The use of bispectral index monitors in paediatric intensive care

The bispectral index (BIS) is a processed neurophysiological electroencephalographic parameter that may be used to evaluate the depth of sedation in critically ill children. Triltsch and colleagues attempted to correlate BIS scores with a commonly used clinical sedation scoring system. They were able to demonstrate good correlation during deep sedation and in cases where the electrical impedance of the BIS electrodes was lowest. Studies have shown only moderate degrees of correlation between BIS scores and clinical sedation scoring systems. There is currently insufficient evidence to recommend routine monitoring of BIS scores in critically ill children.     

Comparison of the bispectral index monitor with the Comfort score in assessing level of sedation of critically ill children

Objective To compare the value of bispectral index as a monitor of sedation in critically ill children with a validated sedation scoring system.Design Prospective convenience sample.Setting Paediatric intensive care unit in a tertiary paediatric centre.Patients and participants Forty-three critically ill children receiving sedation and mechanical ventilation.Measurements and results Simultaneous recording of bispectral index (BIS) and assessment of depth of sedation using the Comfort score were performed at regular intervals. To determine if BIS could detect episodes of arousal, times of endotracheal suctioning and the corresponding BIS score were recorded. There was an overall moderate correlation between BIS scores and Comfort scores (r=0.50, r²=0.25, p<0.0001). Children who had a neurological reason for their current admission (n=25) showed a weaker correlation (r=0.26, r²=0.06, p<0.007) than those (n=15) with normal neurology (r=0.51, r²=0.26, p<0.0001). There were no significant differences in the rise in BIS following endotracheal suctioning among any of the predefined depths of sedation. There was a correlation of r=0.84 (r²=0.71) (SE of slope 0.49, CI₉₅ 1.79–3.88) for mean BIS values for each individual Comfort score from 8–23. Using Spearman's rank correlation of Comfort versus mean BIS, the correlation coefficient was r=0.92.Conclusions Bispectral index scores correlate with Comfort scores to a moderate degree. BIS is able to discriminate between light and deep levels of sedation, but not between deep and very deep levels of sedation. The BIS monitor may provide a useful method for assessing sedation in critically ill children, especially those receiving neuromuscular blockers.     

Bispectral Index monitoring correlates with sedation scales in brain-injured patients

OBJECTIVE: Monitoring critically ill, brain-injured patients with a decreased level of consciousness is challenging. Our goal is to determine in this population the correlation between the Bispectral Index (BIS) and three commonly used sedation agitation scales: the Richmond Agitation-Sedation Scale (RASS), the Sedation-Agitation Scale (SAS) and the Glasgow Coma Scale (GCS) scores. DESIGN: Prospective, single-blinded observational study. SETTING: Eight-bed neurology-neurosurgery intensive care unit at the Cleveland Clinic Foundation. PATIENTS: Thirty critically ill patients admitted to the neurointensive care unit with primary brain injury and a decreased level of consciousness. MEASUREMENTS AND MAIN RESULTS: Patients were prospectively evaluated for level of consciousness using the RASS, SAS, and GCS every hour and simultaneously were monitored continuously with a BIS monitor for 6 hrs. A Spearman's correlation coefficient was used to correlate the BIS scores with clinical scales. In 15 patients monitored with the newer BIS XP version, the BIS values correlated significantly with the RASS (R2 = .810; p < .0001), SAS (R2 = .725; p < .0001), and GCS (R2 = .655; p < .0001). In 15 patients monitored with the older BIS 2.1.1 software, the correlation was as follows: for RASS, R2 = .30 (p < .008), for SAS: R2 = .376 (p < .001), and for GCS: R2 = .274 (p < .015). This correlation was maintained in patients who received sedative medications. CONCLUSIONS: A statistically significant correlation existed between BIS values and the RASS, SAS, and GCS scores in critically ill brain-injured patients, with and without sedation. The newer BIS XP software package may be a useful adjunctive tool in objective assessment of level of consciousness in brain-injured patients.     

Frequency and clinical impact of preserved bispectral index activity during deep sedation in mechanically ventilated ICU patients

Objective  

Despite an overall correlation between the bispectral index of the EEG (BIS) and clinical sedation assessment, unexpectedly high BIS values can be observed at deep sedation levels. We assessed the frequency, interindividual variability and clinical impact of high BIS values during clinically deep sedation.     

脑电双频指数监测对机械通气患者镇静深度评估的研究

目的 观察脑电双频指数(BIS)监测与主观评分的相关性,研究其对机械通气患者镇静深度评估的可行性.方法 将重症监护病房(ICU)需要机械通气的83例患者随机分为两组,设定镇静目标为镇静一躁动评分(SAS)3～4分,分别用BIS(研究组,42例)和SAS(对照组,41例)监测患者的镇静深度,记录两组患者镇静前及镇静后每隔16 h的呼吸、循环指标和BIS、SAS、Ramsay 3种镇静评分,比较组间差异,分析各种评分的相关性.结果 83例患者均达镇静目标,两组间呼吸、循环指标比较差异均无统计学意义(P均>0.05).所有患者镇静后呼吸频率、吸入氧浓度较镇静前显著下降,脉搏血氧饱和度显著升高,差异均有统计学意义(P均<0.05);BIS值与主观评分间相关性良好,其中BIS与SAS评分呈显著正相关(r=0.626,P<0.05),与Ramsay评分呈显著负相关(r=-0.650,P<0.05),SAS与Ramsay评分呈显著负相关(r=0.908,P<0.05).结论 用BIS监测评估机械通气患者镇静深度简单方便、同步有效,是评价ICU机械通气患者镇静深度的良好客观指标.     

The effect of neuromuscular blockade on oxygen consumption in sedated and mechanically ventilated pediatric patients after cardiac surgery

Objective  To measure the effect of intense neuromuscular blockade (NMB) on oxygen consumption (VO₂) in deeply sedated and mechanically ventilated children on the first day after complex congenital cardiac surgery. Design  Prospective clinical interventional study. Setting  Pediatric intensive care unit of an university medical centre. Measurements and results  Nine mechanically ventilated and sedated children (weight 2.8–8.7 kg) were included. All children were treated with vasoactive drugs. The level of sedation was quantified using the comfort score, Ramsay score and bispectral index (BIS). The intensity of NMB was quantified using acceleromyography and VO₂ was measured using indirect calorimetry. Analgo-sedation using various intravenous agents was targeted at a deep level (comfort score < 18, BIS < 60 and Ramsay score > 4). NMB was achieved by intravenous administration of rocuronium. All measurements were conducted before, during and after recovery from a period of intense NMB. Baseline values were VO₂ 6.1 ml/(kg min) (SD 1.3), comfort score 13 (SD 0.7), BIS 42.5 (SD 14.2), mean blood pressure 54.0 mmHg (SD 10.5), mean heart rate 129.9 bpm (SD 28.9) and mean core temperature 36.7°C (SD 0.5). There were no significant differences in VO₂ or other parameters between baseline, during NMB and the recovery phase. Conclusion  Neuromuscular blocking agents do not reduce oxygen consumption in deeply sedated and mechanically ventilated children after congenital cardiac surgery.     

Grado de sedación del paciente crítico pediátrico y variables sociodemográficas y clínicas correlacionadas. Estudio multicéntrico COSAIP

AimsTo determine the grade of sedation in the critically ill paediatric patient using Biespectral Index Sensor (BIS) and to analyse its relationship with sociodemographic and clinical patient variables.MethodsObservational, analytical, cross-sectional and multicentre study performed from May 2018 to January 2020 in 5 Spanish paediatric critical care units. Sex, age, reason for admission, presence of a chronic pathology, type and number of drugs and length of stay were the sociodemographic and clinical variables registered. Furthermore, the grade of sedation was assessed using BIS, 11 per shift over 24 hours.ResultsA total of 261 paediatric patients, 53.64% of whom were male, with a median age of 1.61 years (0.35-6.55), were included in the study. Of the patients, 70.11% (n = 183) were under analgosedation and monitored using the BIS sensor. A median of BIS values of 51.24 ± 14.96 during the morning and 50.75 ± 15.55 during the night were observed. When comparing BIS values and sociodemographic and clinical paediatric variables no statistical significance was detected.ConclusionsDespite the limitations of the BIS, investigations and the present study show that BIS could be a useful instrument to assess grade of sedation in critically ill paediatric patients. However, further investigations which determine the sociodemographic and clinical variables involved in the grade of paediatric analgosedation, as well as studies that contrast the efficacy of clinical scales like the COMFORT Behaviour Scale-Spanish version, are required.     

Assessing the predictive value of the bispectral index vs patient state index on clinical assessment of sedation in postoperative cardiac surgery patients

Purpose

To compare the depth of sedation determined by Ramsay sedation scale (RSS) with electroencephalogram-based bispectral index (BIS) and patient state index (PSI).

Materials and Methods

Fifty mechanically ventilated cardiac surgical patients undergoing propofol and morphine sedation were assessed hourly for up to 6 hours or until tracheal extubation using the BIS, PSI, and RSS. Correlation between RSS, BIS, and PSI was determined, as well as the interrater reliability of RSS, BIS, and PSI. κ statistics was used to further evaluate the agreement between BIS and PSI.

Results

There was positive correlation between BIS and PSI values (ρ = 0.731, P < .001). The average weighted κ coefficient was .40 between the BIS and PSI, 0.28 between the RSS and BIS, and 0.16 between the RSS and PSI. Intraclass correlation was consistently higher between the BIS and PSI at all time intervals during the study. Logistic regression modeling over study duration showed that the BIS was consistently better at predicting oversedation (area under the curve, 0.92) than the PSI (area under the curve, 0.78). A comparison of BIS and PSI receiver operating characteristic curves showed that the BIS monitor was a better predictor of oversedation compared with the PSI (P = .02).

Conclusions

There is significant positive correlation between the BIS and PSI but poor correlation and poor test agreement between the RSS and BIS as well as RSS and PSI. The BIS is a better predictor of oversedation compared with the PSI. There was no significant difference between the BIS and PSI with respect to the prediction of undersedation.     

Use of bispectral electroencephalogram monitoring to assess neurologic status in unsedated, critically ill patients

OBJECTIVE: To test whether spectral indices derived from the electroencephalogram (EEG), and especially the bispectral index (BIS), can be used as measures of neurologic status in unsedated, critically ill patients. DESIGN: Prospective, observational study. SETTING: Medical intensive care unit (ICU) of a university-affiliated teaching hospital. PATIENTS: Thirty-one awake, unsedated critically ill adults were assessed in 108 separate sessions. MEASUREMENTS AND MAIN RESULTS: In each session, severity of illness was assessed by the Acute Physiology and Chronic Health Evaluation (APACHE III). The APACHE III Acute Physiology Score was used to quantify the degree of physiologic derangement. Neurologic function was assessed using the APACHE III Neurologic Score, the Glasgow Coma Scale, the Reaction Level Scale, and the Modified Ramsay Sedation Scale. All indices were plotted against various spectral parameters of the EEG, including BIS, an empirical index of EEG activity that is scaled from 0 to 100. BIS was significantly (p <.05) correlated with neurologic score regardless of scoring system used and was more strongly correlated than any other EEG spectral parameter. Better neurologic function was associated with higher values of BIS. In multivariate analysis, the combination of BIS and relative power in the theta band of the EEG accounted for 38% of the variability in the Glasgow Coma Scale. CONCLUSIONS: BIS provides a reliable index of neurologic status in awake, unsedated, critically ill patients. Further research is needed to determine whether the effects of neurologic status and pharmacologic sedation upon EEG are additive, whether BIS can be used to assess pharmacologic sedation in the critically ill patient population, and whether such objective measures of neurologic status have prognostic value.     

Effects of neuromuscular block on systemic and cerebral hemodynamics and bispectral index during moderate or deep sedation in critically ill patients

Objective To investigate whether neuromuscular block can affect bispectral index (BIS) or cerebral hemodynamics under moderate or deep sedation produced by propofol. Design and setting Prospective, controlled study in a university hospital affiliated intensive care unit. Patients Seventeen surgical patients undergoing elective esophagectomy. Interventions After stabilization with either light or deep sedation we investigated whether the BIS, electromyographic activity (EMG), or cerebral and systemic hemodynamic parameters were affected by administration of muscle relaxant. Measurements and main results Neuromuscular block reduced the BIS during moderate sedation but not during deep sedation although the EMG at both levels of sedation was significantly reduced. No positive effects of neuromuscular block on cerebral hemodynamics were obtained with monitoring of regional cerebral oxygen saturation and middle cerebral artery blood velocity; however, significant effects on systemic hemodynamic parameters were observed only at moderate propofol sedation. The values of BIS and systemic hemodynamic variables with moderate sedation were also very similar to those with deep sedation and neuromuscular block although these values differed without neuromuscular block. Conclusions Neuromuscular block altered the BIS score in moderately sedated patients but not in deeply sedated patients although cerebral hemodynamics was not affected by neuromuscular block during either moderate or deep sedation. Muscular relaxant also enhanced cardiovascular stability with moderate sedation. These results suggest that level of consciousness may be decreased by neuromuscular block during moderate sedation but not affected during deep sedation.     

Acute microflow changes after stop and restart of intra-aortic balloon pump in cardiogenic shock

Background  The intra-aortic balloon counter pulsation (IABP) is the most frequently used method of mechanical cardiac support in cardiogenic shock (CS). Microcirculatory impairment correlates with outcome in critically ill patients. We therefore investigated the acute influence of IABP therapy on sublingual microflow in patients with CS. Methods  Sidestream darkfield intravitalmicroscopy was used in 13 patients with severe CS. The sublingual microvascular bed (10–100 μm) was examined according to current guidelines. We measured microflow in means of microvascular flow index at baseline and after intentional stop of IABP support. A computerized model was used for blinded off-line analysis. Results  Microflow in vessels 10–50 μm in diameter was improved during IABP support (P < 0.001). Norepinephrine had a negative effect on the response to IABP related microflow improvement. Cardiac Perfusion Index (product of Cardiac Power index and microflow) correlated best with blood lactate levels. Conclusions  It was the aim of this study to evaluate the acute influence of IABP therapy on microflow in vivo. In this setting we found that IABP therapy improves sublingual microflow. Future studies should investigate Cardiac Perfusion Index under such conditions with respect to clinical decision making. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

脑电双频指数与镇静-躁动评分评价机械通气患者镇静程度可靠性的比较研究

目的探讨脑电双频指数(BIS)评价重症监护室(ICU)危重患者镇静程度的可靠性。方法选择18～65岁、无意识障碍、需持续机械通气(>72h)患者15例。患者入ICU3d7:00停用所有镇痛及镇静剂,待患者完全清醒后静脉泵入异丙酚至BIS目标值为45～60,维持10min后,每间隔10min减少异丙酚泵入量10μg·kg-1·min-1至停止药物泵入。于达到镇静目标以及每次减药后测定BIS值以及镇静躁动评分(SAS)分级。结果BIS值与SAS分级具有良好的相关性(r=0.6494,P<0.01)。但SAS分级在2～4级时,BIS值分布离散度高,相关系数下降(r=0.4566,P<0.01)。随着异丙酚泵入量的逐渐减少,BIS值逐步升高,两者呈现显著的线性负相关(r=0.8076,P<0.01);SAS分级亦显著上升,两者呈现等级负相关(r=0.6551,P<0.01)。结论SAS分级与BIS值在评价ICU机械通气患者镇静程度时存在良好相关性。但在SAS2～4级镇静状态时,BIS能更准确、客观地反映患者镇静程度。     

The use of propofol for medium and long-term sedation in critically ill adult patients: a meta-analysis

Objective  To investigate the effects of using propofol for medium and long-term sedation on mortality and length of intensive care unit (ICU) stay of critically ill adult patients. Design  Randomised controlled studies comparing propofol with an alternative sedative agent in critically ill adult patients were included without language restriction from the Cochrane Controlled Trial Register (2007 issue 3), EMBASE, and MEDLINE databases (1966 to 1 December 2007). Two reviewers reviewed the quality of the studies and performed data extraction independently. Measurements and results  Sixteen randomised controlled studies with a total of 1,386 critically ill adult patients were considered. Nine of the pooled studies (56%) limited the doses of propofol infusion to <6 mg/kg h⁻¹. Mortality was not significantly different between patients sedated with propofol, or an alternative sedative agent (odds ratio [OR] 1.05, 95% confidence interval [CI] 0.80–1.38, P = 0.74; I ²  = 0%). Using propofol for medium and long-term sedation was associated with a significant reduction in length of ICU stay (overall weighted-mean-difference [WMD] in days −0.99, 95%CI −1.51 to −0.47, P = 0.0002; I ² = 82.26%) when compared to an alternative sedative agent; however, this benefit became insignificant (overall WMD in days −0.98, 95%CI −2.86 to 0.89, P = 0.30; I ² = 78.8%) when the comparison was limited to between propofol and midazolam. Conclusions  Using propofol for prolonged sedation in critically ill patients appears to be safe and may reduce duration of mechanical ventilation. It reduces the length of ICU stay when compared to long acting benzodiazepines, but not when compared to midazolam.     

Serum free cortisol index,free cortisol,and total cortisol in critically ill children

Background  In critical illness, serum total cortisol (TC) may not adequately reflect adrenal function because of reduced cortisol-binding globulin (CBG). Aim  To evaluate adrenal function of critically ill children, using free cortisol index (FCI), calculated free cortisol (cFC), and TC levels. Methods  Thirty-two critically ill and 36 healthy children were included. All children underwent the 1 μg cosyntropin test. TC and CBG levels were measured. Basal and peak TC, FCI, and cFC were determined. Results  Basal and peak TC, FCI, and cFC of critically ill children were significantly higher than those of the controls. Compared with TC, both basal and peak FCI and cFC of the patients were higher than those of controls to a greater degree. Use of FCI or cFC to diagnose adrenal insufficiency (AI) reduced the frequency of diagnosis of AI by 50%. Conclusion  FCI and cFC better reflect the dynamic changes of adrenal function of critically ill children.     

Impact of bispectral index monitoring on sedation and outcomes in critically ill adults: a case series

In situations in which clinical assessment of sedation level is compromised, such as deep sedation/analgesia with and without neuromuscular blockade (NMB), electroencephalogram-based monitoring may potentially assist in achieving balance between inadequate and excessive levels of sedation. To validate the bispectral index (BIS) for use in clinical practice, correlation and possible differences in outcome using clinical assessment versus clinical assessment augmented by electroencephalogram-based monitoring were determined. BIS monitoring was decisive in ICU care in 9 of 15 patients in this series. The most significant potential benefit was obtained in the subset of patients receiving NMB.     

Impact of shock requiring norepinephrine on the accuracy and reliability of subcutaneous continuous glucose monitoring

Objective  To evaluate the impact of circulatory shock requiring norepinephrine therapy on the accuracy and reliability of a subcutaneous continuous glucose monitoring system (CGMS) in critically ill patients. Design and setting  A prospective, validation study of a medical intensive care unit at a university hospital was carried out. Methods  Continuous glucose monitoring was performed subcutaneously in 50 consecutive patients on intensive insulin therapy (IIT), who were assessed according to the a priori strata of circulatory shock requiring norepinephrine therapy or not. Results  A total of 736 pairs of sensor glucose (SG)/blood glucose (BG) values were analysed (502 without and 234 with norepinephrine therapy). For all values, repeated measures Bland–Altman analysis showed a mean difference of 0.08 mmol/l (limits of agreement: −1.26 and 1.43 mmol/l). Circulatory shock requiring norepinephrine therapy did not influence the relation of arterial BG with SG in a multivariable random effects linear regression analysis. The covariates norepinephrine dose, body mass index (BMI), glucose level and severity of illness also had no influence. Insulin titration grid analysis showed that 98.6% of the data points were in the acceptable treatment zone. No data were in the life-threatening zone. Conclusions  Circulatory shock requiring norepinephrine therapy, as well as other covariates, had no influence on the accuracy and reliability of the CGMS in critically ill patients.     

脑电双频指数监测对机械通气患者镇静深度评估的研究

目的 观察脑电双频指数(BIS)监测与主观评分的相关性,研究其对机械通气患者镇静深度评估的可行性.方法 将重症监护病房(ICU)需要机械通气的83例患者随机分为两组,设定镇静目标为镇静一躁动评分(SAS)3～4分,分别用BIS(研究组,42例)和SAS(对照组,41例)监测患者的镇静深度,记录两组患者镇静前及镇静后每隔16 h的呼吸、循环指标和BIS、SAS、Ramsay 3种镇静评分,比较组间差异,分析各种评分的相关性.结果 83例患者均达镇静目标,两组间呼吸、循环指标比较差异均无统计学意义(P均>0.05).所有患者镇静后呼吸频率、吸入氧浓度较镇静前显著下降,脉搏血氧饱和度显著升高,差异均有统计学意义(P均<0.05);BIS值与主观评分间相关性良好,其中BIS与SAS评分呈显著正相关(r=0.626,P<0.05),与Ramsay评分呈显著负相关(r=-0.650,P<0.05),SAS与Ramsay评分呈显著负相关(r=0.908,P<0.05).结论 用BIS监测评估机械通气患者镇静深度简单方便、同步有效,是评价ICU机械通气患者镇静深度的良好客观指标.     

脑电双频指数监测对机械通气患者镇静深度评估的研究

目的 观察脑电双频指数(BIS)监测与主观评分的相关性,研究其对机械通气患者镇静深度评估的可行性.方法 将重症监护病房(ICU)需要机械通气的83例患者随机分为两组,设定镇静目标为镇静一躁动评分(SAS)3～4分,分别用BIS(研究组,42例)和SAS(对照组,41例)监测患者的镇静深度,记录两组患者镇静前及镇静后每隔16 h的呼吸、循环指标和BIS、SAS、Ramsay 3种镇静评分,比较组间差异,分析各种评分的相关性.结果 83例患者均达镇静目标,两组间呼吸、循环指标比较差异均无统计学意义(P均>0.05).所有患者镇静后呼吸频率、吸入氧浓度较镇静前显著下降,脉搏血氧饱和度显著升高,差异均有统计学意义(P均<0.05);BIS值与主观评分间相关性良好,其中BIS与SAS评分呈显著正相关(r=0.626,P<0.05),与Ramsay评分呈显著负相关(r=-0.650,P<0.05),SAS与Ramsay评分呈显著负相关(r=0.908,P<0.05).结论 用BIS监测评估机械通气患者镇静深度简单方便、同步有效,是评价ICU机械通气患者镇静深度的良好客观指标.     

脑电双频指数监测对机械通气患者镇静深度评估的研究

目的 观察脑电双频指数(BIS)监测与主观评分的相关性,研究其对机械通气患者镇静深度评估的可行性.方法 将重症监护病房(ICU)需要机械通气的83例患者随机分为两组,设定镇静目标为镇静一躁动评分(SAS)3～4分,分别用BIS(研究组,42例)和SAS(对照组,41例)监测患者的镇静深度,记录两组患者镇静前及镇静后每隔16 h的呼吸、循环指标和BIS、SAS、Ramsay 3种镇静评分,比较组间差异,分析各种评分的相关性.结果 83例患者均达镇静目标,两组间呼吸、循环指标比较差异均无统计学意义(P均>0.05).所有患者镇静后呼吸频率、吸入氧浓度较镇静前显著下降,脉搏血氧饱和度显著升高,差异均有统计学意义(P均<0.05);BIS值与主观评分间相关性良好,其中BIS与SAS评分呈显著正相关(r=0.626,P<0.05),与Ramsay评分呈显著负相关(r=-0.650,P<0.05),SAS与Ramsay评分呈显著负相关(r=0.908,P<0.05).结论 用BIS监测评估机械通气患者镇静深度简单方便、同步有效,是评价ICU机械通气患者镇静深度的良好客观指标.     

脑电双频指数监测对机械通气患者镇静深度评估的研究

目的 观察脑电双频指数(BIS)监测与主观评分的相关性,研究其对机械通气患者镇静深度评估的可行性.方法 将重症监护病房(ICU)需要机械通气的83例患者随机分为两组,设定镇静目标为镇静一躁动评分(SAS)3～4分,分别用BIS(研究组,42例)和SAS(对照组,41例)监测患者的镇静深度,记录两组患者镇静前及镇静后每隔16 h的呼吸、循环指标和BIS、SAS、Ramsay 3种镇静评分,比较组间差异,分析各种评分的相关性.结果 83例患者均达镇静目标,两组间呼吸、循环指标比较差异均无统计学意义(P均>0.05).所有患者镇静后呼吸频率、吸入氧浓度较镇静前显著下降,脉搏血氧饱和度显著升高,差异均有统计学意义(P均<0.05);BIS值与主观评分间相关性良好,其中BIS与SAS评分呈显著正相关(r=0.626,P<0.05),与Ramsay评分呈显著负相关(r=-0.650,P<0.05),SAS与Ramsay评分呈显著负相关(r=0.908,P<0.05).结论 用BIS监测评估机械通气患者镇静深度简单方便、同步有效,是评价ICU机械通气患者镇静深度的良好客观指标.