Efficacy and safety of glucocorticoids combined with hyperbaric oxygen therapy in the treatment of delayed encephalopathy after acute carbon monoxide poisoning: study protocol for a randomized controlled trial

Background: About half of patients with acute carbon monoxide (CO) poisoning suffer from delayed post-anoxic encephalopathy. Days or weeks after apparent recovery from acute CO poisoning, patients present with sudden onset neurophysiological symptoms, mainly symptoms of dementia, with a high risk of permanent disability or death. Glucocorticoids not only regulate the biosynthesis and metabolism of blood glucose, fat, and protein, but also inhibit the immune response and exhibit anti-inflammatory, anti-toxic, and anti-shock effects. Glucocorticoids can improve the clinical symptoms of delayed encephalopathy; however, the therapeutic effects of glucocorticoids combined with hyperbaric oxygen therapy (HBOT) on delayed encephalopathy after acute CO poisoning are poorly understood. Methods/Design: This is a single-center, prospective, single-blind, randomized controlled trial, which will be performed at Baotou Center Hospital, China. A total of 120 eligible patients with delayed encephalopathy after acute CO poisoning will be randomly assigned to receive either basic treatment + HBOT + intravenous dexamethasone (trial group, n = 60) or basic treatment + HBOT (control group, n = 60). Intravenous injection of dexamethasone (10 mg, once a day, for 14 successive days) will be performed. HBOT (once a day, for 14 successive days) will be administered through a multi-place hyperbaric chamber that will be pressurized with 100% O 2 to 2-2.2 atmospheres absolute within 25 minutes, followed by 60 minutes of pressure stabilization, 10 minutes of resting, and 25 minutes of depressurization. The primary and secondary outcome measures of this study will be evaluated at baseline, 7, 14, 30, 60 and 90 days after treatment. The primary outcome measure is the Barthel Index of Activities of Daily Living change. The secondary outcome measures are Mini-Mental State Examination score, modified Ashworth Scale score and European Quality of Life-5 Dimensions questionnaire score, as well as adverse reactions and death rate. Discussion: This study will be conducted to analyze the clinical therapeutic efficacy and safety of glucocorticoids combined with hyperbaric oxygen therapy in the treatment of delayed encephalopathy after acute CO poisoning. Trial registration: This study protocol was registered with Chinese Clinical Trial Registry (registration number: ChiCTR-IPR-16009743) on 5 November 2016. Ethics: This study protocol has been approved by the Ethics Committee, Baotou Central Hospital, China and will be performed in accordance with Declaration of Helsinki formulated by the World Medical Association. Informed consent: Written informed consent will be obtained from patients′ relatives prior to involvement in the clinical trial