The tof-guard neuromuscular transmission monitor and its use in horses

Abstract

It has been emphasized in the human medical literature, that when using a neuromuscular blocking agent, it is of vital importance the monitoring of the neuromuscular block and that these agents should never be used without it. The purpose of this study was to evaluate the use of the neuromuscular transmission monitor TOF-Guard in horses. Twelve horses were randomly assigned whether to receive pancuronium or atracurium as the neuromuscular blocking agent. All horses were pre-medicated with romifidine, anaesthesia induced with diazepam and ketamine and maintenance with halothane. Abolition of spontaneous ventilation was accomplished by the administration of atracurium or pancuronium. The time from injection of the muscle relaxant agent to the onset of maximum block (T1=0), recovery of T1 to 25% and the recovery of TOF ratio to 0.7 were recorded, as was the time for recovery of T1 from 25 to 75%. It was concluded that it is very important the neuromuscular transmission monitoring during the use of a nondepolarizing neuromuscular blocking agent, since it provides a safer anaesthetic and surgical procedure with the use of adequate dosages and due to the impossibility of a superficialization of the neuromuscular blockade during a surgical procedure. The TOF-Guard showed to be a good option for neuromuscular monitoring in horses.