Related Experiment Video
Updated: Aug 22, 2026

A Model to Simulate Clinically Relevant Hypoxia in Humans
Published on: December 22, 2016
Acute mountain sickness is related to nocturnal hypoxemia but not to hypoventilation
1Pulmonary Division and Intensive Care Unit, Dept of Internal Medicine, University Hospital Zurich, Switzerland.
Abstract:
The purpose of the study was to investigate determinants of acute mountain sickness after rapid ascent to high altitude. A total of 21 climbers were studied ascending from <1,200 m to Capanna Regina Margherita, a hut in the Alps at 4,559 m, within <24 h. During their overnight stay at 4,559 m, breathing patterns and ventilation were recorded by calibrated respiratory inductive plethysmography along with pulse oximetry. In the following morning, acute mountain sickness was assessed. Altogether, 11 mountaineers developed pronounced symptoms of acute mountain sickness (Lake Louise score > or =5) and 10 did not (controls). Compared to controls, subjects with acute mountain sickness had lower nocturnal oxygen saturation (mean+/-SD 59+/-13% versus 73+/-6%), higher minute ventilation (7.94+/-2.35 versus 6.06+/-1.34 L x min(-1)), and greater mean inspiratory flow, a measure of respiratory centre drive (0.29+/-0.09 versus 0.22+/-0.05 L x s(-1)). Periodic respiration was prevalent but not significantly different among the two groups (apnoea/hypopnea index 60.1+/-34.6 versus 47.1+/-42.6 events per h). The data suggest that pronounced nocturnal hypoxemia, which was not related to hypoventilation, may have promoted acute mountain sickness. Periodic breathing seems not to play a predominant role in the pathogenesis of acute mountain sickness.
Related Concept Videos
Hyperpnea and Hyperventilation
Acute Respiratory Failure-II
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
Alterations in Respiration II
In Biot's breathing, the respiratory rate and depth are irregular, alternating between periods of deep gasping and apnea. Common causes include...
Acute Respiratory Failure-III
Hypoxia
Types of Hypoxia
There are four primary types of hypoxia, each resulting from a different cause:
1. Anemic hypoxia: This type occurs due to insufficient oxygen delivery caused by a lack of red blood cells (RBCs) or RBCs with abnormal or...
Atelectasis II: Pathophysiology