Cardiopulmonary effects of medetomidine in sheep and in ponies.
Medetomidine was administered intravenously to six sheep at 5, 10 and 20 micrograms kg-1 and to one horse and four ponies at 5 and 10 micrograms kg-1. In both species medetomidine resulted in significant decreases in heart rate and cardiac output and, initially, in an increase in arterial blood pressure. In the ponies this increase in blood pressure was followed by a significant and prolonged decrease, but in the sheep the secondary decrease in blood pressure was not statistically significant. In the sheep, the three doses of medetomidine resulted in profound and significant decreases in arterial oxygen tensions, which were significantly dose related, but in the ponies the arterial blood oxygen tensions were not significantly decreased. In both species medetomidine caused a small but significant increase in arterial blood carbon dioxide tensions.
Bryant
C E
CE
Department of Large Animal Medicine and Surgery, Royal Veterinary College, North Mymms, Hatfield.
Clarke
K W
KW
Thompson
J
J
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006736:Horses; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D007093:Imidazoles / Q000008:administration & dosage / Q000494:pharmacology*; D007275:Injections, Intravenous; D020926:Medetomidine; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011652:Pulmonary Circulation / Q000187:drug effects; D012756:Sheep; D013997:Time Factors
D006993:Hypnotics and Sedatives; D007093:Imidazoles; D020926:Medetomidine; D010100:Oxygen