Treatment with normobaric or hyperbaric oxygen and its effect on neuropsychometric dysfunction after carbon monoxide poisoning

AbstractBackground: Carbon monoxide (CO) poisoning may result in acute neurological sequelae, cognitive sequelae, and delay neurologicalsequelae. The administration of hyperbaric oxygen (HBO) to prevent the development of delayed neurological sequelae in CO poisoning have extensively investigated but conflicting results have been reported. We performed a systematic literature review and meta-analysis of randomized controlled trials (RCTs) evaluating HBO treatment and its effect on neuropsychometric dysfunction after CO poisoning.Methods: We searched Medline, Embase, Pubmed, and the Cochrane Register of Controlled Trials from inception to December2017. Eligible studies compared HBO therapy with normobaric oxygen (NBO) in patients with CO poisoning.Results: Six studies comparedHBOwithNBO inCO poisoning patients.Comparedwithpatientstreated withNBO, a lower percentage of patientstreated withHBO reported headache (16.2% vs 16.5%, relative risk [RR]=0.83, 95%CI=0.38–1.80), memory impairment (18.2% vs 23.8%, RR=0.80, 95%CI=0.43–1.49), difficulty concentrating (15.0% vs 18.4%, RR=0.86, 95%CI=0.55–1.34), and disturbed sleep (14.7% vs 16.2%, RR=0.91, 95% CI=0.59–1.39). Two sessions of HBO treatment exhibited no advantage over one session.Conclusions: The meta-analysis indicated that compared with CO poisoning patients treated with NBO, HBO treated patientshave a lower incidence of neuropsychological sequelae, including headache, memory impairment, difficulty concentrating, disturbedsleep, and delayed neurological sequelae. Taking into consideration the cost-effectiveness of one session of HBO, one session ofHBO treatment could be an economical option for patients with CO poisoning with high severity.Abbreviations: ATA = atmospheres absolute, CI = confidence intervals, CO = carbon monoxide, DNS = delayed neurologicalsymptoms, HBO = hyperbaric oxygen, HBOT = hyperbaric oxygen therapy, ITT = intention-to-treat, NBO = normobaric oxygen,RCT = randomized controlled trials, RR = relative risk.