PURPOSE: A dose-response relationship study for edrophonium to examine the modification of volatile anaesthetics on reversal of vecuronium block. METHODS:One hundred and twenty ASA (I-II) patients were anaesthetized withsevoflurane, isoflurane (1 minimum alveolar anaesthetic concentration [MAC] end-tidal concentration), or fentanyl-diazepam anaesthesia, in combination with 66% nitrous oxide (n = 40 for each group). The evoked electromyogram (EMG) response of the abductor digiti minimi was monitored at 20 sec intervals following train-of-four (TOF) stimulation of the ulnar nerve. The initial neuromuscular block was produced by vecuronium 100 micrograms.kg-1. When the amplitude of the first response (T1) had spontaneously recovered to 10% of the control, edrophonium (0, 125, 400, 700 or 1000 micrograms.kg-1; eight patients each) was randomly administered, and the ratio of the fourth TOF to the first response (TOFR) was monitored at one minute intervals for 10 min. RESULTS:Sevoflurane and isoflurane impaired the edrophonium-assisted TOFR recovery in an edrophonium dose and time dependent manner. The dose-response curves at 10 min exhibited a greater shift to the right in the sevoflurane and isoflurane groups than in the fentanyl-diazepam-nitrous oxide group (P < 0.05). Higher ED50 values (the edrophonium dose required to obtain TOFR value of 50%) in the sevoflurane (> 1000 micrograms.kg-1) and isoflurane groups (851 micrograms.kg-1) were observed than in the fentanyl-diazepam-nitrous oxide group (339 micrograms.kg-1) (P < 0.05). CONCLUSION: One MAC sevoflurane and isoflurane anaesthesia impair edrophonium reversal of vecuronium block to a similar degree.
RCT Entities:
PURPOSE: A dose-response relationship study for edrophonium to examine the modification of volatile anaesthetics on reversal of vecuronium block. METHODS: One hundred and twenty ASA (I-II) patients were anaesthetized with sevoflurane, isoflurane (1 minimum alveolar anaesthetic concentration [MAC] end-tidal concentration), or fentanyl-diazepam anaesthesia, in combination with 66% nitrous oxide (n = 40 for each group). The evoked electromyogram (EMG) response of the abductor digiti minimi was monitored at 20 sec intervals following train-of-four (TOF) stimulation of the ulnar nerve. The initial neuromuscular block was produced by vecuronium 100 micrograms.kg-1. When the amplitude of the first response (T1) had spontaneously recovered to 10% of the control, edrophonium (0, 125, 400, 700 or 1000 micrograms.kg-1; eight patients each) was randomly administered, and the ratio of the fourth TOF to the first response (TOFR) was monitored at one minute intervals for 10 min. RESULTS:Sevoflurane and isoflurane impaired the edrophonium-assisted TOFR recovery in an edrophonium dose and time dependent manner. The dose-response curves at 10 min exhibited a greater shift to the right in the sevoflurane and isoflurane groups than in the fentanyl-diazepam-nitrous oxide group (P < 0.05). Higher ED50 values (the edrophonium dose required to obtain TOFR value of 50%) in the sevoflurane (> 1000 micrograms.kg-1) and isoflurane groups (851 micrograms.kg-1) were observed than in the fentanyl-diazepam-nitrous oxide group (339 micrograms.kg-1) (P < 0.05). CONCLUSION: One MAC sevoflurane and isoflurane anaesthesia impair edrophonium reversal of vecuronium block to a similar degree.
Authors: Hendrikus Jm Lemmens; Mohammad I El-Orbany; James Berry; Jovino Ben Morte; Gavin Martin Journal: BMC Anesthesiol Date: 2010-09-01 Impact factor: 2.217