Outcome following inhalation anesthesia in birds at a veterinary referral hospital: 352 cases (2004-2014).

OBJECTIVE To determine the outcome in birds undergoing inhalation anesthesia and identify patient or procedure variables associated with an increased likelihood of anesthesia-related death. DESIGN Retrospective case series. ANIMALS 352 birds that underwent inhalation anesthesia. PROCEDURES Medical records of birds that underwent inhalation anesthesia from January 1, 2004, through December 31, 2014, at a single veterinary referral hospital were reviewed. Data collected included date of visit, age, species, sex, type (pet, free ranging, or wild kept in captivity), body weight, body condition score, diagnosis, procedure, American Society of Anesthesiologists status, premedication used for anesthesia, drug for anesthetic induction, type of maintenance anesthesia, route and type of fluid administration, volumes of crystalloid and colloid fluids administered, intraoperative events, estimated blood loss, duration of anesthesia, surgery duration, recovery time, recovery notes, whether birds survived to hospital discharge, time of death, total cost of hospitalization, cost of anesthesia, and nadir and peak values for heart rate, end-tidal partial pressure of carbon dioxide, concentration of inhaled anesthetic, and body temperature. Comparisons were made between birds that did and did not survive to hospital discharge. RESULTS Of 352 birds, 303 (86%) were alive at hospital discharge, 12 (3.4%) died during anesthesia, 15 (4.3%) died in the intensive care unit after anesthesia, and 22 (6.3%) were euthanatized after anesthesia. Overall, none of the variables studied were associated with survival to hospital discharge versus not surviving to hospital discharge. CONCLUSIONS AND CLINICAL RELEVANCE Results confirmed previous findings that indicated birds have a high mortality rate during and after anesthesia, compared with mortality rates published for dogs and cats.