Risk of hypoxia during flexible upper GI endoscopy in unsedated patients of a tertiary care public sector hospital in Karachi, Pakistan

ABSTRACT

To measure the changes in oxygen saturation using pulse oximetry during flexible upper gastrointestinal endoscopy in unsedated patients. This is an observational study conducted on 356 patients undergoing unsedated upper gastrointestinal Endoscopy, during April 2009 to January 2010. Complete demographic data, systemic history, smoking history, laboratory evaluation and American Society of Anesthesiologists Physical Status [ASA-PS] were recorded in all patients. Patients with severe systemic disease [ASA-PS III-VI], those who needed emergency endoscopy and with anemia of hemoglobin <8gm/dl were excluded from the study. Out of 356 patients 186 [52.2%] were male and 170 [47%.8] were female. All the patients tolerated the procedure well at the start and at the end and had no oxygen desaturation. At mid of the procedure 21 [5.9%] patients showed mild oxygen desaturation and 4 [1.1%] showed moderate oxygen desaturation while 331 [93%] showed no oxygen desaturation. No patient at any stage showed severe oxygen desaturation. Relationship of smoking, co-morbidity and clinical signs with mid procedure oxygen saturation is insignificant in both genders. It is concluded that mild to moderate hypoxia is some what common during therapeutic endoscopic procedure and of no serious consequence. However, severe hypoxia is not recorded in our study. The unsedated gastrointestinal endoscopy is a safe procedure for the diagnostic purpose, as it does not produce hypoxia during this; therefore pulse oximetry is not a precondition in patients undergoing unsedated diagnostic endoscopy without severe systemic disease. We recommend monitoring through pulse oximetry in patients with age greater than 45 years and procedure longer than 8 minutes