Effect of hyperbaric oxygen on symptoms of dementia in patients with delayed encephalopathy after acute carbon monoxide poisoning.

Objectives: Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is the most severe complication of carbon monoxide poisoning, which seriously endangers patients' quality of life. This study aims to investigate the efficacy of hyperbaric oxygen (HBO) on improving dementia symptoms in patients with DEACMP.

Methods: A retrospective analysis was performed on DEACMP patients, who visited Xiangya Hospital, Central South University from June 2014 to June 2020. Among them, patients who received conventional drug treatment combined with HBO treatment were included in an HBO group, while those who only received conventional drug treatment were included in a control group. HBO was administered once daily. Patients in the HBO group received 6 courses of treatment, with each course consisting of 10 sessions. The Hasegawa Dementia Scale (HDS) was used to diagnose dementia, and the Clinical Dementia Rating (CDR) was used to grade the severity of dementia for DEACMP. The Alzheimer's Disease Assessment Scale-Cognitive Section (ADAS-Cog), the Functional Activities Questionnaire (FAQ), the Neuropsychiatric Inventory (NPI), and the Clinician's Interview-Based Impression of Change-Plus Caregiver Input (CIBIC-Plus) were performed to assess cognitive function, ability to perform activities of daily living (ADL), behavioral and psychological symptoms, and overall function. The study further analyzed the results of objective examinations related to patients' dementia symptoms, including magnetic resonance imaging detection of white matter lesions and abnormal electroencephalogram (EEG). The changes of the above indicators before and after treatment, as well as the differences between the 2 groups after treatment were compared.

Results: There was no significant difference in the HDS score and CDR grading between the 2 groups before treatment (both >0.05). After treatment, the score of ADAS-Cog, FAQ, NPI, and CIBIC Plus grading of the 2 groups were significantly improved, and the improvement of the above indicators in the HBO group was greater than that in the control group (all <0.05). The effective rate of the HBO group in treating DEACMP was significantly higher than that of the control group (89.47% vs 65.87%, <0.05). The objective examination results (white matter lesions and abnormal EEG) showed that the recovery of patients in the HBO group was better than that in the control group.

Conclusions: Hyperbaric oxygen can significantly relieve the symptoms of dementia in patients with DEACMP.