Alfaxan® as an Anaesthetic Agent for Total Intravenous Anaesthesia (TIVA): A Clinical Trial in Dogs in Urban and Remote Rural Settings
E.M. Tudor1; L.A. White2; B. O'Hagan3; T. Whittem3
The anaesthetic induction agent Alfaxan® has not previously been evaluated for induction and maintenance of anaesthesia by constant infusion (TIVA).
This study was designed to evaluate the efficacy and safety of Alfaxan® in a TIVA protocol in dogs.
Two cohorts of dogs were enrolled. The first was dogs being surgically desexed in a field setting in a remote aboriginal community. Following premedication with a premixed acepromazine, atropine and buprenorphine solution, anaesthesia was induced with Alfaxan, 2mg/kg administered intravenously over 60 seconds, and maintained by intravenous infusion using a syringe pump at a target rate of 7mg/kg. Dogs were intubated and spontaneously ventilated ambient air.
The second was enrolled at a suburban veterinary practice. Following similar premedication, the same Alfaxan TIVA protocol was used. Dogs were intubated, connected to an anaesthetic circuit and spontaneously ventilated 100% oxygen.
Induction, Anaesthetic Effectiveness and Recovery Scores were allocated using a previously described scoring system. ETCO2 (mmHg), SpO2 (%), heart rate, and respiratory rate were monitored throughout.
Average Induction, Anaesthetic Effectiveness and Recovery Scores were similar in both cohorts, with values correlating to acceptable for induction (3) and effectiveness (2.7) and good for recovery (3.2).
Physiological parameters were maintained within an acceptable range in all but two dogs in the suburban cohort, where apnoea and hypercapnia sufficient to warrant short periods of mechanical ventilation occurred.
Whilst supplemental oxygen should always be available, the findings suggest that an Alfaxan TIVA protocol provided acceptable cardiovascular, blood gas and respiratory parameters in dogs regardless of whether supplemental oxygen was administered.