[Pulse oximetry and thoracopulmonary surgery]

Abstract

Arterial blood gases are invasive and they provide intermittent information only. On the other hand, pulse oximetry is non invasive, providing continuous monitoring of SaO2 (SpO2). A study was therefore carried out in twelve patients undergoing lung and intrathoracic surgery to determine whether pulse oximetry was a reliable method of monitoring. The SpO2 values obtained using a Physiocontrol Oximeter (Lifestat 1600) were compared with those given by blood gas measurements (SaO2). When ventilation was switched to one-lung ventilation, PaO2 fell in all cases, whatever the method of monitoring, with PaCO2 remaining constant. 46 paired values of SaO2 were compared using linear regression analysis. Correlation between the two methods was good (r = 0.95; p less than 0.001). Pulse oximetry would therefore seem to provide a reliable method of continuous noninvasive and accurate monitoring of oxygenation during lung surgery.