熵指数与异丙酚镇静深度的相关性研究

目的探讨脑电熵指数与异丙酚全麻诱导时镇静深度的相关性。方法25例ASAⅠ~Ⅱ级择期腹腔镜手术患者,麻醉诱导时异丙酚的给药速度为每1~2 min 0.4 mg/kg直至患者对指令性反应消失。镇静深度的评价按OAA/S镇静评分标准进行评分。结果RE和SE与OAA/S评分相关系数分别为0.7643和0.7372,RE和SE的相关系数为0.974 2;RE和SE均能较好地监测意识的改变,其中RE优于SE;在不同OAA/S评分时RE和SE的值有较大范围重叠。结论脑电熵指数在监测异丙酚镇静深度和意识的消失方面是1个有效的指标。     

老年人脑电双频指数、异丙酚血药浓度与镇静深度的相关性

目的：探讨老年手术患者椎管内麻醉后应用异丙酚镇静,脑电双频指数、异丙酚血药浓度和镇静深度之间的相关性。方法：48例ASAⅠ-Ⅱ级择期手术患者,分为老年组（65-85岁）和年轻组（18-40岁）,每组24例。为尽快达到稳态血药浓度,采用靶控输注方式给药。异丙酚靶浓度从0.5μg/mL起逐渐增加,直至患者对轻推无反应（意识消失）,每个浓度维持5min。连续记录EEG参数,在每一稳态血药浓度末,记录BIS、95%SEF,桡动脉取血（高效液相色谱法测定异丙酚血药浓度）,并评定镇静深度（OAA/S评分法）。用Spearman’s等级相关进行相关分析,并计算预测概率（Pk）值。结果：两组BIS（r=0.935-0.955）与镇静水平的相关性优于血药浓度（r=-0.849-0.870）和95%SEF（r=0.503-0.571）,BIS的Pk值高（0.942-0.972）。在同一镇静评分（OAA/S 41）时,老年组BIS值明显高于年轻组（P〈0.01）,而血药浓度低于年轻组（P〉0.05）。结论：BIS在监测异丙酚镇静水平及预测意识消失方面有重要价值,在同一镇静评分时,老年人BIS值高于年轻人。     

Propofol and non-propofol based sedation for outpatient colonoscopy-prospective comparison of depth of sedation using an EEG based SEDLine monitor

Propofol is a popular anesthetic sedative employed in colonoscopy. It is known to increase the patient satisfaction and improve throughput. However, there are concerns among the clinicians with regard to the depth of sedation, as a deeper degree of sedation is known to increase the incidence of aspiration and other adverse events. So we planned to compare the depth of sedation between propofol and non-propofol based sedation in patients undergoing outpatient colonoscopy, as measured by an electroencephalogram (EEG) based monitor SEDLine monitor (SedlineInc., San Diego, CA). The non-randomized prospective observational study was performed in the outpatient gastroenterology suite of the Hospital of the University of Pennsylvania, Philadelphia. Patients included ASA class I–III aged more than 18 years scheduled for colonoscopy under Propofol or non-propofol based sedation. After an institutional review board approval, a written consent was obtained from prospective patients. Sedation (propofol or non-propofol based) was administered by either a certified nurse anesthetist under the supervision of an anesthesiologist (propofol) or a registered endoscopy nurse under the guidance of the endoscopist performing the procedure (non-propofol sedation). Depth of sedation was measured with an EEG based SEDLine monitor. The sedation providers were blinded to the patient state index—the indicator of depth of sedation. PSI (patient state index—SEDLine reading) was documented at colonoscope insertion, removal and at the return of verbal responsiveness after colonoscope withdrawal. Sedation spectrum was retrieved from the data stored on the SEDLine monitor. Patients sedated with propofol experience significantly deeper degrees of sedation at all times during the procedure. Additionally, during significant part of the procedure, they are at PSI levels associated with deep general anesthesia. The group that received propofol was more deeply sedated and had lower PSI values. Lighter propofol titration protocols may lead to improved patient care such as lowering risk of aspiration and hypotension. The role of processed EEG monitors such as the SEDLine monitor to improve sedation protocols remains to be determined. Trial registration We obtained an ethical clearance from the Institute. No trial registration was mandated, as no interventional drug or investigational device were used during the study.     

Entropy correlates with Richmond Agitation Sedation Scale in mechanically ventilated critically ill patients

Sedation is routinely used in intensive care units. However due to absence of objective scoring systems like Bispectral Index and entropy our ability to regulate the degree of sedation is limited. This deficiency is further highlighted by the fact that agitation scores used in intensive care units (ICU) have no role in paralyzed patients. The present study compares entropy as a sedation scoring modality with Richmond Agitation Sedation Scale (RASS) in mechanically ventilated, critically ill patients in an ICU. Twenty-seven, mechanically ventilated, critically ill patients of either sex, 16–65 years of age, were studied over a period of 24 h. They received a standard sedation regimen consisting of a bolus dose of propofol 0.5 mg/kg and fentanyl 1 μg/kg followed by infusions of propofol and fentanyl ranging from 1.5 to 5 mg/kg/h and 0.5 to 2.0 μg/kg/h, respectively. Clinically relevant values of RASS for optimal ICU sedation (between 0 and ?3) in non-paralyzed patients were compared to corresponding entropy values, to find if any significant correlation exists between the two. These entropy measurements were obtained using the Datex-Ohmeda-M-Entropy? module. This module is presently not approved by Food and Drug Administration (FDA) for monitoring sedation in ICU. A total of 527 readings were obtained. There was a statistically significant correlation between the state entropy (SE) and RASS [Spearman’s rho/r_s = 0.334, p < 0.0001]; response entropy (RE) and RASS [Spearman’s rho/r_s = 0.341, p < 0.0001]). For adequate sedation as judged by a RASS value of 0 to ?3, the mean SE was 57.86 ± 16.50 and RE was 67.75 ± 15.65. The present study illustrates that entropy correlates with RASS (between scores 0 and ?3) when assessing the level of sedation in mechanically ventilated critically ill patients.     

熵指数监测下观察七氟烷在全麻过程中的应用

目的 研究熵指数指导下七氟烷在全麻过程中的应用，并与丙泊酚比较，初步探讨熵指数与OAA/S评分的相关性。方法 选择40例ASAⅠ或Ⅱ级在全麻下行择期腹腔镜下胆囊切除术的患者。随机分为七氟烷组和丙泊酚组，每组20例，麻醉期间分别采用七氟烷、雷米芬太尼和阿曲库铵或丙泊酚，雷米芬太尼和阿曲库铵维持。采用熵指数监测麻醉深度，将熵指数控制在40～60之间，术毕采用镇静/警觉评分OAA/S反映患者全麻后意识恢复程度，并记录到达不同评分的时间及相应熵值（RE和SE）,同时记录麻醉过程中及术毕清醒时对应的心率(HR)、平均动脉压(MAP)、脉搏血氧饱和度(SpO2)、呼气末二氧化碳(PETCO2),并计算比较两组参数的变化情况。 结果 手术维持在同等熵指数下，切皮时两组平均动脉压均高于术前，手术进行至10分钟时丙泊酚组的MAP持续升高，当30分钟时，丙泊酚组的SE值低于七氟烷组。手术结束苏醒时，最终到达OAA/S评分和定向力恢复时间，两组无统计学意义。结论 两组在麻醉维持有效性和安全性及苏醒时间上无明显差别，七氟烷的血流动力学稳定性优于丙泊酚,熵指数与OAA/S评分有良好相关性.     

An assessment of the validity of spectral entropy as a measure of sedation statein mechanically ventilated critically ill patients

Objective To assess whether the Entropy Module (GE Healthcare, Helsinki, Finland), a device to measure hypnosis in anesthesia, is a valid measure of sedation state in critically ill patients by comparing clinically assessed sedation state with Spectral Entropy Design Prospective observational study. Setting Teaching hospital general ICU. Patients and participants 30 intubated, mechanically ventilated patients without primary neurological diagnoses or drug overdose receiving continuous sedation. Interventions Monitoring of EEG and fEMG activity via forehead electrodes for up to 72 h and assessments of conscious level using a modified Ramsay Sedation Scale. Measurements and results 475 trained observer assessments were made and compared with concurrent Entropy numbers. Median State (SE) and Response (RE) Entropy values decreased as Ramsay score increased, but wide variation occurred, especially in Ramsay 4–6 categories. Discrimination between different sedation scores [mean (SEM) P_K value: RE 0.713 (0.019); SE 0.710 (0.019)] and between lighter (Ramsay 1–3) vs.deeper (Ramsay 4–6) sedation ranges was inadequate [P_K: RE 0.750 (0.025); SE 0.748 (0.025)]. fEMG power decreased with increasing Ramsay score but was often significant even at Ramsay 4–6 states. Frequent “on–off” effects occurred for both RE and SE, which were associated with fEMG activity.Values switched from low to high values even in deeply sedated patients. High Entropy values during deeper sedation were strongly associated with simultaneous high relative fEMG powers. Conclusions Entropy of the frontal EEG does not discriminate sedation state adequately for clinical use in ICU patients. Facial EMG is a major confounder in clinical sedation ranges.     

Target-controlled propofol infusion for sedation in patients undergoing transrectal ultrasound-guided prostate biopsy

The efficacy and safety of the routine use of target-controlled infusion of propofol for the sedation of patients undergoing transrectal ultrasound-guided prostate biopsy were assessed. The optimal level of sedation was also evaluated. A total of 250 patients were randomized into five groups according to sedation level determined by the Observer's Assessment of Alertness/Sedation (OAA/S) scale. As the level of sedation was increased, the overall pain and discomfort score decreased and the satisfaction rate tended to increase, although hypoxia meant that intervention occurred more frequently at higher sedation levels. Target-controlled infusion of propofol provided safe and effective sedation during transrectal ultrasound-guided prostate biopsy, particularly if moderate sedation (OAA/S score of 3) was achieved. The effect-site concentration of propofol for this level of sedation was about 1.5 microg/ml.     

A pilot trial of BIS monitoring for procedural sedation in the emergency department

Objective: Procedural sedation is common in the ED. However, there is no objective physiologic parameter available to monitor a patient's conscious state. The Bispectral Index (BIS) monitor has been validated as an objective measure of depth of anaesthesia. We studied the BIS monitor for this role in procedural sedation. Methods: A prospective, observational study with convenience sampling of adult patients in ED who underwent procedural sedation. Patients were treated according to standard practice and sedated as determined by the treating physician. Treating physicians were blinded to the BIS value. BIS values were recorded and compared to the Observer's Assessment of Alertness/Sedation Scale (OAAS). Upon recovery, patients were asked about recall of events while they were sedated. Results: Twelve patients were enrolled and 110 paired readings from 11 patients (7 male) were obtained. It was not possible to obtain readings from one patient. The mean age was 58 years (range 20–94). The Spearman correlation between BIS and OAAS was 0.027 (95% CI ?0.582?0.617). For the three patients who received propofol, the correlation was 1.0. There were no episodes of explicit recall of events during the period of sedation. Conclusions: BIS monitoring is feasible in the ED. Our small study suggests that there is a poor correlation between BIS values and the OAAS scale. Larger studies are required to further explore this relationship. Further developments in brain monitoring technology are also needed before this form of monitoring becomes clinically useful for procedural sedation.     

Nalmefene for elective reversal of procedural sedation in children

Nalmefene is a newer, long-acting opioid antagonist. Its use in children for the elective reversal of emergency department procedures has not been investigated. The objective was to evaluate the safety of nalmefene in children. An open-label pediatric clinical trial was performed. The study was conducted at the emergency department of an urban, university-affiliated children's hospital and consisted of children aged 6 months to 12 years who required procedural sedation where an opioid agent was administered. Patients were excluded if there was altered mental status, history of head trauma, history of opioid allergy, or the anticipated need for opioid agents for pain relief after the procedure. At the completion of the procedure, nalmefene was administered in a dose of 0.25 microg/kg increments (max 10 microg) until sedation was resolved, or to a maximum of 1.0 microg/kg (max 40 microg). Serial ECGs, vital signs, and oxygen saturation were recorded. Sedation was assessed using the Clinical Global Impression Scale (CGIS) at baseline, 2, 4, 6, 8, and 10 minutes after the initial nalmefene dose. The observer's assessment of alertness and sedation (OAA/S) was measured at baseline, 10, 30, 60, 90, and 120 minutes after the first dose of nalmefene. Episodes of resedation were recorded. All patients received follow-up by telephone at 4 and 24 hours after the initial dose of nalmefene to identify any potential late adverse effects. Over the study interval 15 patients were enrolled. Mean age was 59.1 +/- 41.5 months. Procedures involved fracture reduction (n=8), laceration repair (n = 4), abscess drainage (n = 2), and arthrocentesis (n = 1). All patients received IV fentanyl and midazolam. The mean dosage of fentanyl and midazolam was 3.21 +/- 1.03 microg/kg and 0.07 +/- 0.03 mg/kg, respectively. The mean dose of nalmefene at the time of complete response (CGIS = 1 or 2) was 0.55 +/- 0.29 microg/kg. The median number of nalmefene doses was 2. All but one patient (93%) had a complete response based on CGIS at 10 minutes after the initial dose of nalmefene was given. Nalmefene resulted in a significant improvement in CGIS (1.60 +/- 0.82 v 3.26 +/- 0.88, P =.001) and OAA/S (median score 5 v 4) when compared at baseline with 10 minutes after the initial dose of nalmefene. Nalmefene also resulted in increased diastolic blood pressure (62.6 +/- 10.5 v 55.8 +/- 10.7, P =.04) as well as improved oxygen saturation when compared at 120 minutes to baseline (99.5 +/- 0.74% v 98.5 +/- 0.4%, P =.03). There were no significant changes in pulse, systolic blood pressure, respiratory rate, and ECG. None of the patients became resedated after nalmefene was given. One patient developed nausea and vomiting within the first 2 hours after nalmefene; this resolved without intervention before discharge. No adverse events occurred in any of the patients at 4 and 24 hours postadministration. The results of this study showed that nalmefene is effective and safe for reversal of procedural sedation by opioids in children.     

Patient State Index (PSI) measures depth of sedation in intensive care patients

Objective To investigate whether the electroencephalogram (EEG)-based Patient State Index (PSI) indicates the level of sedation as measured by Ramsay score in intubated and mechanically ventilated patients in the ICU.Design Prospective, single-blinded observer study.Setting Surgical intensive care unit.Patients Forty-one consecutive adult patients requiring intubation and ventilation during intensive care therapy.Measurements and results Following skin preparation with alcohol and placement of EEG electrodes, PSI was recorded while patients were ventilated and sedated with constant drug infusion rates. After 30 min, the level of sedation was measured by an assessor, who was blinded to PSI values, using the Ramsay sedation score. For analysis, the mean of PSI values measured during the last minute before clinical assessment of sedation was calculated. General Linear Model (GLM) analysis revealed significant differences between the PSI values at different levels of sedation as measured by the Ramsay score, except for the differentiation of level 5 from levels 4 and 6 (p>0.3) and level 2 from level 3, where only a trend was reached (p=0.077). The prediction probability of PSI was 0.920±0.037.Conclusion As the high prediction probability and the analysis of paired comparisons suggest, PSI may be used to quantify the level of propofol/sufentanil sedation in ICU patients. Further studies are required to test whether these promising results can be verified for other drug combinations.This work was financed from departmental sources and supported by a grant from B. Braun AG, Melsungen, Germany.     

Comparative evaluation of the bispectral index (BIS) and BISpro during propofol anaesthesia

ObjectiveTo compare the accuracy, correlation and agreement between the bispectral index (BIS) and BISpro during propofol anaesthesia.MethodsThe BIS, BISpro, heart rate, target-concentration of propofol and Observer’s Assessment of Alertness and Sedation (OAA/S) score were recorded every 30 s in female patients scheduled for hysteroscopic surgery. Propofol anaesthesia was induced by an initial target-controlled concentration (1.0 μg/ml) followed by a stepwise increase (0.5 μg/ml) until the patient was unresponsive. Spearman’s correlation coefficient and prediction probability were calculated for the association between sedation levels and the above parameters. The ability of investigated parameters to distinguish between OAA/S scores was analysed. Bland–Altman analysis was used to compare the agreement between BIS and BISpro. The BIS and BISpro cut-off values for lost response were also determined.ResultsOut of 30 patients in total, a high correlation was found between BIS and BISpro, and both correlated well with OAA/S score. Only BIS was able to distinguish all investigated OAA/S states accurately, but the ability to predict OAA/S score 5 to loss of response was comparable between BIS and BISpro. The calculated cut-off values were 68 for BIS and 70 for BISpro.ConclusionBISpro and BIS are reliable monitors of general anaesthesia during sedation.Trial registration number: Chinese Clinical Trial Registry (URL: www.chictr.org.cn): ChiCTR1900024037 (retrospectively registered).     

Comparing Entropy and the Bispectral Index with the Ramsay Score in Sedated ICU Patients

Objective

ENTROPY? is a new anesthetic depth monitor based on the analysis of the EEG signal. Our aim has been to evaluate sedation of intubated surgical critically ill patients by means of the Ramsay sedation score, the Bispectral index and ENTROPY?, and to analyse the correlation between these variables.

Methods

Sedation was evaluated every 15 min for a 1 h period in 50 non-paralysed postoperative critically ill, intubated patients, enrolled over a 6 month period. A 5 min steady-state period was allowed before each assessment. Both the Bispectral index and the Entropy parameters Response Entropy (RE) and State Entropy (SE), were collected before assessing the Ramsay scale.

Results

Mean values for SE, RE and BIS were 53 ± 27, 60 ± 30, and 62 ± 24 respectively. The median value for the Ramsay was 6 (range 1–6). Significant correlation was found between the four variables (SE-BIS: r = 0.79, p < 0.001; RE-BIS: r = 0.80, p < 0.001; SE-Ramsay: ρ = ?0.71, p < 0.001, RE-Ramsay: ρ = ?0.72, p < 0.001; BIS-Ramsay: ρ = ?0.78, p < 0.001; RE-SE: r = 0.98, p < 0.001). An overlap of BIS and Entropy values for every Ramsay score value between 4–6 was found.

Conclusions

ENTROPY?, BIS and Ramsay score values correlate significantly in sedated postoperative ICU patients. ENTROPY? does not appear superior to BIS for the assessment of sedation in this context.

     

Propofol versus midazolam for conscious sedation guided by processed EEG during endoscopic retrograde cholangiopancreatography: a prospective, randomized, double-blind study

BACKGROUND AND STUDY AIMS: Endoscopic retrograde cholangiopancreatography (ERCP) is a complex procedure, which requires appropriate sedation. The aim of this prospective, randomized, double-blind study was to compare the quality and characteristics of sedation with midazolam or propofol in patients undergoing ERCP. PATIENTS AND METHODS: A total of 32 patients undergoing ERCP were randomly allocated for sedation with propofol (n = 15) or midazolam (n = 17). Blood pressure, heart rate, and O2 saturation were monitored. Sedation was maintained at near constant levels by use of the spectral edge frequency (SEF) technique, an EEG-based method for measuring the depth of sedation. Clinical variables, patient cooperation, time to recovery, and amnesia served as outcome variables. RESULTS: There was no significant difference between the two study groups in patient characteristics. The "target SEF" was 13.6 +/- 0.7 Hz for the propofol group and 14.8 +/- 1.1 Hz for the midazolam group (n.s.). The only clinical parameter with a significant difference between the groups was the percent of time in which the heart rate deviated more than 20% from baseline for at least 2 minutes, i.e. 14.6 +/- 2.0 % for propofol and 48.2 +/- 38.0% for midazolam (P<0.01). Patient cooperation was better in the propofol group than in the midazolam group (full cooperation, 13/15 vs. 1/17, respectively; P<0.001). Patient recovery was significantly quicker in the propofol group (P<0.001). The degree of amnesia was similar in both groups; no patient in either group remembered details of the procedure. CONCLUSIONS: ERCP is better tolerated by patients sedated with propofol compared with midazolam, with a shorter recovery time and lesser hemodynamic side effects. Propofol should be considered to be the sedative drug of choice for ERCP.     

脑电双频指数监测在重症加强治疗病房机械通气患者镇静中的应用

目的探讨脑电双频指数(BIS)实时监测在重症加强治疗病房(ICU)机械通气患者镇静中应用的可行性。方法选取30例术后机械通气患者,静脉注射咪唑安定或异丙酚达到合理镇静,采用盲法对患者每隔5min分别记录1次Ramsay镇静分级评分及BIS。比较Ram say镇静分级评分对应BIS中位数的总体差异,分析BIS结果与Ram say镇静分级评分的相关性。计算BIS的敏感度和约登(Youden)指数,确定BIS监测的敏感度和特异度。结果随镇静深度的加深,BIS明显降低,Ramsay分级评分对应的BIS中位数之间差异有显著性(P<0.01);BIS与Ram say分级评分呈负相关(r=-0.794,P<0.01);Ram say分级评分2~5分(为合理镇静)时对应的BIS中位数的95%可信区间(参考值范围)为61~84;当BIS值为81时,BIS监测从镇静合理到镇静不足的Youden指数和敏感度最高;Ram say分级评分为6分(为镇静过度)时对应的BIS中位数的95%可信区间为48~58。结论BIS监测与Ram say镇静分级具有良好的相关性,能实时、客观地监测ICU机械通气患者的镇静状态,并指导镇静治疗。     

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。     

Frontal EEG for intensive care unit sedation: treating numbers or patients?

In this issue of Critical Care, Dr Haenggi and co-workers present a study evaluating bispectral index (BIS), state entropy (SE) and response entropy in 44 patients sedated in the intensive care unit (ICU). As in recent studies attempting to correlate frontal electroencephalogram (EEG) measurements with clinical evaluations of sedative efficacy, there is considerable overlap in numerical EEG values and different clinical levels of sedation. This precludes the use of these monitors for monitoring or titrating sedation in the critically ill. Despite many attempts, no study has yet presented data showing improved outcome with the use of EEG monitors in ICU sedation. Meanwhile, clinical sedation protocols have emerged, improving important endpoints in critically ill patients needing sedation. A major underlying problem in applying EEG monitors in the ICU is that they have been developed for measuring anesthetic depth and the related risk of recall, rather than the acknowledged endpoints of sedation, namely reduction of anxiety and discomfort. Until an 'objective' monitor is developed to measure the degree of such symptoms, physicians should continue treating patients and not numbers.     

Bi-spectral index,entropy and predicted plasma propofol concentrations with target controlled infusions in Indian patients

Objective

Many processed electroencephalographic signals are used now to help the anaesthesiologist titrate the depth of sedation. We investigated the relationship between target plasma propofol concentration and objective end-points of sedation— Bispectral Index (BIS), State Entropy (SE) and Response Entropy (RE)—at clinical end-points as assessed by Modified Observer Assessment of Alertness/sedation Scale (MOAAS) in Indian patients.

Methods

Eighteen ASA 1 and 2 Indian adult patients scheduled to undergo elective surgery were included. The target control infusion (TCI) of propofol was administered using ‘Diprifusor’. The level of sedation was assessed using MOAAS by the anaesthesiologist. BIS, SE, RE were recorded throughout. TCI was started at 0.5 μg/ml and increased by 0.5 μg/ml every 6 min till MOAAS scores reached 0 or there was sustained BIS value less than 30.

Results

The EC₅₀ and EC₉₅ of predicted plasma propofol concentration for loss of consciousness (assessed by loss of response to verbal command), were 2.3 and 2.8 μg/ml respectively and for loss of response to painful stimuli (trapezius squeeze) were 4.0 and 5.0 μg/ml respectively. The BIS and entropy values (EC₅₀ and EC₉₅) for loss of consciousness and response to painful stimuli in Indian patients were estimated. The preliminary relation of target plasma propofol concentration with BIS was found to be BIS = 100.5–16.4?×?(Target concentration).

Conclusions

The target plasma propofol concentrations required to produce unconsciousness and loss of response to painful stimuli in Indian patients have been estimated. Also, the relations between target plasma concentration and objective measures of different levels of anaesthesia have been established.

     

Impact of the United States propofol ban on emergency providers’ procedural sedation agent choice and patient length of stay

BACKGROUND:

In the recent past, propofol was temporarily removed from the emergency department (ED) for use in procedural sedation. We sought to determine which agents replaced it in clinical practice and the impact this change had on turnaround times (TAT) for sedated patients.

METHODS:

This study is a retrospective chart review at a level one trauma center. Patients receiving sedative agents (propofol, ketamine, midazolam, and etomidate) were identified by pharmacy codes, and their charts were then reviewed for demographics and TAT. Propofol was unavailable in the emergency department (ED) between May 2010 and February 2011. The study period extended from May 2009 until May 2011. Patients receiving sedation by non-emergency medicine physicians and those receiving sedation related to intubation were excluded.

RESULTS:

In total 2466 charts were reviewed and 209 met inclusion criteria. When propofol was available, the most commonly used sedative agent was etomidate (40%), followed by propofol (28%), ketamine (20%), and midazolam (6%). When propofol was unavailable, etomidate remained the most commonly used agent (43%), followed by ketamine (41%), and midazolam (11%). When propofol was available, the median TAT for sedated patients was 163 minutes compared to 178 minutes when propofol was unavailable (P=0.83). When propofol was the primary sedative agent used, the median TAT was 166 minutes as compared with a median TAT of 172 minutes for all other sedative agents combined (P=0.87).

CONCLUSION:

When propofol was unavailable, ketamine became a preferred ED sedation agent. Removal of propofol from the sedation armamentarium did not affect ED TAT.KEY WORDS: Procedural sedation, Turnaround time, Propofol, Ketamine, Etomidate, Midazolam     

Propofol versus Midazolam/Fentanyl for Reduction of Anterior Shoulder Dislocation

OBJECTIVE: The authors aimed to compare propofol and midazolam/fentanyl for reduction of anterior shoulder dislocations using the modified Kocher's maneuver. METHODS: This was a multicenter, randomized, clinical trial of patients with anterior shoulder dislocation. Patients were randomized to either propofol or midazolam/fentanyl. The randomized drug was titrated to a clinical sedation end point (spontaneous eye closure). One physician sedated the patient. Another, blinded to the drug administered, reduced the shoulder and recorded details of muscle tone and ease of reduction. RESULTS: Eighty-six patients were randomized to treatment with propofol (n = 48) or midazolam/fentanyl (n = 38). Patients in the propofol group had shorter mean times to first wakening (difference in means, 4.6 minutes; 95% confidence interval [CI] = 0.7 to 8.6; p = 0.097) and full consciousness (difference in means, 21.7 minutes; 95% CI = 14.7 to 28.7; p <0.001), had easier shoulder reduction (difference in mean rating, 0.5; 95% CI = 0.0 to 0.9; p = 0.047), and needed fewer reduction attempts (difference in means, 0.5; 95% CI = 0.1 to 1.0; p = 0.02). Patients in the propofol group also had less mean muscle tone at the first reduction attempt (p = 0.08) and needed fewer reduction maneuvers (p = 0.40) but had more respiratory depression (11 vs. six patients; difference in proportions, 7.1%; 95% CI = -11.8 to 26.1; p = 0.58) and had one patient who vomited. CONCLUSIONS: Propofol appears to be as effective as midazolam/fentanyl for reduction of anterior shoulder dislocation using the modified Kocher's maneuver. However, the advantage of shorter wakening times associated with propofol should be weighed against the possibility of adverse events, particularly respiratory depression and vomiting.     

Intensive care sedation: a review of current British practice

Objective: Sedation is central to the management of intensive care patients. Many different techniques have been tried, all have potential side effects, and some have been associated with serious adverse effects. The aim of this work is to establish current sedation practice in British ICUs; the use of neuromuscular blocking drugs and the indications for their use, the use of sedation policies and scoring systems, the influence of cost on drug choice, and the use of propofol for sedation in paediatric patients. Design: A postal survey sent to all units identified in the Directory of Emergency Services. Results: Two hundred and fifty-five replies were received from 323 questionnaires (79 % response rate). The replies show that alfentanil, morphine, midazolam, and propofol are the most widely used drugs for sedation, and that changes occur in sedation policy with the time a patient spends in intensive care. Atracurium is the most widely used neuromuscular blocking drug, but the number of patients who receive therapeutic paralysis is relatively small and the indications for its use in different units is consistent. Propofol is used by many ICUs for the sedation of children despite reports linking its use to mortality in children and the advice of the regulatory authorities. Conclusions: Drugs used for the sedation of patients in intensive care have changed since previous surveys. The sedation policy of most units relies on the combination of small numbers of drugs. Sedation policies now seem to concentrate on achieving a lightly sedated co-operative patient. Received: 13 August 1999/Final revision received: 18 April 2000/Accepted: 26 April 2000