Cerebral oximetry monitoring in non-intubated patients undergoing endoscopic retrograde cholangiopancreatography under propofolinduced sedation: a prospective observational study
Background Prolonged propofol-induced deep sedation increases the risk for sedationrelated complications. Cerebral oximetry enables prompt assessment of tissue oxygenation by demonstrating the regional hemoglobin oxygen saturation (rSO2) of the cerebral cortex. This study aimed to: evaluate cerebral oxygenation under deep sedation during an endoscopic retrograde cholangiopancreatography (ERCP) procedure; determine the cerebral desaturation event (CDE) rate; and assess the predictive capacity of CDEs for sedation-related complications.
Methods All consecutive patients who underwent ERCP between September and December 2019 were included prospectively. Propofol monotherapy was used and sedation level was assessed using the bispectral index (BIS). The target level of sedation was deep sedation, defined by BIS values 40-60. Participants were monitored with arterial blood gas analysis and INVOS 5100C cerebral oximeter. RSO2 values were registered prior to sedation (baseline value), every 5 min during the sedation period and at recovery of consciousness. BIS values were recorded simultaneously. CDE was defined as a drop >10% from individual baseline rSO2.
Results Sixty patients were enrolled. Mean baseline rSO2 was 65.1% and BIS values ranged from 18- 85. No significant correlation was observed between mean rSO2 measurements and mean BIS values throughout the recordings (P = 0.193). Data from patients aged ≥65 years were analyzed separately and the results were similar. The CDE rate was 2.7%, but no CDE was associated with clinical manifestations. Twelve sedation-related complications occurred without the presence of cerebral desaturation.
Conclusion Cerebral oxygenation remained independent of changes in sedation depth and cerebral oximetry monitoring did not detect complications earlier than standard monitors.
Keywords Cerebral oxygenation, deep sedation, cerebral oximetry, near infrared spectroscopy, ERCP
Ann Gastroenterol 2021; 34 (5): 736-742