Relationship between evoked potential and recovery after isoflurane anesthesia

    ZHANG Hanª²Ping, CHAI Wei, DU Hongª²Yin, ZHAO Hui, YANG Yongª²Hui, SUN Xuª²De, YU Daiª²Hua

    1Department of Anesthesiology, Jiangsu Provincial Corps Hospital, Chinese People¬ðs Armed Police Forces,Yangzhou 225003, China, 2Department of Anesthesiology, Tangdu Hospital, Fourth Military Medical University, Xi¬ðan 710038, China

    ¡¾Abstract¡¿ AIM: To investigate the relationship between evoked potential (EP) and recovery time after isoflurane anesthesia for some credible parameters in recovery monitoring after isoflurane anesthesia. METHODS: Twenty patients undergoing abdominal surgery under elective general anesthesia were maintained with isoflurane after induction. SEP, AEP and the endª²expiratory concentration of isoflurane were recorded before the discontinuation of isoflurane at different concentrations for 15 min. Commander reflect time, extubation time and the time to reach modified Aldrete score ¡Ý 9 were observed from the end of anesthesia. RESULTS: ¢Ù The amplitude of EP had a big variance and was not correlated with recovery time. ¢Ú The latency of all waves in AEP was correlated with recovery time. The change of Nb latency was correlated with all recoveryª²related indexes. ¢Û There was no significant variance in the N20 latency of SEP but there was a big variance in the latency of N35, which was not correlated with recovery time. The latency of P25 was correlated with recovery time. ¢Ü Nb and P25 had a better correlation with recovery time than endª²expiratory concentration of isoflurane. ¢Ý The correlation coefficients of all indexes with recovery time were Nb latency > P25 latency > the endª²expiratory concentration of inhaled anesthetics. CONCLUSION: ¢Ù The Nb latency of AEP and the P25 latency of SEP are significantly correlated with the command reflect time, extubation time and the time to reach modified Aldrete score ¡Ý 9. The latency of Nb and P25 are credible indexes in the determination of recovery time after inhaled anesthesia. ......