Pulse Oximetry Saturation Levels during Routine Unsedated Diagnostic Upper Gastrointestinal Endoscopy

Abstract

Background: Diagnostic procedures account for over 90% of all upper gastrointestinal endoscopies. Pulse oximetry saturation (SpO₂) levels were assessed in patients attending for routine unsedated diagnostic gastroscopy to identify factors associated with oxygen desaturation. Methods: Three hundred and thirty unsedated patients were monitored with continuous pulse oximetry. A further 154 patients who requested sedation prior to endoscopy were studied as a positive control group. Results: SpO₂ levels were lower in sedated compared to unsedated patients (P < 0.0001). Six unsedated patients (2%) desaturated to 90% or less during endoscopy compared to 32 sedated patients (21%) (P < 0.0001). SpO₂ levels in unsedated patients were not related to patient sex, age, cigarette smoking, endoscope diameter, basal SpO₂ levels or duration of endoscopy. In contrast, examination of the pharyngeal area and epiglottis (P = 0.0002) and a longer intubation time (P = 0.0002) were associated with lower SpO₂ levels. The lowest SpO₂ level recorded during unsedated endoscopy was 88%. Conclusion: Pulse oximetry is not a prerequisite to performing routine unsedated diagnostic gastroscopy in patients without severe systemic disease.

• Oxygen Saturation Pulse Oximetry Sedation Unsedated Endoscopy Upper Gastrointestinal Endoscopy