Predicting the risk of sedation related complications in private endoscopy units

Abstract

Introduction: Endoscopic facilities may be hospital-based or stand-alone day-procedure units, and sedation may be provided by non-specialist or specialist anesthetists, proceduralists, or even nurses under supervision. It is vital that patient characteristics that may influence the safety of sedation be assessed prior to the procedure. Body mass index (BMI) may be one such factor. Obesity is increasingly becoming more prevalent in the Australian population. The most recent Australian Bureau of Statistics data shows that 35.5% of the population is overweight and 27.9% are classified as obese. We report on the effect of BMI and other patient characteristics on sedation safety at two private endoscopy day procedure units in Canberra. Methods: Information was collected prospectively for all patients over a 6-month timeframe and recorded by nursing staff at the time of the procedure. Basic patient demographics, underlying respiratory conditions, sedative agents, and complications were recorded in a de-identified database. Every patient received a phone review the day after their procedure to ensure all immediate complications were identified. Results: A total of 1557 patients were included in the study. BMI ranged from 15.2 to 53.5. There were 43 minor complications recorded but no severe complications requiring hospitalization. Eighteen complications were related to airway compromise, 21 to pain/nausea, 2 to IV fluids being required, and 2 were exacerbations of asthma. Of the airway complications, 12 required an oropharyngeal airway, 5 required bag-valve-mask support, and 1 required both. There was an increasing proportion of complications as BMI increased, with 2.3% of the normal population, 3.1% of the overweight (BMI 25–29.9), 2.6% obesity class 1 (BMI 30–34.9), 3.7% obesity class 2 (BMI 35–39.9), and 7.1% obesity class 3 (BMI ≥40) having complications. Respiratory complications occurred in 0.8% of the normal population, 0.8% of the overweight, 1.8% obesity class 1, 2.5% obesity class 2, and 7.1% obesity class 3. There were no complications in the underweight group. Snoring was also found to be more prevalent in the group that experienced complications, with 24 out of 43 patients (56%) being snorers. This result reached statistical significance (P = 0.0029). Conclusion: We found there to be a positive trend for developing any complication with endoscopic procedures as BMI increased, with BMI ≥ 40 being a major indicator. This trend was also present for respiratory complications specifically but due to the small numbers, these results did not reach statistical significance. However, there was a statistically significant increase in complications in snorers which may be a predictor. These results have important implications for the private sector to stratify risk for patients having endoscopic procedures outside teaching hospitals.