Anaesthetic and cardiorespiratory effects of propofol at 10% for induction and 1% for maintenance of anaesthesia in horses.
Authors: Muir W W, Lerche P, Erichson D
Journal: Equine veterinary journal
Summary
# Editorial Summary: Propofol Anaesthesia in Horses Muir, Lerche and Erichson investigated the safety and efficacy of concentrated propofol solutions (10% induction, 1% maintenance) in horses, as previous research had established clinical usefulness but left questions about higher concentrations unanswered. Three randomised crossover trials compared induction doses of 2–8 mg/kg of 10% propofol, with and without xylazine premedication, and assessed a 60-minute maintenance protocol using 1% propofol infusion at 0.2–0.4 mg/kg/min. Without sedation, propofol induction proved unpredictable and of poor quality, whilst adequate xylazine premedication (0.5 mg/kg) allowed reliable anaesthesia at 3–5 mg/kg with acceptable recovery characteristics, though a significant decrease in arterial oxygen tension (PaO₂) occurred at these doses. Clinicians can confidently use concentrated propofol formulations for induction and maintenance in horses, but must combine this with xylazine sedation and supplemental oxygen to mitigate hypoventilation and hypoxaemia, particularly in mature animals where respiratory depression represents a meaningful complication.
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Practical Takeaways
- •Concentrated 10% propofol can be used for induction in horses but requires xylazine premedication to ensure adequate anaesthesia quality and safety
- •Always provide supplemental oxygen when using propofol in horses, as significant oxygen desaturation occurs even with appropriate dosing
- •Use 3-5 mg/kg bwt of 10% propofol for induction and 0.2-0.4 mg/kg bwt/min of 1% propofol for maintenance in xylazine-premedicated horses to achieve acceptable anaesthetic quality
Key Findings
- •10% propofol solution can induce anaesthesia in horses when preceded by xylazine premedication, with acceptable quality of induction and recovery
- •Doses of 3-5 mg/kg bwt of 10% propofol produced anaesthesia lasting 10-25 minutes in xylazine-sedated horses
- •Significant decrease in PaO2 occurred in horses administered 3-5 mg/kg bwt propofol, indicating hypoventilation and hypoxaemia risk
- •Maintenance anaesthesia with 1% propofol infusion (0.2-0.4 mg/kg bwt/min) for 60 minutes produced acceptable results with minimal cardiovascular changes when horses received xylazine premedication