Deep Sedation in Advanced Endoscopy: Frequency and Clinical Characteristics of Patients Who Require Airway Modifications

Abstract

Background: When administered by a trained professional, the safety and efficacy of propofol in advanced endoscopy is well described. While use of propofol requires advanced airway training, it is unclear how frequently airway modifications are employed during endoscopy and which patients may be most susceptible. Objectives: Define the frequency of airway modifications (AMs) and clinical characteristics of patients who require AMs during advanced endoscopic procedures. Methods: Patients referred for advanced endoscopic procedures, including endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasound (EUS) and small bowel enteroscopy (SBE), were prospectively enrolled. Sedative dosing and patient monitoring was determined by a certified registered nurse anesthetist (CRNA). Clinical, pharmacological and endoscopic characteristics were recorded. The primary outcome variable was frequency of one or more AMs, defined as chin lift, modified mask ventilation, nasal airway, bag-mask ventilation and endotracheal intubation. Characteristics of patients who required one or more AMs (AM+) were compared to those who did not require any maneuvers (AM-). Results: 629 patients were enrolled between May, 2008 and September, 2008. 40.8% received propofol alone while 59.2% received propofol in combination with low dose opiate and/or benzodiazepine. Procedures included EUS (329), ERCP (268), and SBE or other (38). All patients met criteria for deep sedation. While only 11.5% of patients developed a pulse oximetry of <90%, one or more AMs were performed in 101 (16.1%) patients, including chin lift (86), modified mask ventilation (27), placement of a nasal airway (24), or some combination. No patients required bag-mask ventilation or endotracheal intubation. Three patients developed hypotension requiring transient use of vasopressors. There were no other significant cardiopulmonary complications. Mean body mass index (kg/m2) was significantly higher among AM+ (29.5 ± 7.4) compared to AM- (26.7 ± 6.5) patients (p=0.0001). Induction and total propofol doses (mg/kg/min), use of propofol in combination with other sedatives, procedure time, prone position, ASA class, and Malampati scores were similar across both groups. Conclusion: Despite a low rate of cardiopulmonary complications, 16.1% of patients undergoing advanced endoscopic procedures required one or more maneuvers to maintain a stable airway. Higher BMI was a predictor of requiring AMs, but dose of propofol and its use in combination with other sedatives were not. For the safe administration of propofol in advanced endoscopy, advanced airway training is warranted.