The effect of adding butorphanol tartrate to an acepromazine maleate premedicant on anaesthetic induction and recovery in dogs
Abstract
This study evaluated the inclusion of butorphanol to an acepromazine maleate (ACP) premedication in 20 healthy bitches undergoing elective ovariohysterectomy to determine whether this was beneficial in improving the practice's premedication protocol. Ten bitches were administered ACP (0.04 mg/kg) and ten bitches were administered ACP (0.01 mg/kg) and butorphanol (0.01 mg/kg); both groups received carprofen (4 mg/kg). Anaesthesia was induced with propofol (4 mg/kg) to effect and was maintained on isoflurane. The time of extubation, sternal recumbency and standing was recorded, and pain scores were completed at 0, 1, 2, 3 and 24 hours. The volume of propofol required to induce anaesthesia was also recorded. Owners completed a questionnaire regarding the bitch's behaviour post operatively. It was concluded that the addition of butorphanol to an ACP premedication significantly increases the time for the bitch to regain sternal recumbency and to stand (p=0.017); all other differences in effects and observations between the two groups were statistically insignificant.
In all but very few cases a premedication is administered to the patient undergoing anaesthesia and it is vital that the veterinary nurse has a thorough understanding of the premedication protocol used. The premedication chosen will ultimately have effects on the anaesthesia and analgesia protocols used. The aims of premedication are to sedate the animal, produce anxiolysis, contribute to balanced anaesthesia, provide analgesia and help achieve a smooth and uneventful recovery (Kojima et al, 2002; Grant, 2006; Murrell, 2007). Inclusion of an analgesic drug contributes to pre-emptive analgesia. The prevention of pain is important as the veterinary profession has a moral, ethical and medical obligation to treat pain (Viñuela-Fernádez et al, 2007).
Acepromazine maleate (ACP) (Novartis Animal Health, Surrey, UK) is a phenothiazine and an α-antagonist (Murrell, 2007; Carroll, 2008). It is the most commonly used drug of this group for small animal premedication in the UK (Hall et al, 2001; Flaherty, 2003; Murrell, 2007; Posner and Burns, 2009) and produces mild to moderate sedation in dogs (Monteiro et al, 2009). The dose range for ACP is 0.01–0.05 mg/kg for dogs (Flaherty, 2003; Murrell, 2007) and it has been used to reduce anaesthetic induction agent requirements (Bufalari et al, 1997). At lower doses, tranquilization can be achieved and there are sedative effects at the higher doses. If tranquilization is not achieved at lower doses, increasing the dose will only contribute to intensifying adverse effects (Rock, 2007) and prolonging the duration of action (Murrell, 2007). ACP is protective against catecholamine-induced arrhythmias (Murrell, 2007) and has antiemetic effects (Flaherty, 2003).
Register now to continue reading
Thank you for visiting The Veterinary Nurse and reading some of our peer-reviewed content for veterinary professionals. To continue reading this article, please register today.