Anesthesia Recovery in Dogs

General anesthesia in dogs is associated with common complications such as paddling and vocalizing, but significant perioperative mortality is seen as well (0.17%). Factors that prolong anesthetic recovery and time to extubation may increase risk. This retrospective study identified factors affecting recovery time and quality in 900 dogs undergoing general anesthesia with a volatile anesthetic or propofol infusion. Variables examined included patient signalment, diagnosis, American Society of Anesthesiologist (ASA) status, premedication and induction drugs used, maintenance agents, duration of anesthesia and surgery, body temperature nadir, end-tidal inhalant concentration, blood pressure nadir, intraoperative drugs given, and time to extubation. Multiple regression analysis was performed. Results showed premedication with acepromazine significantly increased time to extubation by 7.9 minutes. Induction with propofol was associated with decreased time to extubation. Hypothermia, higher body weight, and anesthetic duration were all associated with longer times to extubation. Time to extubation increased by 5.924 minutes for every 1oC loss in body temperature, and 5.8 minutes for every 1-hour increase in anesthesia time. The authors conclude that controllable factors (eg, choice of premedication and induction drugs, hypothermia, duration of anesthesia) can affect anesthetic recovery times.

This clinically relevant study provides sound evidence for clinical situations that veterinarians face on a daily basis. In reality, prevention and treatment of hypothermia is crucial to reduce anesthetic recovery time. On a different perspective, acepromazine may delay but improve anesthetic recovery. The drug is commonly administered to treat opioid-induced dysphoria or emergence delirium. The study also makes an important point on how short anesthetic duration is important for a rapid recovery and return to normal cardiopulmonary function. Anesthetic induction with propofol was associated with rapid extubation. Alfaxalone might provide similar benefits.—Paulo Steagall, MV, MSc, PhD, DACVAA (Montreal, Canada)

This capsule is part of the WSAVA Global Edition of Clinician's Brief.