Multivariable analysis of anesthetic factors associated with time to extubation in dogs

- Induction with propofol was associated with a shorter time to extubation.
- Premedication with acepromazine was associated with a longer time to extubation.
- Time to extubation was longer with higher body weights, lower body temperature, and longer anesthetic duration.

The purpose of this study was to identify factors that prolong the time to extubation in dogs. Anesthetic records of 900 dogs at a university teaching hospital were searched. Multiple linear regression was used to compare independent predictors (patient demographics, anesthetic and intraoperative variables) with the dependent variable (time to extubation). Induction with propofol (P < 0.025) was associated with a shorter time to extubation, while premedication with acepromazine (P = 0.000) was associated with a longer time to extubation. Time to extubation was increased by 0.311 minutes for every kilogram increase in body weight (P = 0.000), 5.924 minutes for every 1 °C loss in body temperature (P = 0.0000), and by 0.096 minutes for every 1 minute increase in anesthetic duration (P = 0.000). Anesthetic variables, which can be manipulated by the anesthetist, include choice of premedication and induction drugs, hypothermia, and duration of anesthesia.