Abstract
Objective: To evaluate the effect of supplementary oxygen on heart rate and arterial oxygen saturation during colonoscopy. Design: Controlled study. Setting: Two university hospitals, Denmark. Subjects: 40 patients having colonoscopy. Interventions: 20 patients were given supplementary oxygen through nasal prongs (2 L/min), and 20 patients breathed room air during colonoscopy. All patients were given conscious sedation and were monitored with a pulse oximeter during colonoscopy. Main outcome measures: Tachycardia (pulse rate >100 min