O Moerer1, J Bittner, J Hinz, M Sydow. 1. Zentrum Anaesthesiologie, Rettungs- und Intensivmedizin der Georg-August-Universität Göttingen. omoerer@gwdg.de
Abstract
OBJECTIVE: Onset time and recovery from non depolarising neuromuscular blockade depends on the tested muscle and is influenced by the age of the patient. This study compares the neuromuscular blocking effect of rocuronium on the diaphragm, adductor pollicis and orbicularis oculi muscle in young and elderly patients. METHODS: After institutional ethics committee approval and written informed consent, 20 adult patients (ASA I - II), age 18 - 59 and > 65, have been included. Neuromuscular response was measured by accelerography for the adductor pollicis and orbicularis oculi muscle. Monitoring of the diaphragm consisted of measurement of the airway pressure against an occluded tracheal tube during magnetic phrenic nerve stimulation. Onset time and recovery were measured after injection of 0.6 mg/kg Rocuronium. RESULTS: The adductor pollicis had the fastest onset time ( young 2.3 min, old 2.2 min), followed by diaphragm ( young 3.6 min, old 3.4 min) and orbicularis oculi muscle ( young 3.7 min, old 4.8 min). There was a complete blockade of the diaphragm in 50 % of all patients (Adductor pollicis 100 %, orbicularis oculi 40 %). Neuromuscular recovery, recovery index and TOF 0.8 differed significantly between young and elderly patients. Onset of recovery was earlier at the diaphragm ( young 15.9 min, old 22.0 min) compared to the peripheral muscles (adductor pollicis young 25.6 min, old 37.9 min, orbicularis oculi young 23.8 min, old 27.5 min). CONCLUSION: 2 fould ED95 of rocuronium often results in an incomplete neuromuscular blockade of the diaphragm. Therefore monitoring of the peripheral muscles in patients given a single dose of rocuronium often overestimates the degree of diaphragmatic relaxation, but is a save predictor of recovery. Especially in elderly patients were prolonged neuromuscular blockade should be expected, a neuromuscular monitoring is recommended.
OBJECTIVE: Onset time and recovery from non depolarising neuromuscular blockade depends on the tested muscle and is influenced by the age of the patient. This study compares the neuromuscular blocking effect of rocuronium on the diaphragm, adductor pollicis and orbicularis oculi muscle in young and elderly patients. METHODS: After institutional ethics committee approval and written informed consent, 20 adult patients (ASA I - II), age 18 - 59 and > 65, have been included. Neuromuscular response was measured by accelerography for the adductor pollicis and orbicularis oculi muscle. Monitoring of the diaphragm consisted of measurement of the airway pressure against an occluded tracheal tube during magnetic phrenic nerve stimulation. Onset time and recovery were measured after injection of 0.6 mg/kg Rocuronium. RESULTS: The adductor pollicis had the fastest onset time ( young 2.3 min, old 2.2 min), followed by diaphragm ( young 3.6 min, old 3.4 min) and orbicularis oculi muscle ( young 3.7 min, old 4.8 min). There was a complete blockade of the diaphragm in 50 % of all patients (Adductor pollicis 100 %, orbicularis oculi 40 %). Neuromuscular recovery, recovery index and TOF 0.8 differed significantly between young and elderly patients. Onset of recovery was earlier at the diaphragm ( young 15.9 min, old 22.0 min) compared to the peripheral muscles (adductor pollicis young 25.6 min, old 37.9 min, orbicularis oculi young 23.8 min, old 27.5 min). CONCLUSION: 2 fould ED95 of rocuronium often results in an incomplete neuromuscular blockade of the diaphragm. Therefore monitoring of the peripheral muscles in patients given a single dose of rocuronium often overestimates the degree of diaphragmatic relaxation, but is a save predictor of recovery. Especially in elderly patients were prolonged neuromuscular blockade should be expected, a neuromuscular monitoring is recommended.