Objectives Oral Glucocorticoid can prevent Acute Mountain Sickness (AMS), but has much systemic side-effect. We sought to evaluate whether the inhaling of Budesonide can prevent AMS.
Methods A method of randomised double-blinded, controlled, prospective was taken. 80 subjects were randomly divided into four groups, who inhale Budesonide twice a day, 200ug each time; Procaterol tablet twice a day, 25ug each time; Inhaled Budesonide/Fomoterol, twice a day, 160ug/4.5ug each time; Placebo control group (twice a day, one tablet per time). The first three day before acute exposed to high altitude to the morning of setting off day, subjects took these drugs. The subjects acute exposure to Lhasa (3700m) from 500m altitude plain by plane within 2.5h. Scored the Lake Louis AMS at 20h, 72h, and 120h after exposure to high altitude respectively, took examination of blood pressure (BP), heart rate (HR), oxygen saturation (SpO2), ECG, echocardiogram, and pulmonary function at same time.
Results Compared with placebo, after the exposure to high altitude respectively for 20h, 72h, 120h, inhaled Budesonide could reduce the incidence of AMS without any side effects (70% to 25%, P < 0.05; 10% to 5%, P > 0.05; 10% to 5%, P > 0.05); Other two kinds of drugs had a mild effect on reducing AMS in early period (70% to 50%, P > 0.05), but still higher than placebo group at 72h and 120h (30% VS. 10%, P > 0.05; 20% VS. 10% P > 0.05). The SpO2 were higher in all drug groups than Placebo after 20h exposure (P = 0.0001), and this continued to be so after 120h (P = 0.334). There was no difference of pulmonary function data among four groups (P > 0.05). In the early period of exposure, there was an obvious decline for SpO2 of all the subjects (98.1% to 88.12% P < 0.01), and the SpO2 increased with the time extension of exposure to high altitude, but was still lower than that was in plain at 120h (98.1% VS. 92.04%, P < 0.01). Resting HR had an obvious increase early at high altitude and later it was in a steady-state level.
Conclusions Inhaling of Budesonide 400ug/day can prevent AMS at the early period of acute exposure to high altitude, and also can prevent the decline of SpO2 caused by acute exposure to high altitude. Such effect can last 72h to 120h at most, and will not adverse affect the high altitude acclimatization of individual. The reduction of the incidence of AMS may be related to the increase of SpO2 partially, but may have no relation to pulmonary function. The prevention effect of β2 receptor agonist on AMS is not obvious, and inhaling it may have unfavourable influence on high altitude acclimatisation after the application.