Clinical Research Directory

Voluntary Isocapnic Hyperpnea in Hypoxia to Mitigate Acute Mountain Sickness

Sponsor: Institute of Sport - National Research Institute, Poland

Summary

This study investigates the effects of a brief Voluntary Isocapnic Hyperpnoea (VIH) on Acute Mountain Sickness (AMS) symptoms, SpO₂, blood pressure, and blood gas homeostasis in normobaric hypoxia, to evaluate whether such respiratory modulation may serve as a viable strategy to alleviate AMS symptoms. The investigation seeks to explore the physiological mechanisms underlying VIH in severe hypoxia (4200m asl) and furnish insight regarding practical means of providing immediate relief from AMS symptoms. Furthermore, given the scarcity of relevant literature, this investigation may serve as a pilot study and lay the foundation for future research. The present investigation employed a randomized crossover design. The study was conducted in the Institute of Sport - National Research Institute in Warsaw, Poland, in July and August 2025. Across 2 consecutive days, the participants underwent two 2-hour sessions under hypoxia of 4200m asl (FiO2 = 12.8%) in a normobaric chamber (Air Sport, Międzyzdroje, Poland). The sessions were held at the same time of day, between 17:00 and 19:00. Temperature (approximately 21 °C), humidity (45-50%), and gas concentration were centrally controlled and maintained at stable levels throughout the exposure period. During the control session, the participants remained seated without any activity. During the experimental session, they additionally performed a 5-minute VIH session (20 breaths/minute) after 1 hour of hypoxic exposure. Isocapnic BreathWayBetter devices (Isocapnic Technologies Inc., Kelowna, British Columbia, Canada) equipped with 6-liter breathing bags were employed to perform VIH. The accompanying Isocapnic mobile app was used to guide breathing rhythm and monitor session duration. The order of sessions was determined using block randomization within subgroups of 4-6 individuals to ensure balanced exposure to each condition. Multiple measurements were taken, including blood pressure, heart rate, SpO2, blood gasometry, and the 2018 Lake Louise AMS Score.

Official title: Could a Breathing Protocol Serve as a Non-Pharmacological Strategy to Mitigate Acute Mountain Sickness? A Randomized Crossover Trial.

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