Abstract: Objective To evaluate the efficacy of two doses of hyperbaric oxygen therapy (HBOT) on delayed encephalopathy after carbonmonoxide poisoning (DEACMP). Methods 68 patients with DEACMP were divided into two groups, the 30 sessions of HBOT group(30-HBOT group) and the 60 sessions of HBOT group (60-HBOT group), who were given HBOT 30 and 60 times respectively. All patientswere assessed with Mini-Mental State Examination (MMSE) and fluid attenuated inversion recovery (Flair) magnetic resonance imaging ofbrain immediately before, 35 d and 70 d after HBOT. Results The MMSE score was significantly higher in 60-HBOT group than in30-HBOT group 70 d after HBOT (P<0.01). All of patients showed diffuse and confluent hyper-intensity over the bilateral periventricularwhite matter and centrum semiovale on conventional T2WI and Flair, which improved. Conclusion HBOT is effective on DEACMP, especiallywith 60 times.

Key words: hyperbaric oxygen therapy, delayed encephalopathy after carbon monoxide poisoning, Mini-Mental State Examination, magnetic resonance imaging