Review Article   

Minerva Anestesiologica 2022 Mar 23

DOI: 10.23736/S0375-9393.22.16449-7

Copyright © 2022 EDIZIONI MINERVA MEDICA

lingua: Inglese

The effects of exposure to severe hyperoxemia on neurological outcome and mortality after cardiac arrest

Luigi LA VIA ^{1, 2} ✉, Marinella ASTUTO ^{1, 2}, Elena G. BIGNAMI ³, Diana BUSALACCHI ², Veronica DEZIO ^{1, 2}, Massimo GIRARDIS ⁴, Bruno LANZAFAME ^{1, 2}, Giuseppe RISTAGNO ⁵, Paolo PELOSI ^{6, 7}, Filippo SANFILIPPO ¹

¹ Department of Anaesthesia and Intensive Care, Policlinico-Vittorio Emanuele University Hospital, Catania, Italy; ² School of Anaesthesia and Intensive Care, University Hospital G. Rodolico, University of Catania, Catania, Italy; ³ Anesthesiology, Critical Care and Pain Medicine Division, Department of Medicine and Surgery, University of Parma, Parma, Italy; ⁴ Department of Anesthesia and Intensive Care, University Hospital of Modena, Modena, Italy; ⁵ Department of Anesthesiology, Intensive Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy; ⁶ Anesthesia and Intensive Care, Ospedale Policlinico San Martino, IRCCS for Oncology and Neurosciences, Genoa, Italy; ⁷ Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy

INTRODUCTION: Hyperoxemia during cardiac arrest may increase chances of successful resuscitation. However, episodes of severe hyperoxemia after intensive care unit admission occurs frequently (up to 60%), and these have been associated with higher mortality in cardiac arrest patients. The impact of severe hyperoxemia on neurological outcome is more unclear.
EVIDENCE ACQUISITION: We conducted a systematic review and meta-analysis on Pubmed and EMBASE to evaluate the effects of severe hyperoxemia according to arterial blood gas analysis on neurological outcome and mortality in patients resuscitated from cardiac arrest and admitted to intensive care unit.
EVIDENCE SYNTHESIS: Thirteen observational studies were included, eight of them reporting data on neurological outcome and ten on mortality. Most studies reported odds ratio adjusted for confounders. Severe hyperoxemia was associated with worse neurological outcome (OR 1.37 [95%CI 1.01,1.86], p=0.04) and higher mortality at longest follow-up (OR 1.32 [95%CI 1.11,1.57], p=0.002). Subgroup analyses according to timing of hyperoxemia showed that any hyperoxemia during the first 36 hours was associated with worse neurological outcome (OR 1.52 [95%CI 1.12,2.08], p=0.008) and higher mortality (OR 1.40 [95%CI 1.18,1.66], p=0.0001), whilst early hyperoxemia was not (neurological: p=0.29; mortality: p=0.19). Sensitivity analyses mostly confirmed the results of the primary analyses.
CONCLUSIONS: Severe hyperoxemia is associated with worse neurological outcome and lower survival in cardiac arrest survivors admitted to intensive care unit. Clinical efforts should be made to avoid severe hyperoxemia during at least the first 36 hours after cardiac arrest.

KEY WORDS: Normoxia; Intensive care; Resuscitation; Return of spontaneous circulation; Hypoxia; Brain injury; Cerebral performance category; Mortality