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Ketamine Dose Affects Minor Surgical Conditions and Recovery
Horses that received the higher dose of ketamine became relaxed more quickly after induction, and surgical conditions were better.
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A higher dose of IV ketamine may result in better surgical conditions than a lower dose, but appears to adversely affect recovery quality for field surgery, according to new research. Ketamine is frequently the anesthesia of choice for field surgeries, and researchers wanted to know if the dosing affected surgical conditions and recovery. In this prospective, randomized, blinded study, Hulda Harðardóttir and colleagues in the United Kingdom and Iceland compared 2 doses of ketamine (2.2 mg/kg and 5 mg/kg IV) for induction of anesthesia in 77 Icelandic horses undergoing field castration.
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Prior to induction, the horses were sedated with xylazine (0.7 mg/kg), butorphanol (25 μg/kg) and acepromazine (50 μg/kg) IV, and sedation quality was assessed 5 minutes later. Horses were allocated randomly 1 of the 2 ketamine doses and induced with IV ketamine and diazepam (30 μg/kg). Induction quality, surgical conditions and recovery were assessed using subjective and objective measures. Horses that received the higher dose of ketamine became relaxed more quickly after induction, and surgical conditions were better; however, recovery quality was subjectively worse, but no adverse events were observed. Five horses that received the lower dose of ketamine required additional ketamine doses during anesthesia compared with only 2 that received the higher dose. MeV
For more information: Harðardóttir H, Murison PJ, Blissitt K, et al. A comparison of two ketamine doses for field anesthesia in horses undergoing castration. Equine Vet J 2018 Nov. 24 [Epub ahead of print]). https://onlinelibrary.wiley.com/doi/pdf/10.1111/evj.13052
www.shanksvet.com • info@shanksvet.com ModernEquineVet.com | Issue 12/2018
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