Hemodynamic and analgesic effects of propofol infusion in medetomidine-premedicated dogs.
Hemodynamic and analgesic effects of medetomidine (30 micrograms/kg of body weight, IM), atropine (0.044 mg/kg, IM), and propofol (2 mg/kg, IV, as a bolus, and 165 micrograms/kg/min, IV, for 60 minutes, as an infusion) were evaluated in 6 healthy adult Beagles. Catheters were placed while the dogs were anesthetized with isoflurane in oxygen. Administration of isoflurane was then discontinued, and dogs were allowed to breath oxygen until end-tidal isoflurane concentration was < or = 0.5%. At this time, baseline measurements were recorded and medetomidine and atropine were administered. Ten minutes later, the bolus of propofol was given and the infusion was begun. Analgesia was evaluated with a tail clamp test and by use of a direct-current nerve stimulator. Sinoatrial and atrioventricular blockade developed in all 6 dogs within 2 minutes of administration of medetomidine and atropine, but disappeared within 10 minutes. Apnea did not develop after administration of propofol. Analgesia was strong and consistent throughout the entire 60-minute period of propofol infusion. Medetomidine significantly (P < 0.05) increased systemic vascular resistance and decreased cardiac output, compared with baseline values. Propofol infusion appeared to alleviate medetomidine-induced vasoconstriction. Recovery was smooth and uncomplicated. All dogs were able to walk normally at a mean time (+/- SEM) of 88.2 +/- 20.6 minutes after termination of propofol infusion. It was concluded that medetomidine, atropine, and propofol, as given in the present study, is a safe combination of anesthetic drugs for use in healthy Beagles.
Thurmon
J C
JC
Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana 61801.
Ko
J C
JC
Benson
G J
GJ
Tranquilli
W J
WJ
Olson
W A
WA
D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D002302:Cardiac Output / Q000187:drug effects; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology*; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D008297:Male; D020926:Medetomidine; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011292:Premedication; D015742:Propofol / Q000008:administration & dosage / Q000494:pharmacology*; D011651:Pulmonary Artery / Q000187:drug effects / Q000502:physiology; D011652:Pulmonary Circulation / Q000187:drug effects; D012119:Respiration / Q000187:drug effects
D000700:Analgesics; D007093:Imidazoles; D002245:Carbon Dioxide; D001285:Atropine; D020926:Medetomidine; D010100:Oxygen; D015742:Propofol