Effect of ketorolac tromethamine on atracurium-induced neuromuscular blockade in anesthetized dogs.
OBJECTIVE
The purpose of this study was to determine the effect of ketorolac tromethamine or placebo on the neuromuscular blockade induced by an infusion of atracurium in isoflurane-anesthetized dogs.


METHODS
Randomized, controlled trial.


METHODS
Six healthy, adult mixed-breed dogs (five female, one male) weighing 24.8 +/- 2.8 kg.


METHODS
Dogs were studied on two occasions with a minimum of 7 days between studies. Dogs were induced with 5% isoflurane in oxygen and maintained with 1.6 x minimum alveolar concentration (MAC) end-tidal isoflurane. Neuromuscular blockade was assessed using the train-of-four response. Once 50% depression of the first twitch (T1) was achieved, the atracurium infusion rate was held constant for 30 minutes. Then ketorolac, 0.5 mg/kg, or the same volume of placebo (0.9% sodium chloride solution) was administered intravenously and the atracurium infusion maintained for an additional 60 minutes. Before and at 2, 5, 10, 15, 30, and 60 minutes after ketorolac or placebo, the percent depression of T1 and the fourth twitch to the first twitch (T4/T1) ratio were recorded. The atracurium infusion was discontinued and the time for T1 to recover from 50% to 75% of its original value was recorded. At 75% T1, edrophonium, 0.5 mg/kg intravenously, was administered to antagonize the residual blockade.


RESULTS
There was no significant difference in T1%, T4/T1 ratio, or recovery time after ketorolac administration compared with placebo.


CONCLUSIONS
Ketorolac, 0.5 mg/kg intravenously, has no significant effect on either atracurium-induced neuromuscular blockade or recovery time for T1 in isoflurane-anesthetized dogs.


CONCLUSIONS
The concurrent use of atracurium should not be a contraindication for the administration of ketorolac for intraoperative or postoperative analgesia.
Martinez
E A
EA
Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M University, College Station 77843-4474, USA.
Wooldridge
A A
AA
Hartsfield
S M
SM
D000280:Administration, Inhalation; D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology*; D018685:Anesthetics, Inhalation; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000494:pharmacology*; D001279:Atracurium / Q000008:administration & dosage / Q000494:pharmacology*; D004285:Dogs / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D007262:Infusions, Intravenous / Q000662:veterinary; D007530:Isoflurane; D020911:Ketorolac Tromethamine; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D019148:Neuromuscular Blockade; D013997:Time Factors; D014046:Tolmetin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D014325:Tromethamine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology
D000700:Analgesics; D018685:Anesthetics, Inhalation; D000894:Anti-Inflammatory Agents, Non-Steroidal; D014325:Tromethamine; D001279:Atracurium; D020911:Ketorolac Tromethamine; D007530:Isoflurane; D014046:Tolmetin