Effects of atracurium administered by continuous intravenous infusion in halothane-anesthetized horses.
Atracurium (0.4 mg/ml in isotonic NaCl solution) was administered by IV infusion to 7 healthy adult horses for 2 hours. Over the 2-hour period, a 95 to 99% reduction of train-of-four hoof-twitch response was maintained by 0.17 +/- 0.01 mg of atracurium/kg of body weight/h, for a total of 161 +/- 6 mg of atracurium (mean +/- SEM) for horses 1 to 4, 6, and 7. Horse 5, a mare in estrus, required 0.49 mg of atracurium/kg/h to maintain comparable relaxation. Hoof-twitch recovery time from 10 to 75% of baseline strength was 19.8 +/- 2.5 minutes for all horses. The 10 to 75% recovery time for horse 5 was 18 minutes. Recovery time from discontinuation of halothane until standing was 86 +/- 14 minutes (range, 55 to 165 minutes). Horse 5 had a 165-minute recovery. Regarding recovery from anesthesia, 3 recoveries were rated as excellent, 1 recovery good, and 2 recoveries as fair. Horse 5 laid quietly until she stood with 1 strong, smooth effort.
Hildebrand
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SV
Department of Surgery, School of Veterinary Medicine, University of California, Davis 95616.
Hill
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D000762:Anesthesia Recovery Period; D000818:Animals; D001279:Atracurium / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006221:Halothane; D006614:Hindlimb / Q000294:innervation; D006724:Hoof and Claw / Q000294:innervation; D006736:Horses / Q000502:physiology*; D007262:Infusions, Intravenous / Q000662:veterinary; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects*; D012018:Reflex; D013997:Time Factors
D001279:Atracurium; D006221:Halothane