Inhaled budesonide for the prevention of acute mountain sickness: A meta-analysis of randomized controlled trials

Background: Altitude induces acute mountain sickness (AMS), which can affect the health or limit the activities of 15-80% of climbers and workers. Budesonide has been applied to prevent AMS. However, its prophylactic efficacy is controversial. Our purpose was to conduct a meta-analysis to assess whether budesonide qualifies as a prophylaxis for AMS. Methods: A literature search was performed in PubMed, EMBASE, Web of Science, and the Cochrane Library in February 2019. Only randomized controlled trials (RCTs) were selected. The main outcome, AMS, was estimated with the relative risk (RR), weighted mean difference (WMD), and 95% confidence intervals (95% CI). The statistical analysis was performed using Rev. Man 5.3. Results: Five groups in six articles met the eligibility criteria with 304 participants, including two articles with the sameparticipants but different measurements. Inhaled budesonide showed a potential trend towards preventing AMS, but it was not statistically significant (RR=0.68, 95% CI: 0.41-1.13, p=0.14). The subgroup analysis based on dosage (200 mu g) did not have significant results. A similar trend was observed for severe AMS and in subgroups stratified by the Lake Louise Score (LLC). However, there was a significant improvement in heart rate (HR) (WMD=-5.41, 95% CI:-8.26 to-2.55, p=0.0002) and pulse oxygen saturation (SPO2) (WMD =2.36, 95% CI: 1.62-3.1, p < 0.00001) in the group with inhaled budesonide. Additionally, no side effects were reported in any included study. Conclusion: The current meta-analysis indicates that inhaled budesonide does not protect against AMS or severe AMS. However, it is successful at reducing HR and increasing SPO2 without any side effects. (c) 2019 Elsevier Inc. All rights reserved.