Increased Anesthesia Usage in a Large-Volume Endoscopy Unit: Patient Acuity Is Not the Main Predictor.

Objectives: The use of monitored anesthesia care (MAC) for colonoscopy sedation continues to increase. This study examined trends during a 9-year period in the use of MAC and explored which patient variables may have influenced these trends.

Methods: This was a retrospective review of all colonoscopies performed in our hospital-based endoscopy unit from 2003 through 2012. We determined whether MAC was used and if not, which quantitative doses of sedative agents were used. Several patient-related variables were evaluated for correlation. Data were analyzed (t test, χ(2), logistic regression) using SAS statistical software.

Results: Between January 2003 and October 2012, we identified 37,803 performed colonoscopies. The use of MAC increased significantly, from 0.38% in 2003 to 10.0% in 2012 (P < 0.0001). For cases in which conscious sedation was used, the mean doses of sedatives did not change significantly over time. Although there was an association between certain patient variables (female sex; higher American Society of Anesthesiologists class; diagnostic procedures; and pulmonary, psychiatric, renal or cerebrovascular diseases) and the use of MAC, the greatest predictor of MAC use was the year of the procedure. After adjusting for the patient variables that were examined, the odds of using MAC increased by approximately 1.5 times per year from 2003 through 2012. The adjusted odds of using MAC in 2012 were 35.8 times higher than in 2003.

Conclusions: The use of MAC for colonoscopies performed in our endoscopy unit increased significantly from 2003 to 2012. Although increased MAC use was associated with some patient variables, it was most significantly associated with the year of the procedure. This suggests that there were other nonpatient-related factors influencing its use.