Does the ASA Physical Status Classification Predict Airway or Cardiopulmonary Complications During Routine EGD or Colonoscopy Utilizing Anesthesiologist-Directed Propofol Sedation? A Prospective Cohort Study

Abstract

Purpose: With the rise of Anesthesiologist-directed propofol sedation (ADPS) for routine EGD and colonoscopy there continues to be limited tools available to predict patients who may be at higher risk for airway (AC) and/or sedation related complications (SRC). The American Society of Anesthesiologists physical status classification system (ASAPS) has been shown to identify patients at risk for perioperative morbidity and mortality. There is no prospective data on the use of ASAPS in the prediction of cardiopulmonanry complications with ADPS for EGD and colonoscopy. Methods: 243 patients undergoing routine EGD or colonoscopy with ADPS were prospectively studied. ASAPS was evaluated prior to the procedure by the staff anesthesiologist or nurse anesthetist involved in the procedure. AC were defined as a need for chin lift, mask ventilation, nasal airways, bag mask ventilation, or endotracheal intubation to be performed. SRC included hypoxemia (SPO2<90%), hypotension (SBP<25% of baseline), or early procedure termination due to sedation. Other variables such as age, gender, BMI, total propofol dose, history of pulmonary disease and use of opioids were also analyzed. A univariable and multivariable analysis was performed comparing ASAPS 1/2 vs. ASAPS 3 for AC and SRC outcomes. Results: Mean age was 50.1 ± 16.2 years and 41% of patients were male. ASAPS 1/2 (33.7%) and ASAPS 3 (66.3%) patients were included in the study. A univariable analysis revealed no significant difference between ASAPS 1/2 and ASAPS 3 patients in overall AC (42.7% vs. 49.7%, P=0.3) and SRC (30.5% vs. 29.2%, P=0.83). In a multivariable analysis, dichotomized ASAPS classification (1/2 vs. 3) was found not to exhibit an association with need of airway support after adjusting for total dose of propofol and propofol duration, BMI, history of lung disease, smoking and use of opioids. Two (2) ASAPS 3 patients required early procedure termination (1.3 vs. 0.0, P=0.31). Reversal agents were administer in one (1) ASAPS 3 patient (0.63 vs. 0.0, P=0.47). Conclusion: Higher ASAPS classification does not predict AC or SRC in patients undergoing routine EGD and colonoscopy with ADPS. This may indicate that longer time intervals under sedation with ADPS coupled with more complex procedures such as ERCP and EUS may play a role in predicting AC and SRC outcomes.