Heartwire
Use of oxygen in MI patients questioned by new Cochrane review
June 15, 2010
Sue Hughes
Alicante, Spain and Guildford, UK – There is no conclusive evidence from randomized controlled trials to support the routine use of inhaled oxygen in patients with acute MI, a new analysis in the Cochrane Database of Systematic Reviews concludes [1]. In fact, the review of available clinical-trial data suggests that oxygen might actually be harmful.
“A definitive randomized controlled trial is urgently required given the mismatch between trial evidence suggestive of possible harm from routine oxygen use and recommendations for its use in clinical practice guidelines,” the authors state.
For the review, published online June 16, 2010, researchers led by Dr Juan Cabello (Hospital General Universitario de Alicante, Spain) and Prof Tom Quinn (University of Surrey, Guildford, UK) pooled the results of three randomized trials involving 387 MI patients. There were a total of only 14 deaths. Results showed that oxygen use was associated with a relative risk of death of 2.88 (95% CI 0.88-9.39) in an intention-to-treat analysis and 3.03 (95% CI 0.93-9.83) in patients with confirmed MI. While suggestive of harm, the small number of deaths recorded meant that this could be a chance occurrence, the authors stress.
Pain, measured by analgesic use, did not appear to be affected by oxygen use, with a relative risk for analgesic use of 0.97 (95% CI 0.78-1.20).
Quinn commented to heartwire: “There is no hard evidence supporting the use of oxygen in MI. It is used for pathophysiological reasons. People think that because MI is caused by a lack of oxygen to the heart, giving more oxygen must be a good thing. But it is always a problem moving from that reasoning to clinical-trial evidence.” (more)
The Use of Oxygen After a Heart Attack: Pathophysiological Reasoning?
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