Neuromuscular and cardiovascular effects of pancuronium bromide in calves anesthetized with halothane.
Pancuronium bromide was administered to calves to define the dosage level necessary to produce surgical relaxation (90% to 99% reduction of base-line evoked, hindlimb digital-extensor muscle twitch tension). Initial dosage level requirement was 43 +/- 9 micrograms/kg of body weight. Calves with this degree of relaxation required 26 +/- 14 minutes to achieve 50% recovery and 43 +/- 19 minutes to achieve complete return of base-line muscle twitch. Calves given a repeat injection of pancuronium at base-line muscle twitch required 27 +/- 9 micrograms/kg to achieve relaxation similar to that of the 1st dose. The 2nd dose did not last as long as the 1st, with complete recovery occurring in 37 +/- 12 minutes. Maximum evoked tension occurred at 200- to 400-g resting tension on the hoof. There was an absence of heart rate or blood pressure changes after injection of relaxant and a variable and inconsistent fade response to train-of-four and tetanic stimulus of the facial muscles. Acid-base values were alkalemic (pHa 7.5 +/- 0.08) when ventilation was controlled at eucapnia (PaCO2, 25 to 45 mm of Hg).
D000768:Anesthesia, General / Q000662:veterinary*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects*; D002417:Cattle / Q000502:physiology*; D005071:Evoked Potentials / Q000187:drug effects; D006221:Halothane; D006614:Hindlimb; D009119:Muscle Contraction / Q000187:drug effects; D009132:Muscles / Q000187:drug effects*; D010197:Pancuronium / Q000494:pharmacology*
D010197:Pancuronium; D006221:Halothane