Objective The aim of this study was to investigate if target-controlled-infusion of remifentanil as sole agent affect bispectal index(BIS) and auditory evoked potential index (AEPI).Methods Twenty two ASAⅠ-Ⅱpatients...Objective The aim of this study was to investigate if target-controlled-infusion of remifentanil as sole agent affect bispectal index(BIS) and auditory evoked potential index (AEPI).Methods Twenty two ASAⅠ-Ⅱpatients scheduled for elective surgery were enrolled in this study.A effect-site target-controlled infusion of remifentanil was started to increase concentration gradually , the initial remifentanil concentration was set at 2.0 ng·mL -1 and was increased by 1.0 ng·mL -1 until 8.0 ng·mL -1.At baseline and at each successive target concentration of remifentanil ,the BIS,AEPI ,observer’s assessment of alertness/sedation (OAA/S) ,hemodynamic variables and respiratory rate were recorded.Results Increasing predicted remifentanil effect-site concentration(CeREMI) decreased BIS value,compared with 0 ng·mL -1,the mean values of BIS were significantly reduced from 4.0 ng·mL -1(P<0.05).No significant difference in AEPI values were found.There was great variation existing in reaction to remifentanil in patients.BIS value decreased obviously in 9 patients(≤70)but in another 10 patients remained unchanged(≥90).In 9 remifentanil-sensitive patients,the spearman correlation coefficient of BIS mean value between CeREMI was -0.715 and between OAA/S was 0.705.However,in another10 remifentanil-insensitive patients,we had not found any correlation in BIS mean value between CeREMI or OAA/S. Conclusion We conclude that at the concentration used in clinical practice,great variation exists in patients’ reaction to remifentanil.Whether remifentanil affects BIS or not depend on if it produce sedative effect in patients.We have to consider the individual difference of BIS in remifentanil application.展开更多
Background Neurophysiologic monitoring during surgery is to prevent permanent neurological injury resulting from surgical manipulation. To improve the accuracy and sensitivity of intraoperative neuromonitoring, combin...Background Neurophysiologic monitoring during surgery is to prevent permanent neurological injury resulting from surgical manipulation. To improve the accuracy and sensitivity of intraoperative neuromonitoring, combined monitoring of transcranial electrical stimulation motor evoked potentials （TES-MEPs）, somatosensory evoked potentials （SSEPs） and brainstem auditory evoked potentials （BAEPs） was attempted in microsurgery for lesions adjacent to the brainstem and intracranial aneurysms. Methods Monitoring of combined TES-MEPs with SSEPs was attempted in 68 consecutive patients with lesions adjacent to the brainstem as well as intracranial aneurysms. Among them, 31 patients （31 operations, 28 of posterior cranial fossa tumors, 3 of posterior circulation aneurysms） were also subjected to monitoring of BAEPs. The correlation of monitoring results and clinical outcome was studied prospectively. Results Combined monitoring of evoked potentials （EPs） was done in 64 （94.1%） of the 68 patients. MEPs monitoring was impossible for 4 patients （5.9%）. No complication was observed during the combined monitoring in all the patients. In 45 （66.2%） of the 68 patients, EPs were stable, and they were neurologically intact. Motor dysfunction was detected by MEPs in 8 patients, SSEPs in 5, and BAEPs in 4, respectively. Conclusions A close relationship exists between postoperative motor function and the results of TES-MEPs monitoring TES-MEPs are superior to SSEPs and BAEPs in detecting motor dysfunction, but combined EPs serve as a safe, effective and invasive method for intraoperative monitoring of the function of the motor nervous system. Monitoring of combined EPs during microsurgery for lesions adjacent to the brainstem and intracranial aneurysms may detect potentially hazardous maneuvers and improve the safety of subsequent procedures.展开更多
文摘Objective The aim of this study was to investigate if target-controlled-infusion of remifentanil as sole agent affect bispectal index(BIS) and auditory evoked potential index (AEPI).Methods Twenty two ASAⅠ-Ⅱpatients scheduled for elective surgery were enrolled in this study.A effect-site target-controlled infusion of remifentanil was started to increase concentration gradually , the initial remifentanil concentration was set at 2.0 ng·mL -1 and was increased by 1.0 ng·mL -1 until 8.0 ng·mL -1.At baseline and at each successive target concentration of remifentanil ,the BIS,AEPI ,observer’s assessment of alertness/sedation (OAA/S) ,hemodynamic variables and respiratory rate were recorded.Results Increasing predicted remifentanil effect-site concentration(CeREMI) decreased BIS value,compared with 0 ng·mL -1,the mean values of BIS were significantly reduced from 4.0 ng·mL -1(P<0.05).No significant difference in AEPI values were found.There was great variation existing in reaction to remifentanil in patients.BIS value decreased obviously in 9 patients(≤70)but in another 10 patients remained unchanged(≥90).In 9 remifentanil-sensitive patients,the spearman correlation coefficient of BIS mean value between CeREMI was -0.715 and between OAA/S was 0.705.However,in another10 remifentanil-insensitive patients,we had not found any correlation in BIS mean value between CeREMI or OAA/S. Conclusion We conclude that at the concentration used in clinical practice,great variation exists in patients’ reaction to remifentanil.Whether remifentanil affects BIS or not depend on if it produce sedative effect in patients.We have to consider the individual difference of BIS in remifentanil application.
文摘Background Neurophysiologic monitoring during surgery is to prevent permanent neurological injury resulting from surgical manipulation. To improve the accuracy and sensitivity of intraoperative neuromonitoring, combined monitoring of transcranial electrical stimulation motor evoked potentials （TES-MEPs）, somatosensory evoked potentials （SSEPs） and brainstem auditory evoked potentials （BAEPs） was attempted in microsurgery for lesions adjacent to the brainstem and intracranial aneurysms. Methods Monitoring of combined TES-MEPs with SSEPs was attempted in 68 consecutive patients with lesions adjacent to the brainstem as well as intracranial aneurysms. Among them, 31 patients （31 operations, 28 of posterior cranial fossa tumors, 3 of posterior circulation aneurysms） were also subjected to monitoring of BAEPs. The correlation of monitoring results and clinical outcome was studied prospectively. Results Combined monitoring of evoked potentials （EPs） was done in 64 （94.1%） of the 68 patients. MEPs monitoring was impossible for 4 patients （5.9%）. No complication was observed during the combined monitoring in all the patients. In 45 （66.2%） of the 68 patients, EPs were stable, and they were neurologically intact. Motor dysfunction was detected by MEPs in 8 patients, SSEPs in 5, and BAEPs in 4, respectively. Conclusions A close relationship exists between postoperative motor function and the results of TES-MEPs monitoring TES-MEPs are superior to SSEPs and BAEPs in detecting motor dysfunction, but combined EPs serve as a safe, effective and invasive method for intraoperative monitoring of the function of the motor nervous system. Monitoring of combined EPs during microsurgery for lesions adjacent to the brainstem and intracranial aneurysms may detect potentially hazardous maneuvers and improve the safety of subsequent procedures.
