Effects of sedation and supplemental oxygen during upper alimentary tract endoscopy.

The effects of supplemental oxygen therapy on arterial oxygen saturation (SaO2) in unsedated and sedated patients have been studied using pulse oximetry. Hypoxia (minimum SaO2 92% or less) occurred in 41% of unsedated patients breathing room air but in only 11% (p < 0.01) of those receiving supplemental oxygen (41/min) by nasal cannulae. Comparable effects were seen in sedated patients (60% versus 16%, respectively, p < 0.01). Hypoxia during upper alimentary tract endoscopy is common with or without sedation and can be reduced by supplemental oxygen.