A quantitative systematic review of hyperbaric oxygen therapy for acute ischaemic stroke

Aims: It has been postulated that hyperbaric oxygen therapy (HBOT) may improve outcome in patients following acute ischaemic stroke. The aim of this review was to assess the effectiveness and safety of adjunctive HBOT in the treatment of acute ischaemic stroke. Methods: A systematic search for all randomized controlled trials that compared HBOT in the treatment for acute ischaemic stroke in comparison to a controll group (sham or placebo treatment) was performed (Cochrane Stroke Group Trials Register, Cochrane Central Register of controlled Trials, Medline, Embase, CINAHL, DORCTIHM, hand-search of journals and conference proceedings). Three authors extracted the data independently. Each trial was assessed for validity. Data were analysed with RevMan 4.2. For proportions (dichotomous outcomes) relative risk (RR) was used. Continuous data were converted to the mean difference (MD) using the inverse variance method and an overall MD was calculated. Results: Three randomised controlled trials (106 participants) matched the inclusion criteria. Analysis of the pooled data revealed no significant differences in the mortality after 6 months in the HBOT group compared to the control group (relative risk 0.61, 95% confidence interval (CI): 0.17–2.2, P value: 0.45). An improvement in 2 out of 15 functional scales was noted in the group receiving HBOT in comparison to the controll group after 1 year follow-up either: the mean Trouillas Disability Scale was lower after HBOT (MD: 2.2 points reduction with HBOT, 95% CI: 0.15–4.3, P value: 0.04) and the mean Orgogozo Scale was higher (MD: 27.9 points, 95% CI: 4.0–51.8, P value: 0.02). Other trials or funtional scales didn't reflect these improvements. Report of adverse effects was poor and did not allow meaningful comparisons. Conclusions: No evidence of a clinical outcome improvement after an acute ischaemic stroke was found in this systematic review. Although evidence is insufficient to present clear directives, a clinical benefit doesn't seem to be likely.