ONSET OF NEUROMUSCULAR BLOCK IS THE SAME IF THE IPSILATERAL OR CONTRALATERAL LIMB TO THE INJECTION SITE IS USED FOR MONITORING

We studied 40 healthy adult patients undergoing elective surgery who w ere premedicated with flunitrazepam. Before induction of anaesthesia, one of the upper limbs was cannulated and an i.v. infusion of 0.9% sal ine commenced. Patients were given fentanyl and thiopentone for induct ion of anaesthesia and then 50% (20 patients) received atracurium 0.5 mg kg(-1) and the other 50% vecuronium 0.1 mg kg(-1). Neuromuscular bl ock (maximum degree of depression of the elicited first twitch and the onset time of depression of twitch height to 50%, 90% and 100% of con trol) and skin temperature (at the thenar eminence) were monitored in both the limb with the i.v. infusion and the non-cannulated upper limb . There was no difference in onset time and degree of neuromuscular bl ock between the two upper limbs. Skin temperature was not significantl y different between the two upper limbs. We conclude that each upper l imb, irrespective of whether an i.v. infusion is in progress, may be u sed for monitoring onset of neuromuscular block.