Influence of ketamine or midazolam in combination with a romifidine-butorphanol-constant rate infusion on sedation quality during tooth extraction in standing horses

Einfluss von Ketamin oder Midazolam in Kombination mit einer Dauertropfinfusion von Romifidin und Butorphanol auf die Sedierungsqualität während Zahnextraktionen am stehenden Pferd

Hopster K, Bienert-Zeit A, Hopster-Iversen C, Kästner S

DOI: 10.21836/PEM20130209
Year: 2013
Volume: 29
Issue: 2
Pages: 220 - 227

The study was performed to evaluate the influence of the addition of either ketamine or midazolam to a romifidine-butorphanol bolus followed by a constant rate infusion (CRI) on the quality of sedation during tooth extraction in horses. Forty-five client-owned horses presented for dental pathologies were randomly assigned to one of 3 groups. Horses in group RB received a bolus of 0.03 mg/kg IV romifidine and 0.01 mg/kg IV butorphanol followed by a CRI of 0.04 mg/kg/h romifidine and 0.02 mg/kg/h butorphanol. Horses in group RBK received a bolus of romifidine and butorphanol in the same dosage and an additional bolus of 0.5 mg/kg IV ketamine followed by a CRI of 0.04 mg/kg/h romifidine, 0.02 mg/kg/h butorphanol and 1.2 mg/kg/h ketamine. Horses in group RBM received the same bolus of romifidine and butorphanol and an additional bolus of 0.02 mg/kg IV midazolam followed by a CRI of 0.04 mg/kg/h romifidine, 0.02 mg/kg/h butorphanol and 0.06 mg/kg/h midazolam. Heart rate, respiratory rate, degree of ataxia, fighting against the mouth speculum, chewing during manipulation, head-shaking, movement of the tongue, overall sedation quality and additional top up boli of 0.01 mg/kg bwt romifidine necessary to provide adequate sedation were recorded every ten minutes. To provide adequate sedation horses in group RB needed 4.2±3, in group RBK 1.4±0.5 and in group RBM 2±1.1 (mean±SD) additional boli of romifidine. Horses in group RBM had a higher degree of ataxia than horses in group RB but head-slapping was significant less in theses horses when compared to horses in group RB. There were significant less fighting against the mouth speculum, chewing during manipulation and movement of the tongue and in horses in group RBK and RBM when compared to group RB and overall sedation quality and extraction quality was better in these horses. Results of this study showed that sedation quality was improved and less romifidine was needed when adding ketamine or midazolam to a romifidine-butorphanol based sedation protocol. Further studies are necessary to see whether there would be an additional benefit when combining both drugs.