Evaluation of selected cardiopulmonary and cerebral responses during medetomidine, propofol, and halothane anesthesia for laparoscopy in dogs.
OBJECTIVE
To compare the dose-sparing effect of medetomidine on the propofol induction dose and concentration of halothane for maintenance of anesthesia during laparoscopy and to provide guidelines for effective and safe use of these anesthetics in dogs to ensure desirable perioperative analgesia.


METHODS
14 purpose-bred dogs.


METHODS
Cardiopulmonary and electroencephalographic responses were determined during 2 anesthesia protocols in dogs scheduled for laparoscopy. Fifteen minutes before anesthesia induction, all dogs received atropine sulfate (0.02 mg/kg of body weight, i.m.). Seven dogs were then given propofol (6.6 mg/kg, i.v.); anesthesia was maintained with halothane in oxygen. The other dogs were given medetomidine hydrochloride (10 micrograms/kg, i.m.) 5 minutes after administration of atropine sulfate; anesthesia was then induced by administration of propofol (2.8 mg/kg, i.v.) and was maintained with halothane in oxygen.


RESULTS
The halothane concentration required for laparoscopy was lower in dogs given medetomidine. Anesthetic requirements were significantly increased during abdominal manipulation in both groups. Total amplitude of the electroencephalograph in medetomidine-treated dogs was not significantly lower than that in dogs not given medetomidine. Pulmonary responses were stable throughout all procedures. The primary cardiovascular response was an increase in blood pressure associated with the medetomidine-atropine preanesthetic combination. Significant differences in total amplitude or frequency shifts (spectral edge) of brain wave activity were not associated with surgical stimulation.


CONCLUSIONS
Lack of neurologic changes during laparoscopy supports the efficacy of either medetomidine-propofol-halothane or propofol-halothane combinations at higher concentrations to provide desirable analgesia and anesthesia in this group of dogs.
Bufalari
A
A
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853-6401, USA.
Short
C E
CE
Giannoni
C
C
Pedrick
T P
TP
Hardie
R J
RJ
Flanders
J A
JA
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000494:pharmacology; D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology; D019162:Anesthetics, Combined / Q000008:administration & dosage / Q000494:pharmacology*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000494:pharmacology; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001921:Brain / Q000187:drug effects* / Q000502:physiology; D002320:Cardiovascular Physiological Phenomena / Q000187:drug effects*; D004285:Dogs / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004569:Electroencephalography / Q000379:methods / Q000662:veterinary; D005260:Female; D006221:Halothane / Q000008:administration & dosage / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D007093:Imidazoles / Q000008:administration & dosage / Q000494:pharmacology*; D010535:Laparoscopy / Q000379:methods / Q000662:veterinary; D008297:Male; D020926:Medetomidine; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D017410:Practice Guidelines as Topic; D015742:Propofol / Q000008:administration & dosage / Q000494:pharmacology*; D011897:Random Allocation; D012143:Respiratory Physiological Phenomena; D012137:Respiratory System / Q000187:drug effects*
D000316:Adrenergic alpha-Agonists; D000700:Analgesics; D019162:Anesthetics, Combined; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D004338:Drug Combinations; D007093:Imidazoles; D020926:Medetomidine; D006221:Halothane; D015742:Propofol