A comparison of cardiopulmonary and anesthetic effects of an induction dose of alfaxalone or propofol in dogs.

OBJECTIVE

To compare the physiological parameters, arterial blood gas values, induction quality, and recovery quality after IV injection of alfaxalone or propofol in dogs.

STUDY

DESIGN

Prospective, randomized, blinded crossover.

ANIMALS: Eight random-source adult female mixed-breed dogs weighing 18.7 ± 4.5 kg.

METHODS

Dogs were assigned to receive up to 8 mg kg(-1) propofol or 4 mg kg(-1) alfaxalone, administered to effect, at 10% of the calculated dose every 10 seconds. They then received the alternate drug after a 6-day washout. Temperature, pulse rate, respiratory rate, direct blood pressure, and arterial blood gases were measured before induction, immediately post-induction, and at 5-minute intervals until extubation. Quality of induction, recovery, and ataxia were scored by a single blinded investigator. Duration of anesthesia and recovery, and adverse events were recorded.

RESULTS

The mean doses required for induction were 2.6 ± 0.4 mg kg(-1) alfaxalone and 5.2 ± 0.8 mg kg(-1) propofol. After alfaxalone, temperature, respiration, and pH were significantly lower, and PaCO2 significantly higher post-induction compared to baseline (p < 0.03). After propofol, pH, PaO2 , and SaO2 were significantly lower, and PaCO2 , HCO3 , and PA-aO2 gradient significantly higher post-induction compared to baseline (p < 0.03). Post-induction and 5-minute physiologic and blood gas values were not significantly different between alfaxalone and propofol. Alfaxalone resulted in significantly longer times to achieve sternal recumbency (p = 0.0003) and standing (p = 0.0004) compared to propofol. Subjective scores for induction, recovery, and ataxia were not significantly different between treatments; however, dogs undergoing alfaxalone anesthesia were more likely to have ≥ 1 adverse event (p = 0.041). There were no serious adverse events in either treatment.

CONCLUSIONS AND CLINICAL RELEVANCE: There were no clinically significant differences in cardiopulmonary effects between propofol and alfaxalone. A single bolus of propofol resulted in shorter recovery times and fewer adverse events than a single bolus of alfaxalone.