Optimal oxygen use in neonatal advanced cardiopulmonary resuscitation-a literature review.

Abstract

Background and objectives: Oxygen (O₂) use during neonatal cardiopulmonary resuscitation (CPR) remains a subject of controversy. The inspired O₂ concentration during neonatal CPR, that hastens return of spontaneous circulation (ROSC), allows adequate cerebral and myocardial O₂ delivery, and enhances survival to discharge, is not known. The optimal FiO₂ during CPR should decrease incidence of hypoxia but also avoid hyperoxia, and ultimately lead to improved neurodevelopmental outcomes. Due to infrequent need for extensive resuscitation, and emergent circumstances surrounding neonatal CPR, conducting randomized clinical trials continues to be a challenge. The goal of this study was to review the evolution of oxygen use during neonatal CPR, the evidence from animal and clinical studies on oxygen use during neonatal CPR and after ROSC, the pertinent physiology including myocardial oxygen consumption and cerebral oxygen delivery during CPR, and outcomes following CPR in the DR and in the neonatal intensive care unit.

Methods: This narrative review is based on recent and historic English literature in PubMed and Google scholar over the past 35 years (January 1, 1985 - May 1, 2021).

Key content and findings: Several studies in animal models have compared ventilation with different inspired O₂ concentrations (mostly 21% and 100%) during chest compressions and after ROSC. These studies reported no difference in short-term outcomes, even with as low as 18% O₂. However, in lamb models of cardiac arrest and CPR, 100% O₂ during chest compressions is associated with better oxygen delivery to the brain compared to 21% O₂. Abrupt weaning to 21% O₂ following ROSC followed by titration to achieve preductal SpO₂ of 85-95% minimizes systemic hyperoxia and oxidative stress compared to slow weaning from 100% O₂ following ROSC.

Conclusions: Clinical research is needed to arrive at the best strategy for assessment of oxygenation and choice of FiO₂ during neonatal CPR that lead to improved survival and outcomes. In this article, we have reviewed the literature on evidence behind O₂ use during neonatal advanced CPR and after ROSC.