimed to evaluate the effects of therapeutic hypothermia (TH) and the warming phase on cardiovascular hemodynamics among neonates suffering from perinatal asphyxia. The reviewed literature on hemodynamic changes among neonates undergoing TH was obtained from the following databases: PubMed, Embase, POPLINE, Cochrane Reference Libraries, Google Scholar, Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews. Search strategies included keywords, combinations, medical subject headings, and snowball searches of related articles. The following search terms were used: brain injury, hypoxic-ischemic encephalopathy, left ventricular (LV) dysfunction, right ventricular (RV) dysfunction, and TH. We selected publications evaluating RV and LV heart function and cerebral, renal, and visceral circulation function for analysis. There were 12 prospective studies, with a total of 361 patients in the study groups and 149 patients in the control groups. There were seven retrospective studies, with a total of 1637 patients. One study was a randomized controlled trial, one was a systematic review, and one was a Cochrane review. The limitations of the review are that most of the studies are observational, making it difficult to precisely assess the causes of the observed changes, whether they are related to asphyxia, hypothermia, or other pathology. The results of the observational studies were not consistent with those of the randomized trials for ethical reasons. The hemodynamic characteristics of the cardiovascular system during TH and the rewarming phase are significantly complex. Therefore, an in-depth understanding of the pathophysiological attributes associated with these aspects is essential to provide individualized therapeutic approaches for optimizing cerebral perfusion pressure and reducing secondary injuries.