Post-anesthetic hyperthermia in cats.
OBJECTIVE
To assess whether administration of hydromorphone and, or ketamine are associated with post-anesthetic hyperthermia in cats undergoing routine surgery.


METHODS
Prospective clinical study.


METHODS
Forty healthy, adult cats undergoing ovariohysterectomy (OVH), castration, or declaw surgery.


METHODS
Each cat was assigned randomly to one of four groups (n = 10). For pre-anesthetic medication, all cats received subcutaneous (SC) glycopyrrolate (0.01 mg kg(-1)) and acepromazine (0.02 mg kg(-1)) and either hydromorphone (0.1 mg kg(-1) SC) or medetomidine (7.5 microg kg(-1) SC). Anesthesia was induced with either diazepam (0.1 mg kg(-1)) and ketamine (5 mg kg(-1)) or propofol (6 mg kg(-1) injected to effect). Group 1 (HDK) received hydromorphone and diazepam-ketamine. Group 2 (HP) received hydromorphone and propofol. Group 3 (MDK) received medetomidine and diazepam-ketamine. Group 4 (MP) received medetomidine and propofol. Rectal temperature was measured before drugs were given, at tracheal extubation and at hourly intervals for 5 hours thereafter.


RESULTS
During the 5 hours after anesthesia and surgery, at least one cat in every group had a rectal temperature >39.2 degrees C (102.5 degrees F). The percentage of observations for which a cat's temperature exceeded its pre-anesthetic temperature in groups HDK, HP, MDK, and MP were 86%, 80%, 25%, and 34%, respectively. Maximum temperatures in groups HDK, HP, MDK, and MP were 41.6 degrees C (107.0 degrees F), 40.3 degrees C (104.2 degrees F), 39.2 degrees C (102.6 degrees F), and 40.1 degrees C (104.1 degrees F), respectively. By 5 hours after tracheal extubation there were no differences in temperature between the treatment groups.


CONCLUSIONS
For up to 5 hours following anesthesia and surgery, cats might have body temperatures that exceed their pre-anesthesia body temperatures. The use of hydromorphone is associated with post-anesthetic hyperthermia. However, hyperthermia may occur when other drugs are used.


CONCLUSIONS
Cats given hydromorphone should be closely monitored for hyperthermia following anesthesia and surgery.
Posner
Lysa P
LP
Department of Clinical Sciences, VMC College of Veterinary Medicine, Cornell University, Ithaca, NY, USA. lysa_posner@ncsu.edu
Gleed
Robin D
RD
Erb
Hollis N
HN
Ludders
John W
JW
D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects*; D000762:Anesthesia Recovery Period; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D002371:Cat Diseases / Q000139:chemically induced*; D002415:Cats; D005260:Female; D005334:Fever / Q000139:chemically induced / Q000662:veterinary*; D004091:Hydromorphone / Q000009:adverse effects*; D007649:Ketamine / Q000009:adverse effects*; D008297:Male; D020926:Medetomidine / Q000009:adverse effects; D015742:Propofol / Q000009:adverse effects
D000701:Analgesics, Opioid; D007649:Ketamine; D020926:Medetomidine; D004091:Hydromorphone; D015742:Propofol