Cardiopulmonary effects of a medetomidine-ketamine combination administered intravenously in gopher tortoises.
OBJECTIVE
To determine whether IV administration of a combination of medetomidine and ketamine depresses cardiopulmonary function in healthy adult gopher tortoises.


METHODS
Prospective study.


METHODS
3 adult male and 3 adult female nonreleasable gopher tortoises.


METHODS
Prior to the study, carotid and jugular catheters were surgically placed in each tortoise for blood collection, direct arterial blood pressure monitoring, and drug administration. Heart rate, direct carotid arterial blood pressure, and body temperature were measured before and every 5 minutes for 45 minutes after IV injection of medetomidine (100 microg/kg [45.5 microg/lb]) and ketamine (5 mg/kg [2.3 mg/lb]). Carotid arterial blood samples were collected before and 5, 15, 30, and 45 minutes after medetomidine-ketamine administration to determine pH, PO2, and PCO2. Atipamezole (500 mg/kg [227 microg/lb], IV) was administered 30 minutes after administration of medetomidine-ketamine.


RESULTS
The medetomidine-ketamine combination caused a moderate increase in arterial blood pressure, and moderate hypercapnia and hypoxemia. There were no significant changes in heart rate or body temperature. Intravenous administration of atipamezole rapidly induced severe hypotension.


CONCLUSIONS
The combination of medetomidine and ketamine administered IV resulted in effective short-term immobilization adequate for minor diagnostic procedures in gopher tortoises. This combination also caused moderate hypoventilation, and it is recommended that a supplemental source of oxygen or assisted ventilation be provided. Atipamezole administration hastens recovery from chemical immobilization but induces severe hypotension. It is recommended that atipamezole not be administered IV for reversal of medetomidine in tortoises and turtles.
Dennis
Patricia M
PM
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610, USA.
Heard
Darryl J
DJ
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000009:adverse effects; D019162:Anesthetics, Combined / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D000778:Anesthetics, Dissociative / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D007093:Imidazoles / Q000008:administration & dosage / Q000009:adverse effects; D007103:Immobilization; D007275:Injections, Intravenous / Q000662:veterinary; D007649:Ketamine / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D008297:Male; D020926:Medetomidine / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D010101:Oxygen Consumption; D011446:Prospective Studies; D012119:Respiration / Q000187:drug effects; D014426:Turtles / Q000502:physiology*
D000316:Adrenergic alpha-Agonists; D019162:Anesthetics, Combined; D000778:Anesthetics, Dissociative; D006993:Hypnotics and Sedatives; D007093:Imidazoles; C050701:atipamezole; D007649:Ketamine; D020926:Medetomidine