OBJECTIVETo study the feasibility of using Narcotrend (NCT) in monitoring the anesthetic depth during endotracheal intubation in sevoflurane anesthesia.

METHODSThirty 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.

RESULTSNo 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).

CONCLUSIONNCT 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.