Pharmacokinetics and anesthetic and cardiopulmonary effects of propofol in red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus).
OBJECTIVE
To determine induction doses, anesthetic constant rate infusions (CRI), and cardiopulmonary effects of propofol in red-tailed hawks and great horned owls and propofol pharmacokinetics in the owls during CRI.


METHODS
6 red-tailed hawks and 6 great horned owls.


METHODS
The CRI dose necessary for a loss of withdrawal reflex was determined via specific stimuli. Anesthesia was induced by IV administration of propofol (1 mg/kg/min) and maintained by CRI at the predetermined dose for 30 minutes. Heart and respiratory rates, arterial blood pressures, and blood gas tensions were obtained in awake birds and at various times after induction. End-tidal CO2 (ETCO2) concentration and esophageal temperature were obtained after induction. Propofol plasma concentrations were obtained after induction and after completion of the CRI in the owls. Recovery times were recorded.


RESULTS
Mean +/- SD doses for induction and CRI were 4.48 +/- 1.09 mg/kg and 0.48 +/- 0.06 mg/kg/min, respectively, for hawks and 3.36 +/- 0.71 mg/kg and 0.56 +/- 0.15 mg/kg/min, respectively, for owls. Significant increases in PaCO2, HCO3, and ETCO2 in hawks and owls and significant decreases in arterial pH in hawks were detected. A 2-compartment model best described the owl pharmacodynamic data. Recovery times after infusion were prolonged and varied widely. Central nervous system excitatory signs were observed during recovery.


CONCLUSIONS
Effects on blood pressure were minimal, but effective ventilation was reduced, suggesting the need for careful monitoring during anesthesia. Prolonged recovery periods with moderate-to-severe excitatory CNS signs may occur in these species at these doses.
Hawkins
Michelle G
MG
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis 95616, USA.
Wright
Bonnie D
BD
Pascoe
Peter J
PJ
Kass
Philip H
PH
Maxwell
Lara K
LK
Tell
Lisa A
LA
D000758:Anesthesia / Q000009:adverse effects / Q000662:veterinary*; D018686:Anesthetics, Intravenous / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000494:pharmacology*; D000818:Animals; D001639:Bicarbonates / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D010100:Oxygen / Q000097:blood; D015742:Propofol / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000494:pharmacology*; D020304:Raptors; D012119:Respiration / Q000187:drug effects; D013045:Species Specificity
D018686:Anesthetics, Intravenous; D001639:Bicarbonates; D002245:Carbon Dioxide; D010100:Oxygen; D015742:Propofol