Hyperbaric oxygen therapy for acute ischaemic stroke

Abstract

Background : Most cases of stroke are caused by impairment of blood flow to the brain (ischaemia) which results in a reduction in oxygen available and subsequent cell death. It has been postulated that hyperbaric oxygen therapy (HBOT) may reduce the volume of brain that will die by greatly increasing the oxygen available, and it may further improve outcome by reducing brain swelling. Some centres are using HBOT routinely to treat stroke. This is an update of a Cochrane Review first published in 2005. Objectives: To assess the effectiveness and safety of adjunctive HBOT in the treatment of acute ischaemic stroke. Search strategy: We searched the Cochrane Stroke Group Trials Register (last searched July 2008), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2008), MEDLINE (1966 to July 2008), EMBASE (1980 to July 2008), CINAHL (1982 to July 2008), the Database of Randomised Controlled Trials in Hyperbaric Medicine (DORCTIHM) (searched September 2008), and reference lists of articles. We handsearched relevant publications and contacted researchers to identify additional published and unpublished studies. Selection criteria: Randomised controlled trials (RCTs) that compared the effect of adjunctive HBOT with no HBOT (no treatment or sham). Data collection and analysis: Three review authors independently extracted data, assessed each trial for internal validity, and resolved any differences by discussion. Main results: We included six RCTs involving 283 participants. The methodological quality of the trials varied. We could only pool data for case fatalities. There were no significant differences in the case fatality rate at six months in those receiving HBOT compared with the control group (relative risk (RR) 0.61, 95% confidence interval (CI) 0.17 to 2.2, P value 0.45). Four of 14 scale measures of disability and functional performance indicated an improvement following HBOT; for example, the mean Trouillas Disability Scale was lower with HBOT (mean difference (MD) 2.2 points reduction with HBOT, 95% CI 0.15 to 4.3, P value 0.04) and the mean Orgogozo Scale was higher (MD 27.9 points, 95% CI 4.0 to 51.8, P value 0.02). Authors' conclusions: We did not find good evidence to show thatHBOT improves clinical outcomes when applied during the acute presentation of ischaemic stroke. While evidence from the six RCTs is insufficient to provide clear guidelines for practice, the possibility of clinical benefit has not been excluded. Further research is required to better define the role of HBOT in this condition. Copyright © 2009 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.