Cardiovascular effects of orotracheal intubation following anesthetic induction with propofol, ketamine-propofol, or ketamine-diazepam in premedicated dogs.
OBJECTIVE
To compare the hemodynamic responses to orotracheal intubation following induction of anesthesia with propofol, ketamine-propofol, and ketamine-diazepam in premedicated dogs.


METHODS
Prospective, randomized, masked study.


METHODS
10 healthy adult Beagles.


METHODS
Dogs were randomly allocated to be anesthetized twice, with a 1-week wash-out interval, by means of 2 of 3 possible protocols (propofol [4 mg/kg {1.8 mg/lb}, n = 6 dogs], ketamine [2 mg/kg {0.9 mg/lb}] and propofol [2 mg/kg; 7], or ketamine [5 mg/kg {2.3 mg/lb}] and diazepam [0.2 mg/kg {0.09 mg/lb}; 6]). After instrumentation, continuous heart rate, systolic arterial blood pressure, mean arterial blood pressure, diastolic arterial blood pressure, cardiac index, stroke volume index, and systemic vascular resistance were recorded. Fifteen minutes after premedication, dogs were anesthetized; all anesthetics were administered IV. After 5 minutes, orotracheal intubation was performed without the use of a laryngoscope. Data were collected prior to intubation (baseline), at intubation, and 30, 60, 90, 120, 150, and 180 seconds thereafter. Results were compared among the 3 groups and over time.


RESULTS
No differences among groups were observed for any variables studied. In all groups, arterial blood pressures were significantly decreased at various time points after intubation. A significant increase in systolic arterial blood pressure was observed between baseline and the 30-second time point in the ketamine-diazepam group. No significant differences were detected over time for the other variables in any group.


CONCLUSIONS
Intubation after anesthetic induction with ketamine-diazepam caused transitory hypertension, whereas intubation after induction with propofol or ketamine-propofol did not cause cardiovascular stimulation. In dogs in which hypertension is a concern, propofol or ketamine-propofol may be a better choice for induction prior to orotracheal intubation.
Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061.
Carolina H
CH
Riccó
Natalia
N
Henao-Guerrero
D000778:Anesthetics, Dissociative / Q000008:administration & dosage / Q000494:pharmacology; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D018592:Cross-Over Studies; D003975:Diazepam / Q000008:administration & dosage / Q000494:pharmacology*; D004285:Dogs; D004311:Double-Blind Method; D007440:Intubation / Q000662:veterinary*; D007649:Ketamine / Q000008:administration & dosage / Q000494:pharmacology*; D015742:Propofol / Q000008:administration & dosage / Q000494:pharmacology*
D000778:Anesthetics, Dissociative; D018686:Anesthetics, Intravenous; D007649:Ketamine; D003975:Diazepam; D015742:Propofol