Oxygen supplementation for work in hypoxic environments — a pilot study

Health Promotion & Physical Activity, vol. 32, pp. 35–43

Abstract

Objective: To investigate at what level of isobaric hypoxia a clinically significant decrease of PO₂ (in the blood, noted as SpO₂) occurs when non-acclimatized humans enter a hypoxic environment, and what amount of supplemental oxygen, if any, is necessary to keep SpO₂ within an acceptable range when operating in a low-oxygen environment. Material and methods: 6 volunteers were exposed to 20.9% (sea level), 19.0% (800 m / 2,620 ft), 15.5% (2,400m / 7,870 ft), 13.5% (3,400 m / 11,150 ft), and 11% (5,200 m / 17,060 ft) atmospheric oxygen saturation at rest and with 80W workload, without and with supplemental oxygen via nasal cannula and a demand system. Pulse rate and SpO₂ were measured. Results: At 15.5% oxygen or higher, participants stabilized SpO₂ above 90%. At 13.5% oxygen, participants had oxygen saturation values between 80 and 89% at rest without supplemental oxygen. At 11.0% oxygen, many participants had SpO₂ values ≤80%, but 3 of 6 showed SpO₂ values between 80 and 89%. An additional workload of 80W caused only small changes in SpO₂. An immediate and significant increase in SpO₂ was observed after supplemental oxygen administration, both at rest and during exercise. Data from isobaric hypoxia correlate well with those in hypobaric conditions. Conclusion: Working in a reduced-oxygen environment at 15% oxygen is well tolerated, with no adverse physiological or clinical effects. At ambient oxygen levels of 13.5% or lower, supplemental oxygen may be required in some individuals to maintain an acceptable blood oxygen saturation.gen saturation.

Authors 5

1. Thomas Küpper Aachen Institute of Occupational, Social and Environmental Medicine

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen Technical University, Institute of Occupational Social and Environmental Medicine, Aachen, Germany; Royal College of Physicians and Surgeons, Faculty of Travel Medicine, Glasgow, U.K

2. Peter H. Hackett

   University of Colorado Anschutz

   Affiliation as printed

   University of Colorado Anschutz, School of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Aurora, Colorado, USA

3. Frank Siedler

   Repha (Germany)

   Affiliation as printed

   WAGNER Fire Safety Consulting GmbH, Langenhagen, Germany

4. Clara Wehle Aachen Institute of Occupational, Social and Environmental Medicine

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen Technical University, Institute of Occupational Social and Environmental Medicine, Aachen, Germany

5. Andreas Werner
   Affiliation as printed

   RWTH Aachen Technical University, Institute of Occupational Social and Environmental Medicine, Aachen, Germany; Charité University Hospital, Center of Space Medicine and Extreme Environments, Institute of Occupational, Social and Environmental Medicine, Department of Physiology, Berlin, Germany; German Armed Forces Medical Care Centre Munster, Occupational Health Service, Munster, Germany