Effects of dopamine and dobutamine on isoflurane-induced hypotension in Hispaniolan Amazon parrots (Amazona ventralis).
OBJECTIVE
To assess the effects of dopamine and dobutamine on the blood pressure of isoflurane-anesthetized Hispaniolan Amazon parrots (Amazona ventralis).


METHODS
8 Hispaniolan Amazon parrots.


METHODS
A randomized crossover study was conducted. Each bird was anesthetized (anesthesia maintained by administration of 2.5% isoflurane in oxygen) and received 3 doses of each drug during a treatment period of 20 min/dose. Treatments were constant rate infusions (CRIs) of dobutamine (5, 10, and 15 μg/kg/min) and dopamine (5, 7, and 10 μg/kg/min). Direct systolic, diastolic, and mean arterial pressure measurements, heart rate, esophageal temperature, and end-tidal partial pressure of CO(2) were recorded throughout the treatment periods.


RESULTS
Mean ± SD of the systolic, mean, and diastolic arterial blood pressures at time 0 (initiation of a CRI) were 132.9 ± 22.1 mm Hg, 116.9 ± 20.5 mm Hg, and 101.9 ± 22.0 mm Hg, respectively. Dopamine resulted in significantly higher values than did dobutamine for the measured variables, except for end-tidal partial pressure of CO(2). Post hoc multiple comparisons revealed that the changes in arterial blood pressure were significantly different 4 to 7 minutes after initiation of a CRI. Overall, dopamine at rates of 7 and 10 μg/kg/min and dobutamine at a rate of 15 μg/kg/min caused the greatest increases in arterial blood pressure.


CONCLUSIONS
Dobutamine CRI at 5, 10, and 15 μg/kg/min and dopamine CRI at 5, 7, and 10 μg/kg/min may be useful in correcting severe hypotension in Hispaniolan Amazon parrots caused by anesthesia maintained with 2.5% isoflurane.
Zoological Medicine Service, Department of Small Animal Medicine, College of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA. schnell@uga.edu
Rodney W
RW
Schnellbacher
Anderson F
AF
da Cunha
Hugues
H
Beaufrère
Patricia
P
Queiroz
Javier G
JG
Nevarez
Thomas N
TN
Tully
D058665:Adrenergic beta-1 Receptor Agonists / Q000494:pharmacology*; D046708:Amazona / Q000502:physiology*; D000758:Anesthesia / Q000009:adverse effects*; D000818:Animals; D001715:Bird Diseases / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D004280:Dobutamine / Q000494:pharmacology*; D004298:Dopamine / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D007022:Hypotension / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology / Q000662:veterinary*; D016018:Least-Squares Analysis; D011897:Random Allocation
D058665:Adrenergic beta-1 Receptor Agonists; D004280:Dobutamine; D004298:Dopamine