RESUMO
OBJECTIVE: To study the feasibility of using Narcotrend (NCT) in monitoring the anesthetic depth during endotracheal intubation in sevoflurane anesthesia. METHODS: Thirty ASA I-II patients (aged 20-49 years) undergoing gynecologic surgery under general anesthesia with tracheal intubation were randomized into sevoflurane group (n=15) and sevoflurane plus rocuronium group (n=15). In the former group, anesthesia was induced with sevoflurane at the primary concentration of 8% till the final end expiratory concentration reaching 2 MAC(minimum alveolar concentration) for 3 min, followed then by tracheal intubation and further observation of the indicators for another 3 min. The patients in sevoflurane plus rocuronium group received identical anesthesia procedures except for the administration of intravenous injection of rocuronium (0.6 mg/kg) after the loss of eyelash reflex. The NCT, BIS and hemodynamics were recorded during the process. RESULTS: No significant differences were noted in NCT, bispectral index (BIS), MAP and heart rate before tracheal intubation between the two groups (P>0.05). The NCT and BIS increased significantly after tracheal intubation in sevoflurane group (P<0.05), but remained below 60. No significant changes in NCT and BIS occurred during intubation in sevoflurane plus rocuronium group (P>0.05). The mean arterial pressure (MAP) and heart rate were significantly increased in both groups after tracheal intubation in comparison with those before tracheal intubation (P<0.05), but the increment in sevoflurane group was significantly greater (P<0.05). CONCLUSION: NCT may reflect the changes of the anesthetic depth resulting from the nociceptive stimulus of tracheal intubation in sevoflurane- induced anesthesia. NCT and BIS can not serve such a purpose in combined anesthesia with sevoflurane and rocuronium.