Short Term Immobilization in the Horse with Ketamine HCl and Promazine HCl Combinations

Abstract

SUMMARY Combinations of promazine HCl and ketamine HCl were used to produce short term dissociative anaesthesia in the horse under normal clinical conditions. Premedication with 1 mg/kg promazine HCl followed 5 min later by a rapid i.v. injection of 2 mg/kg ketamine HCl, induced dissociative anaesthesia of 16 ±1 min. When 1 mg/kg promazine HCl and a 2 mg/kg ketamine HCl were given simultaneously by rapid i.v. injection, a state of dissociative anaesthesia was induced with a mean duration of 17.1 ±2 min. Both treatments permitted minor surgery in the horse. RÉSUMÉ L'association du chlorhydrate de promazine et du chlorhydrate de Kétamine a été utilisée pour provoquer une anesthésie de brève durée chez le cheval. La prémédication utilisant le chlorhydrate de promazine à raison de 1 mg par kilo était suivie 5 minutes plus tard par une injection rapide intraveineuse de 2 mg par kilo de chlorhydrate de kétamine: on obtint une anesthésie de 16 minutes environ. Par l'injection simultanée intraveineuse rapide de 1 mg de chlorhydrate de promazine et 2 mg de chlorhydrate de kétamine par kilo, l'anesthésie avait une durée moyenne de 17 minutes environ. Les deux méthodes permirent des interventions mineures. ZUSAMMENFASSUNG Kombinationen von Promazin‐ und Ketamin‐HCl wurden verwendet zur Erzeugung einer kurzdauernden dissoziativen Narkose beim Pferd unter normalen klinischen Bedingungen. Eine Praemedikation mit 1 mg/kg Promazin‐HCl, nach fünf Minuten gefolgt von einer schnellen intravenösen Injektion von 2 mg/kg Ketamin‐HCl, erzeugte eine 16 ± 1 Minuten dauernde dissoziative Anaesthesie. Wenn die beiden Praeparate in gleicher Dosierung zusammen rasch intravenös gegeben wurden, dauerte die resultierende Narkose 17.1 ±2 Minuten. Beide Methoden erlaubten die Durchführung kleinerer, chirurgischer Eingriffe.

Evaluation of the bispectral index as an indicator of degree of central nervous system depression in isoflurane-anesthetized horses

“…In our study, however, ketamine was probably no longer influencing BIS when anesthetized indices were recorded, because mean duration of action of ketamine administered at a dose of 2 mg/kg after promazine administered at a dose of 1 mg/kg is 23.8 minutes. 16 We believe that it is unlikely that the slight difference in effect of premedication and induction agents would override the effect of a 0.5% difference in end-tidal isoflurane concentration. Thus, we believe that the higher BIS in the 1.9% isoflurane group was an effect of isoflurane.…”

Methods of equine general anaesthesia in clinical practice

“…When combined with agents such as xylazine hydrochloride (Muir, Skarda and Milne 1977), xylazine hydrochloride and diazepam (Butera et a1 1978) and promazine hydrochloride (Fuentes 1978) it can provide reasonable short term anaesthesia (Table 1). When combined with agents such as xylazine hydrochloride (Muir, Skarda and Milne 1977), xylazine hydrochloride and diazepam (Butera et a1 1978) and promazine hydrochloride (Fuentes 1978) it can provide reasonable short term anaesthesia (Table 1).…”

“…The dissociative anaesthetic agent ketamine hydrochloride is another drug unsuitable for use on its own because of a number of side effects, particularly those affecting the extrapyramidal system. When combined with agents such as xylazine hydrochloride (Muir, Skarda and Milne 1977), xylazine hydrochloride and diazepam (Butera et a1 1978) and promazine hydrochloride (Fuentes 1978) it can provide reasonable short term anaesthesia (Table 1). However, the combination is very expensive if xylazine is used and does not provide good anaesthesia if adequate sedation is not achieved before ketamine is given or if the sedative effect wears off before the effects of ketamine do.…”

Chemical restraint in the horse

“…When promazine is used before ketamine, hyperacusia (increased sensitivity to noise) is also a feature (Fuentes 1978).…”