Resting arterial oxygen saturation and breathing frequency as predictors for acute mountain sickness development: a prospective cohort study.

Abstract

INTRODUCTION:

The study evaluated the predictive value of arterial oxygen saturation (SaO2) after 30-min hypoxic exposure on subsequent development of acute mountain sickness (AMS) and tested if additional resting cardio-respiratory measurements improve AMS prognosis.

METHODS:

Fifty-five persons were exposed to a simulated altitude of 4,500 m (normobaric hypoxia, FiO2 = 12.5%). Cardio-respiratory parameters, SaO2, blood lactate, and blood pressure were measured after 30 min of exposure. AMS symptoms were recorded after 3, 6, 9, and 12 h (Lake-Louise Score). Three models, based on previously published regression equations for altitude-dependent SaO2 values of AMS-susceptible (SaO2-suscept = 98.34 - 2.72 ∗ alt - 0.35 ∗ alt(2)) and AMS-resistant (SaO2-resist = 96.51 + 0.68 ∗ alt - 0.80 ∗ alt(2)) persons, were applied to predict AMS. Additionally, multivariate logistic regression analyses were conducted to test if additional resting measurements improve AMS prediction.

RESULTS:

The three models correctly predicted AMS development in 62%, 67%, and 69% of the cases. No model showed combined sensitivity and specificity >80%. Sequential logistic regression revealed that the inclusion of tidal volume or breathing frequency in addition to SaO2 improved overall AMS prediction, resulting in 78% and 80% correct AMS prediction, respectively.

CONCLUSION:

Non-invasive measurements of SaO2 after 30-min hypoxic exposure are easy to perform and have the potential to detect AMS-susceptible individuals with a sufficient sensitivity. The additional determination of breathing frequency can improve success in AMS prediction.

• Authors: Martin Faulhaber, Maria Wille, Hannes Gatterer, Dieter Heinrich, Martin Burtscher
• Journal: Sleep & breathing = Schlaf & Atmung (Sleep Breath) Vol. 18 Issue 3 Pg. 669-74 (Sep 2014) ISSN: 1522-1709 [Electronic] Germany
• PMID: 24436093 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Lactic Acid
• Oxygen

Topics

• Acute Disease
• Adult
• Altitude Sickness (diagnosis, physiopathology)
• Atmosphere Exposure Chambers
• Cohort Studies
• Disease Susceptibility
• Female
• Humans
• Hypoxia (diagnosis, physiopathology)
• Lactic Acid (blood)
• Male
• Oxygen (blood)
• Predictive Value of Tests
• Prospective Studies
• Respiratory Rate (physiology)