Arterial oxygen saturation during upper gastrointestinal endoscopy: the effects of a midazolam/pethidine combination.

This study was performed to assess the severity and duration of hypoxia during and after prolonged upper gastrointestinal endoscopy. Twenty patients were studied using a non-invasive pulse oximeter. Significant reductions in oxygen saturation were noted during endoscopy and remained below the preexamination level during the one hour period after the examination. This study indicates that pulse oximetry is a useful monitor for detection of hypoxia during and after endoscopy.