Objective: This study aimed to compare 3 treatment modalities during sleep at an altitude of 5300 m to identify strategies for reducing the incidence of periodic breathing at high altitude. Methods: Fifteen trekkers, with identical ascent profiles and no signs or symptoms of altitude illness, served as subjects. All study participants arrived at 5300 m after a gradual ascent from 1300 m. On their second night at 5300 m, subjects were randomly assigned (with a computer-based random assignment procedure) to 1 of 4 different treatment groups: control (n = 4); 1 L/min O2 via a demand system during sleep (n = 3); 1 L/min O2/CO2 mix (1.5% CO2) via a demand system during sleep (n = 4); or 125 mg acetazolamide 30 minutes before bedtime (n = 4). Heart rate, respiration rate, blood oxygen saturation, tidal volume, minute volume, and apnea hypopnea index were measured. Results: Upon comparing the 4 groups, there were no statistically significant differences between the variables. One-way analysis of variance indicated a trend toward statistical significance for SaO2 between groups (F = 2.9, P =.08), and Tukey Honestly Significant Difference (HSD) post hoc tests indicated a trend in the SaO2 difference between the 1 L/min oxygen and control groups (P =.07). While 1-way analysis of variance suggested no difference for respiratory rate between groups (F = 2.5, P =.1), Tukey HSD indicated a trend in statistical difference of the respiratory rate between 1 L/min O2 and 1 L/min O2/CO2 mixture (P =.08). Conclusions: These statistical trends found between control and treatment groups indicate that further study is warranted.
- high altitude
- nocturnal periodic breathing
ASJC Scopus subject areas
- Emergency Medicine
- Public Health, Environmental and Occupational Health