Acute carbon monoxide poisoning is a common and frequently occurring disease in winter and spring in China, with high disability and mortality. Delayed encephalopathy is a serious sequela after the pseudo-convalescence. Its mechanism is complex, including environmental and genetic factors, hypoxia and energy metabolism disorder, cytotoxicity and oxygen free radical damage, immune disorder and inflammatory activation, neurotransmitter disorder, brain parenchymal changes, vascular and hemorheological abnormalities, calcium overload, and cell apoptosis. At present, methods for predicting delayed encephalopathy in acute carbon monoxide poisoning include detailed inquiry of medical history, laboratory examination of relevant indicators, electrophysiological examination, brain imaging examination, and evaluation scale prediction. This review summarizes the research status of the pathogenesis and early prediction methods of delayed encephalopathy in acute carbon monoxide poisoning, with a view to providing reference for future research directions.
ObjectiveTo systematically evaluate the effect of hyperbaric oxygen therapy on delayed encephalopathy caused by carbon monoxide poisoning.MethodsChina National Knowledge Infrastructure, Wanfang Data, CQVIP data, China Biology Medicine Database, PubMed, Embase, and Cochrance Library were searched by computer for randomized controlled trials on hyperbaric oxygenation for delayed encephalopathy caused by carbon monoxide poisoning which were published in English or Chinese from the dates of establishment of the databases to March 31st, 2019. After literature including, excluding, and screening, RevMan 5.2 software was used to conduct a meta-analysis.ResultsA total of 25 studies were included, including 1 797 patients, 924 in the hyperbaric oxygen therapy group (the trial group) and 873 in the control group. The clinical effective rate [relative risk (RR)=1.24, 95% confidence interval (CI) (1.19, 1.30), P<0.000 01], the normal rate of electroencephalogram [RR=2.10, 95%CI (1.18, 3.75), P=0.01], the Mini-Mental State Examination score [standard mean difference (SMD)= 3.19, 95%CI (2.06, 4.32), P<0.000 01], and the Activities of Daily Living score [SMD=1.46, 95%CI (1.02, 1.90), P<0.000 01] were all higher in the trial group than those in the control group.ConclusionHyperbaric oxygen therapy for delayed encephalopathy caused by carbon monoxide poisoning can improve symptoms.