Article type
Year
Abstract
Objectives: to compare the efficacy of different medicines in the prevention of acute mountain sickness (AMS).
Methods: we searched PubMed, Embase, Clinicalkey, and the Cochrane Library for randomized controlled trials ((RCT) Figure 1). According to 2014 Wilderness Medical Society Practice Guidelines, inclusion criteria about the ascent profile in moderate-to-high risk for AMS were:
1) ascending from less than 1200 m to more than 2800 m in one day;
2) ascending more than 500 m per day at altitudes above 3000 m.
Study subjects were healthy adults aged 18 to 65 and had no history of AMS. We applied a Microsoft Excel-based tool called NetMetaXL, which provided an interface for conducting a Bayesian network meta-analysis with WinBUGS.
The main outcome measure was the incidence of AMS based on 2018 Lake Louise AMS score (Table 1). A total score of 3 or higher, in the presence of a headache, was considered diagnostic for AMS.
Results: we included five RCTs and 838 participants (Tables 2 to 3). In pairwise comparisons between eight arms (Figure 2), there was a trend of lower AMS incidence compared with placebo for: oral 125 mg acetazolamide twice daily (odds ratio (OR) 0.12, 95% credible interval (CRI) 0.02 to 0.51), inhaled 200 μg budesonide twice daily (OR 0.18, 95% CRI 0.06 to 0.43), oral 4 mg dexamethasone twice daily (OR 0.27, 95% CRI 0.08 to 0.86), oral 250 mg acetazolamide twice daily (OR 0.43, 95% CRI 0.21 to 0.89), oral 25 μg procaterol twice daily (OR 0.47, 95% CRI 0.14 to 1.63), inhaled 160 μg budesonide/4.5 μg formoterol twice daily (OR 0.49, 95% CRI 0.14 to 1.73). However, the study showed that oral 50 mg spironolactone twice daily does not prevent AMS (Table 4). There were no significant differences in AMS incidence between oral 125 mg acetazolamide twice daily and 250 mg acetazolamide twice daily (OR 0.27, 95% CRI 0.05 to 1.35). The surface under the cumulative ranking curve area (SUCRA, Figure 3) of eight arms showed that the best choice is oral 125 mg acetazolamide twice daily (0.8956), and the worst choice is oral 50 mg spironolactone twice daily (0.04243).
Conclusion: the standard medicines used to prevent AMS are acetazolamide and dexamethasone, however, other options such as ginkgo or ibuprofen can not be included in the study because of the criteria setting. Further studies and more people are required to decide which medicine, dose, and when to start is appropriate.
Methods: we searched PubMed, Embase, Clinicalkey, and the Cochrane Library for randomized controlled trials ((RCT) Figure 1). According to 2014 Wilderness Medical Society Practice Guidelines, inclusion criteria about the ascent profile in moderate-to-high risk for AMS were:
1) ascending from less than 1200 m to more than 2800 m in one day;
2) ascending more than 500 m per day at altitudes above 3000 m.
Study subjects were healthy adults aged 18 to 65 and had no history of AMS. We applied a Microsoft Excel-based tool called NetMetaXL, which provided an interface for conducting a Bayesian network meta-analysis with WinBUGS.
The main outcome measure was the incidence of AMS based on 2018 Lake Louise AMS score (Table 1). A total score of 3 or higher, in the presence of a headache, was considered diagnostic for AMS.
Results: we included five RCTs and 838 participants (Tables 2 to 3). In pairwise comparisons between eight arms (Figure 2), there was a trend of lower AMS incidence compared with placebo for: oral 125 mg acetazolamide twice daily (odds ratio (OR) 0.12, 95% credible interval (CRI) 0.02 to 0.51), inhaled 200 μg budesonide twice daily (OR 0.18, 95% CRI 0.06 to 0.43), oral 4 mg dexamethasone twice daily (OR 0.27, 95% CRI 0.08 to 0.86), oral 250 mg acetazolamide twice daily (OR 0.43, 95% CRI 0.21 to 0.89), oral 25 μg procaterol twice daily (OR 0.47, 95% CRI 0.14 to 1.63), inhaled 160 μg budesonide/4.5 μg formoterol twice daily (OR 0.49, 95% CRI 0.14 to 1.73). However, the study showed that oral 50 mg spironolactone twice daily does not prevent AMS (Table 4). There were no significant differences in AMS incidence between oral 125 mg acetazolamide twice daily and 250 mg acetazolamide twice daily (OR 0.27, 95% CRI 0.05 to 1.35). The surface under the cumulative ranking curve area (SUCRA, Figure 3) of eight arms showed that the best choice is oral 125 mg acetazolamide twice daily (0.8956), and the worst choice is oral 50 mg spironolactone twice daily (0.04243).
Conclusion: the standard medicines used to prevent AMS are acetazolamide and dexamethasone, however, other options such as ginkgo or ibuprofen can not be included in the study because of the criteria setting. Further studies and more people are required to decide which medicine, dose, and when to start is appropriate.
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