Cardiovascular and respiratory effects, and quality of anesthesia produced by alfaxalone administered intramuscularly to cats sedated with dexmedetomidine and hydromorphone

Abstract

The cardiovascular and respiratory effects, and the quality of anesthesia of alfaxalone administered intramuscularly (IM) to cats sedated with dexmedetomidine and hydromorphone were evaluated. Twelve healthy adult cats were anesthetized, with six cats receiving dexmedetomidine (0.01 mg/kg IM) followed by alfaxalone (5 mg/kg IM; group DA) and six receiving dexmedetomidine (0.01 mg/kg IM) plus hydromorphone (0.1 mg/kg IM) followed by alfaxalone (5 mg/kg IM; group DHA). Cardiorespiratory (pulse rate, blood pressure, respiratory rate, saturation of oxygen with hemoglobin, end tidal carbon dioxide partial pressure) and bispectral index (BIS) data were collected every 10 mins for 90 mins starting immediately after intubation. The quality of anesthesia was scored by a blinded researcher at induction and at 5 and 60 mins after extubation. Recovery scores ranged from 1 (prolonged struggling) to 4 (no struggling). There were no clinically significant (P >0.05) differences in any data between groups or over time. Physiologic parameters were within normal limits for cats at all times. BIS values were consistent with light anesthesia in both groups. However, recovery was prolonged and marked with excitement, ataxia and hyper-reactivity in all cats. Thus, although cardiovascular and respiratory parameters are stable following IM injection of alfaxalone to cats sedated with dexmedetomidine and hydromorphone, recovery is extremely poor and this route of administration is not recommended for anesthesia in cats.

The safety, efficacy and neuromotor effects of the neurosteroid anaesthetic alfaxalone in rats

“…Medetomidine and medetomidinebutorphanol premedication however dropped SpO 2 levels below 90%. A recent study showed that cats given IM alfaxalone anaesthesia maintained SpO 2 levels above 85% the majority of time whilst breathing room air (Grubb et al, 2013). The addition of the α 2 -adrenergic agonists, xylazine or medetomidine appeared to be associated with respiratory depression, consistent with the reduction in SpO 2 levels with these premedications.…”

“…For the remainder of the rats, anaesthetic recovery was uneventful. Our rat pharmacokinetic study demonstrated that 20 mg.kg -1 IP alfaxalone produced sustained plasma levels of alfaxalone for up to 60 minutes (Lau et al, 2013 (Grubb et al, 2013). Even though the anaesthetic effects of alfaxalone was unpredictable, we could see that alfaxalone had a wide margin of safety, as shown by the three fold increase in dose in these preliminary trials, and we were therefore keen to pursue an effective alfaxalone anaesthetic protocol by combination with other commonly used anaesthetic premedications.…”

“…properties (Guarnieri et al, 2012). Bupenorphine can be administered subcutaneously or orally in rats and mice (Liles and Flecknell, 1992a, Volker et al, 2000, Abelson et al, 2012 and has shown to be effective in treating multiple pain conditions including neuropathic pain (Guarnieri et al, 2012).…”

“…Bupenorphine can be administered subcutaneously or orally in rats and mice (Liles and Flecknell, 1992a, Volker et al, 2000, Abelson et al, 2012 and has shown to be effective in treating multiple pain conditions including neuropathic pain (Guarnieri et al, 2012). Preanaesthetic subcutaneous (SC) administration of buprenorphine, during ketamine-medetomidine injectable anaesthesia, was associated with respiratory arrest and mortality in rats (Hedenqvist et al, 2000).…”

O Uso De Alfaxalona Em Pequenos Animais

“…No entanto, outros autores indicam a necessidade de mais estudos para avaliar o motivo da dor, se pelo volume, ou a lesão pela agulha, ou irritação local do fármaco (KHENISSI et al, 2017). Estudo em gatos demonstrou que a alfaxalona pela via intramuscular, na dose de 5,0 mg/kg, resulta em níveis de índice biespectral comparáveis aos de uma anestesia inalatória leve, e os mesmos se mantém reativos aos sons durante a anestesia (GRUBB et al, 2013).…”