Comparison of inhaled salbutamol and salmeterol for the treatment of arterial hypoxaemia in anaesthetized horses: a randomized clinical trial
Comparison of inhaled salbutamol and salmeterol for the treatment of arterial hypoxaemia in anaesthetized horses: a randomized clinical trial
Requires membership/payment
This article can be accessed via RCVS Knowledge Library Membership (click here).
In our edition of: Aug 2024
In our categories of: equine
our summary:
Dupont, J. et al. (2024) Comparison of inhaled salbutamol and salmeterol for the treatment of arterial hypoxaemia in anaesthetized horses: a randomized clinical trial. Veterinary Anaesthesia and Analgesia
The aim of this prospective, randomised clinical trial was to compare the efficacy of inhaled salbutamol and salmeterol for treatment of arterial hypoxaemia in anaesthetised horses. The authors hypothesised that both drugs would be equally effective, but that salmeterol would be longer-acting.
Cases were recruited from client-owned horses anaesthetized at an equine hospital in Belgium between September 2020- April 2022. Horses were premedicated with acepromazine (0.1 mg/kg intramuscularly (IM) or 0.05 mg/kg intravenously (IV)) and xylazine (0.6 mg/kg IV); induction of anaesthesia was a combination of ketamine (2.2 mg/kg IV) and midazolam (0.06 mg/kg IV); and isoflurane in oxygen/air mixture was used for maintenance of anaesthesia. A cannula was placed in in the transverse facial artery, the facial artery or the dorsal metatarsal artery for repeated arterial blood sampling and continuous direct arterial pressure measurement.
The final study population of 108 horses included 57 admitted for elective surgery and 51 as emergency cases, 53 had a laparoscopic procedure and 55 another type of surgery. 88 horses were in dorsal recumbency position, 11 in right lateral recumbency and nine horses in left lateral recumbency. Horses were randomly assigned to received either salbutamol (2 µg/kg, n=60) or salmeterol (0.5 µg/kg, n=48).
Results showed the systolic, mean and diastolic arterial pressures were not significantly different between the two treatment groups at 15 and 30 minutes after drug administration. However, arterial partial pressure of oxygen (PaO2) was significantly higher in the salbutamol group at 15 and 30 minutes than in the salmeterol group.
Limitations of the study include the timepoint of 30 minutes after treatment for the final arterial blood gas measurement might have meant that salmeterol may not have reached its full effect by this time as its time-to-peak effect is between 30-60 minutes. The sample population of 108 horses was less than the calculated study sample size of 126.
This study showed that following this protocol inhaled salbutamol was more effective than salmeterol in improving PaO2 in anaesthetised horses with value <100 mmHg (13.3 kPa).
The following may also be of interest:
Bennell, A. (2021) In horses undergoing volatile anaesthesia, does intraoperative alpha-2-agonist infusion improve recovery? Veterinary Evidence, 6 (1). https://doi.org/10.18849/ve.v6i1.341
Hovda, T., Love, L. and Chiavaccini, L. (2022) Risk factors associated with hypoxaemia in horses undergoing general anaesthesia: A retrospective study. Equine Veterinary Journal, 54 (6), pp.1055–1063. https://doi.org/10.1111/evj.13541
Deutsch, J. and Taylor, P.M. (2022) Mortality and morbidity in equine anaesthesia. Equine Veterinary Education, 34 (3), pp. 152-168. https://doi.org/10.1111/eve.13431
Claiming CPD for reading inFOCUS articles
Reading and reflecting on articles can count towards your CPD, and we have a template to help you with the process.
Image copyright attribute: serezniy / 123RF Stock Photo
Leave a Reply
Want to join the discussion?Feel free to contribute!