Related Experiment Video
Updated: Aug 11, 2026

A Model to Simulate Clinically Relevant Hypoxia in Humans
Published on: December 22, 2016
Apnea-induced hemoglobin desaturation during one-lung vs two-lung ventilation
1Department of Anesthesiology, American University of Beirut, Lebanon. abaraka@aub.edu.lb
Purpose:
To compare the rate of apnea-induced hemoglobin desaturation during one-lung ventilation (OLV) vs. two-lung ventilation (TLV) in patients undergoing thoracic surgery.
Methods:
Six patients undergoing thoracotomy or thoracoscopy were included. Each patient served as his/her own control. The lungs were ventilated with oxygen 100% using TLV, followed after 20-30 min by OLV and the resultant PaO2 was measured. Apnea was then induced following the two techniques of ventilation, and the times for every 1% decrease in hemoglobin saturation from 100% to 95%, as monitored by pulse oximetry, were recorded. The times for every 1% decrease in the saturation were compared in the two groups.
Results:
The mean PaO2 value following TLV (445+/-99 mm Hg) was higher than the mean PaO2 following OLV (156+/-18 mm Hg). Also, the mean time for subsequent apnea induced hemoglobin desaturation from SpO2 100% to 95% following TLV was twice the time of desaturation following OLV (6.3+/-1.2 min vs. 3.2+/-0.5 min, P<0.05).
Conclusion:
Hemoglobin desaturation occurs more rapidly during apnea following OLV than TLV. The rapid desaturation may be attributed to the decrease of FRC, associated with an increased transpulmonary shunting. The results suggest that two-lung ventilation with oxygen 100% provides a greater safety margin than one-lung ventilation with oxygen 100% whenever ventilation is interrupted.
More Related Videos
06:22Surfactant Depletion Combined with Injurious Ventilation Results in a Reproducible Model of the Acute Respiratory Distress Syndrome (ARDS)
Published on: April 7, 2021
08:44Dual Test Gas Pulmonary Diffusing Capacity Measurement During Exercise in Humans Using the Single-Breath Method
Published on: February 2, 2024
Related Concept Videos
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...
Hyperpnea and Hyperventilation
Acute Respiratory Failure-I
Definition: It is defined by specific criteria based on blood gas measurements. Hypoxemia happens when the partial pressure of oxygen (PaO2) falls below 60 mmHg. At the same time,...
Acute Respiratory Failure-II
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
Acute Respiratory Failure-IV
Atelectasis II: Pathophysiology