Oxygen Desaturation during Upper Gastrointestinal Endoscopy-Analysis of Predicting Factors

Continuous monitoring of oxygen saturation and heart rate with a pulse oximeter was performed in 141 consecutive patients undergoing upper gastrointestinal panendoscopy (group I, n=74), therapeutic endoscopy (group II, n=22) and endoscopic retrograde cholangiopancreatography (ERCP) (group III, n=45). A decrease in oxygen saturation ≥3% was found in 34% of patients of group I, 59% of group II, and 82% of group III, respectively. Using univariate and multivariate analysis, we found that longer duration of procedure (≥l0min), preexisting cardiopulmonary diseases and the invasiveness of the procedures were the significant factors contributing to oxygen desaturation. Tachycardia (≥l20/min) did not correlate with O2 desaturation and showed no significant change throughout the whole endoscopic procedure. In the 75 patients (53%) with oxygen desaturation, only 6 patients (8%) required O2 inhalation for maintaining normal O2 saturation to complete the endoscopic procedure. We concluded that pulse oximetry could detect hypoxia early and prevent severe cardiopulmonary complications during endoscopy.