Effects of sevoflurane,isoflurane and desflurane on transcranial electrical motor evoked potentials in patients undergoing neurosurgery / 中华麻醉学杂志

ABSTRACT

Objective To compare the effects of sevoflurane,isoflurane and desflurane on transcranial electrical motor evoked potentials(MEPs)in patients undergoing neurosurgery.Methods Sixty ASA Ⅰ or Ⅱ patients aged 18-64 yr undergoing neurosurgery were randomly divided into 3 groups(n = 20 each) sevoflurane group,isoflurane group and desflurane group.BIS value and MEPs were monitored.The end-tidal concentrations of sevoflurane,isoflurane and desflurane were adjusted and maintained at 0.50,0.75,1.00 and 1.30 MAC respectively for at least 15 min during 6 stimuli delivered at 1000 Hz and 300 V lasting for 75 μs.The amplitudes and latency of MEPs and BIS value were recorded before administration(baseline)and the each stable state (T1-4).The failure rate of MEPs was also recorded.Results The amplitude of MEPs and BIS value were significantly decreased at T1.2 and the latency of MEPs was prolonged at T1-4 in desflurane group compared with sevoflurane and isoflurane groups(P＜0.05).There was no significant difference in the amplitudes and latency of MEPs and BIS value between group sevoflurane and isoflurane(P＞0.05).The failure rates of MEPs were 0 at baseline,T1 and T2,0,5% and 20% at T3 ,and 5%,20% and 45% at T4 in sevoflurane,isoflurane and desflurane groups respectively.The failure rate of MEPs was significantly higher in desflurane group than in sevoflurane and isoflurane groups(P＜0.05).Conclusion Desflurane has greater suppressive effect on MEPs than sevoflurane and isoflurane.1.00 MAC of sevoflurane and isoflurane,while 0.75-1.00 MAC of desflurane may be the suitable end-tidal concentration for MEP monitoring.