Preventing hypoxemia during colonoscopy. A randomized controlled trial of supplemental oxygen.

Hypoxia as measured by pulse oximetry is well recognized in patients undergoing colonoscopy. A single trial of supplemental oxygen therapy has been shown to diminish the observed desaturation during colonoscopy. We further defined the role of supplemental oxygen during colonoscopy in a randomized controlled trial. Ninety-four patients undergoing routine colonoscopy were randomized to oxygen (2 L by nasal prongs) or placebo (nasal prongs only) arms. The physician and patients were blinded to which arm they were in. Sixty-four percent of patients in the placebo arm desaturated (less than 90% saturation) versus 29% in the treatment arm (p less than 0.001). There were no complications observed in either arm. We conclude that supplemental oxygen will decrease but not prevent the incidence of arterial desaturation observed during colonoscopy.