Retrospective evaluation of clinical use of cis-atracurium in horses

Abstract

Background To the authors’ knowledge, there are no reports describing the use of cis-atracurium in the horse. Objective To describe the onset time and the duration of the neuromuscular blockade (NMB) of three different doses of cis-atracurium in horses and to determine the appropriate dose needed maintain a NMB. Study design Retrospective study. Methods Horses which received cis-atracurium as part of a balanced anaesthetic protocol at the Equine Teaching Hospital of the University of Liège between March 2014 and June 2017 were included in this study. A train-of-four (TOF) stimulation pattern was used to assess the NMB. The cis-atracurium induction dose, the onset and duration of action (when TOF count was under three twitches) of the first bolus, the number of supplementary boluses of cis-atracurium and the total dose of cis-atracurium administered per horse, the total duration of the NMB and the recovery time were recorded and analysed. Also the use of an antidote and any side effects produced by cis-atracurium were recorded. Results From 37 horses that received cis-atracurium during this period, only 23 had a complete records and were included in the study. Three different doses of cis-atracurium were used to induce NMB: 100 μg/kg ( n = 8) 75 μg/kg ( n = 3) and 50 μg/kg ( n = 12). Cis-atracurium 50 μg/kg failed to induce NMB in 3 horses. The onset of action was not significantly different between the three doses (5 minutes). The duration of the NMB was dose-dependent. The calculated dose of cis-atracurium necessary to maintain a NMB was 2.3 μg/kg/minute based on the sum of the induction dose and the supplementary boluses divided by the duration of the NMB. Main limitations A further prospective study is needed to confirm the results. Conclusions Cis-atracurium can be an alternative to other NMBA in horses.

Monitoring techniques for equine anaesthesia

“…This is because communication between the motor neuron and muscle end plate is blocked by NMBAs binding to motor end‐plate acetylcholine receptors. The motor nerve selected depends on available access, but the superficial peroneal or radial nerve represent sensible choices (Martin‐Flores, 2013; Mosing et al., 2010; Taylor & Clarke, 2007b; Tutunaru et al., 2019). The facial nerve may be a suboptimal choice due to the relative insensitivity of the corresponding muscles to NMBAs (Mosing et al., 2010).…”

“…Ensuring adequate hypnosis and analgesia before and during the use of NMBA use is essential for welfare. The use of nondepolarising agents (such as rocuronium or cis-atacurium) in horses has been described in ophthalmological surgery to achieve a central eye position and to facilitate orthopaedic procedures (Auer & Moens, 2011;Tutunaru et al, 2019). Monitoring the degree of neuromuscular block should always be performed to avoid residual neuromuscular block on recovery and to assist in decision making regarding the use of reversal agents (Bechara et al, 1999).…”

Neuromuscular blockade with atracurium for ophthalmic surgery in horses—Effects on surgical and anesthetic characteristics and recovery quality

“…The use of neuromuscular blocking agents in horses was first reported in the 1950s 1–5 . Nondepolarizing muscle relaxants are associated with reduced side effects; agents used in veterinary medicine include pancuronium, rocuronium, vecuronium and atracurium 2,3,6,7 . Onset and duration of action of these drugs have been shown to be dose‐dependent, and side effects are few 1,2,8,9 .…”