A novel monitoring in endoscopic sedation: Oxygen Reserve Index

Abstract

Abstract Purpose: To assess whether ORi guided pre-oxygenation and ORi monitoring in addition to capnography and pulse oximetry is more effective than standard monitoring alone to prevent cardio-respiratory events in endoscopic sedation. Methods: This prospective, randomized, single blinded study included 200 endoscopy patients which randomized to two groups. All the participants had ORi, SpO2, ETCO2, non-invasive blood pressure and heart rhythm monitoring. In Group I anesthesiologist was blinded to ORi. Five min pre-oxygenation (5 L/min via nasal cannula) applied to all participant in sitting position, with ORi guidance to reach steady state in ORi. Propofol boluses were applied for sedation. Mild and moderate desaturation, and hypoventilation were recorded. Results: Seventeen per cent moderate desaturation (SpO2<90%) observed in Group I whereas rate was 7.6% in Group II (p:0.06). Hypoventilation rate was 23% and 12% in Group I and II respectively (p:0.057). Low ORI rate was statistically significantly higher in Group I (19%) compared to Group II (4.3%)(p:0.002). Conclusions: Our results showed that ORi has ability to diminish hypoxemic events and putting patients in a mild hyperoxemic state and endeavor to keep this state can be alternative and reliable method for endoscopic sedation.