Comparison of oxygen delivery methods during monitored anaesthesia care for flexible endoscopy procedures

Abstract

Introduction: Endoscopic procedures are usually performed under monitored anaesthesia care. Hypoxia could occur due to the sedative effects of drugs used during flexible endoscopic procedures and sharing of airway between endoscopist and anaesthesiologist. Administration of oxygen could reduce the incidence of hypoxia. Aims and Objectives: We aimed to study whether delivery of oxygen through nasal prongs or through a T-piece without an after-burner connected to a nasopharyngeal airway could reduce the incidence of hypoxia during monitored anaesthesia care for flexible endoscopic procedures. While our primary objective was to compare the incidence of hypoxia (oxygen saturation [SpO2] < 90% lasting for at least 15 s), our secondary objectives were to compare the level of sedation and incidence of adverse events. Patients and Methods: Sixty six patients (33 in each group) aged between 18 and 80 years were randomly allocated to one of two groups to receive oxygen through nasal prongs or through a T-piece without an after-burner connected to a nasopharyngeal airway. Drug requirement, SpO2 and adverse events were monitored pre-procedure and every 5 min thereafter till the end of the procedure. Results: There was no statistically significant difference in the mean SpO2 (P > 0.05), but the incidence of hypoxia was less in patients receiving oxygen through nasal prongs as compared to patients receiving oxygen through a T-piece without an after-burner connected to a nasopharyngeal airway (P < 0.05). Adverse events were found to be comparable between two groups. Conclusion: During flexible endoscopy under monitored anaesthesia care, oxygen delivery through nasal prongs results in a lower incidence of hypoxia as compared to oxygen delivery through a T-piece without an after-burner connected to a nasopharyngeal airway.