The Application Of Entropy And BIS In Monitoring The Depth Of During Anesthesia Induction With Inhaled Sevoflurane In Elderly Patients

【Objective】To observe the changes of response entropy(RE),state entropy(SE), bispectral index(BIS),sevoflurane MAC and hemodynamic during anesthesia induction with sevoflurane in elderly patients,and assess the appliction of entropy and BIS in monitoring the depth of anesthesia.【Methods】Thirty-four ASAⅠ-Ⅱelderly patients undergoing selective surgery were included in this study.Anaesthesia was induced by inhalation of 6%sevoflurane with a fresh gas flow of 6L/min(100%oxygen) via a face mask.After loss of consciousness,fentanyl 2μg/kg,atracurium 0.6 mg/kg was administered to the patient,and anesthesia induction continue with inhalation of 3%sevoflurane with a fresh gas flow of 3L/min,three minutes later the trachea was inserted.RE,SE,BIS, MAP and HR were recorded at the time points of before induction(T0),loss of consciousness(Tu),befor intubation(Tb),immediate intubation(Ti),at 20s(T1), 40s(T2),1min(T3),1.5min(T4),2min(T5),3min(T6) after intubation,and sevoflurane MAC was recorded at Tu,Tb,T3,T5.【Results】Sevoflurane MAC was 2.30±0.5 at Tu,and RE(87.6±15.5), SE(79.9±13.5) were represented to be awake,BIS(73.6±12.3) indicated sedation.MAP (84.7±7.6 mmHg),HR(72.2±5.0bpm) were significantly lower than those at T0 (p＜0.05);sevoflurane MAC was 1.35±0.5 at Tb,and RE(35.8±8.2),SE(35.4±8.1), BIS(40.0±6.8) all indicate deep anesthesia.MAP(78.2±11.1 mmHg),HR(66.9±7.3bpm) at Ti were higher than those at Tb(p＜0.05),but RE(33.7±7.3),SE(36.3±7.2),BIS (40.0±6.8) made no different to those at Tb(p＞0.05),MAP(75.8±7.1 mmHg):HR (68.5±6.5bpm) at T6 recovered to be the level at Tb,while RE(54.8±7.7),SE (47.8±6.0),BIS(54.4±8.4) were not.The changes of RE,SE,BIS was later than those of MAP,HR.The difference between RE and SE after intubation is higher than that before intubation.【Conclusions】In the initial stage of anesthesia induction with sevoflurane in elderly patients,RE,SE,BIS can not reflect anesthesia depth instantly,and sevoflurane MAC is not consistent with anesthesia depth.Sufficient anesthesia depth can not inhibite cardiovascular side response to intubation.RE,SE,BIS are insensitivity to predict patient movements after noxious stimulation,and can not used to monitoring the response proded by noxious stimulation.SE increased more than BIS after noxious stimulation,entropy is insensitivity to predict the process from unconsciousness to consciousness,RE,;The difference between RE and SE can used to indicates inadequate analgesia.