Systematic Review Of The Comparison Between Adrenaline ( Epinephrine) And Selective Beta 2-Agonist In The Setting Of Adults Or Children With Acute Asthma

Background: International guidelines do not recommend the use of adrenaline in acute asthma unless associated with anaphylaxis and angioedema. We conducted a systematic review to determine the efficacy of adrenaline in comparison to selective β2-agonist in acute asthma. Methods: We included peer-reviewed publications of randomised controlled trials (RCTs) that enrolled children or adults in any healthcare setting and compared adrenaline by any route to selective β2-agonists by any route for an acute asthma exacerbation. The primary outcome was treatment failure as indicated by hospitalisation, need for additional treatment, intubation, or death. Results: Thirty-eight of 1,140 studies were included. Overall quality of evidence was low. The pooled odds ratio for treatment failure with adrenaline versus selective β2-agonist was 0.99 (95% CI 0.74 to 1.34), p=0.96. There was significant statistical and clinical heterogeneity, I2=56%, which precluded combining secondary outcome data for meta-analysis. It was not possible to determine whether adrenaline in addition to selective β2-agonist improved outcomes. Conclusion: The limited evidence available does not support the use of adrenaline in addition to selective β2-agonists in acute asthma. There is a need for high-quality double-blind RCTs to address this issue. PROSPERO registration CRD42017079472