脉搏灌注指数变异监测机体容量状况的临床研究

目的 评估脉搏灌注指数变异(PVI)在全身麻醉机械通气条件下预测患者容量治疗反应、评估容量状况的能力.方法 2009年8月至11月选择25例美国麻醉医师协会分级Ⅰ～Ⅱ级拟在全身麻醉下行腹部手术的患者,年龄25～74岁,麻醉诱导后连续监测平均动脉压、心率、中心静脉压、心指数(CI)、每搏输出量变异度(SW)、PVI、灌注指数(PI)等血流动力学指标,以0.4 ml·kg-1·min-1的速率静脉输注6%羟乙基淀粉(130/0.4)注射液,输注总量:7 ml/kg,将CI增加百分比(△CI)≥15%视为对容量治疗有反应.结果 对容量治疗有反应的患者SVV基础值16.0%±2.6%显著高于对容量治疗无反应患者的11.6%±1.4%(P＜0.05);对容量治疗有反应的患者PVI基础值20.5%±3.7%也显著高于对容量治疗无反应患者的13.8%±2.6%(P＜0.05);SVV诊断阈值为13.5%,监测容量反应的灵敏度为88.2%,特异度为87.5%;PVI的诊断阈值为15.5%,监测容量反应的灵敏度为88.2%,特异度为87.5%;Pearson相关性分析显示:SVV的基础值与△CI相关系数r=0.600(P＜0.01),PVI的基础值与△CI相关系数r=0.683(P＜0.01).结论 PVI,脉搏灌注指数周期性的变异能够预测机械通气患者在安静状态下的容量治疗反应,其准确性与有创测得的SVV相类似.     

超声测量下腔静脉呼吸变异度预测膝关节镜手术驱血引起的容量变化

目的分析下腔静脉呼吸变异度(inferior vena cava respiratory variation index,IVC‑RVI)预测膝关节镜手术驱血引起的容量变化,为临床预测驱血所引起容量变化提供帮助。方法选取2018年10月至2019年7月间全身麻醉下膝关节镜手术患者85例为研究对象,所有患者均使用驱血带进行驱血。记录所有患者驱血前IVC‑RVI和驱血前后的心率、MAP、每搏输出量(stroke volume,SV)。以每搏变异度(stroke volume variability,SVV)≥15%作为评价有容量反应性的金标准,将所有患者分为有容量反应性(CR)组和无容量反应性(NCR)组。分析IVC‑RVI与SVV相关性,绘制IVC‑RVI预测CR的受试者工作特征(receiver operating characteristic,ROC)曲线,计算曲线下面积(area under the curve,AUC)、Youden指数、敏感度和特异性。结果患者IVC‑RVI与SVV呈线性正相关关系(r=0.655,P<0.05)。IVC‑RVI预测CR的AUC为0.899(95%CI=0.835~0.963,P<0.05)。IVC‑RVI预测切点为17.3%,预测敏感度79.2%,特异性86.5%。结论全身麻醉下膝关节镜手术中,IVC‑RVI可有效预测驱血所引起容量变化,具有一定的临床应用价值。     

以心指数/每搏指数/每搏量变异度为导向的老年患者开胸肺叶切除术液体管理的临床研究

目的 观察以心指数/每搏指数/每搏量变异度(cardiac index/stroke volume index/stroke volume variation,CI/SVI/SVV)为导向的液体管理策略对行开胸肺叶切除术的老年患者术后转归的影响.方法 30例行择期肺叶切除术的患者,年龄≥65岁,美国麻醉医师协会(ASA)分级Ⅰ～Ⅱ级,采用随机数字表法随机分为以CI/SVI/SVV为导向的S组(15例)和以中心静脉压(central venous pressure,CVP)为导向的C组(15例),监测围术期两组指标,包括心率(heart rate,HR)、平均动脉压(mean arterial pressure,MAP)、动脉血氧饱和度(arterial oxygen saturation,SpO2)、呼气末二氧化碳分压(end-tidal carbon dioxide partial pressure,PETCO2)、气道压力(airway pressure,Pmax)、脑电双频指数(bispectral index,BIS)等,评价以CI/SVI/SVV为导向的围术期液体管理策略在改善患者术后转归方面是否优于传统的以CVP为指导的液体管理策略. 结果 S组患者术中不同观察时间点HR、MAP、SpO2、PETCO2、Pmax、BIS与C组比较差异无统计学意义.S组患者术中输液量(1 310±310) ml、术后液体输入的正平衡量(516±412) ml明显小于C组患者(1 820±459)、(757±667) ml(P＜0.05),术后重症监护室(ICU)驻留时间、氧合指数等指标S组较C组呈现良好的转归趋势.C组患者术后高血压的发生率(40％)明显高于S组(6.67％)(P＜0.05),余无特殊.结论 以CI/SVI/SVV为导向的老年胸科手术围术期液体管理策略较传统的以CVP为导向的液体管理具有创伤小、操作简便、液体管理更具个性化等优点,有助于改善老年患者术后转归.     

围术期循环容量监测的动态指标及其研究进展

背景大量研究表明围术期加强循环容量监测、目标导向液体治疗（goal-directed fluid therapy,GDT）可以减少术后并发症,改善患者预后。每搏输出量变异度（stroke volume variation,SVV）、脉压差变异度（pialse pressure variation,PPV）、脉搏灌注变异指数（pleth variability index,PVI）、PPV／SVV比值等动态指标可以预测容量反应性,指导患者容量治疗的能力优于静态指标。目的探讨动态参数指导容量治疗的可靠性和影响因素。内容动态指标易受潮气量、血管张力、体位等多种因素影响,而且患者心律失常、非机械通气时动态参数没有应用价值。另外,容量治疗的目标是保证组织灌注和氧供,不能单纯依靠某一参数变化进行评价。因此,应结合患者其他血流动力学参数、相关实验室指标及临床转归等综合判断。趋向动态指标对预测液体治疗效果具有很好的指导意义和广阔的应用前景,其对脑组织等灌注的评估能力仍需进一步研究。     

每搏输出量变异度监测非体外循环冠状动脉旁路移植术患者血容量变化的准确性

目的 评价每搏输出量变异度(SVV)监测非体外循环冠状动脉旁路移植术患者血容量变化的准确性.方法 择期行非体外循环冠状动脉旁路移植术患者21例,性别不限,年龄44～77岁,体重43～93 kg,ASA分级Ⅱ或Ⅲ级.开胸打开心包,待血液动力学稳定5 min时(T1),以0.25ml·kg-1·min-1的速率静脉输注6％羟乙基淀粉130/0.4氯化钠注射液7 ml/kg.于T1和输注完毕后10min(T2)时记录HR、MAP、CVP、体循环血管阻力(SVR)、体循环血管阻力指数(SVRI)、SVV、每搏输出量指数(SVI)和CI,并计算变化率(△HR、△MAP、△CVP、△SVR、△SVV、△SVI和△CI).△HR、△MAP、△CVP、△SVR、△SVV与△SVI进行Pearson相关性分析.以△SVI≥25％为扩容有效的标准,绘制HR、MAP、CVP、SVR、SVV监测血容量变化的ROC曲线,计算曲线下面积及其95％可信区间.结果 与T1时比较,T2时CVP、SVI、CO和CI升高,SVRI和SVV降低(P＜0.01),MAP和HR差异无统计学意义(P＞0.05).△HR、△SVR与△SVI均呈负相关,相关系数分别为-0.737和- 0.480(P＜ 0.05)；△CVP、△MAP、△SVV与△SVI无相关性(P＞0.05).ROC曲线分析结果显示:SVV的诊断阈值为8.8％,灵敏度为52.6％,特异度为100.0％.ROC曲线下面积及其95％可信区间为0.579(0.346 ～ 0.812).结论 SVV不能准确地监测非体外循环冠状动脉旁路移植术患者的血容量变化.     

非心肺转流冠状动脉旁路移植术中心脏循环效率变化趋势的分析

目的采用压力波形分析技术(pressure recording analytical method,PRAM)分析非心肺转流冠状动脉旁路移植术(off-pump coronary artery bypass grafting,OPCABG)中心脏循环效率(cardiac cycle efficiency,CCE)等血流动力学参数的变化趋势。方法选择2017年3—9月拟于全麻下行择期OPCABG患者43例,男36例,女7例,年龄45~75岁,ASAⅡ或Ⅲ级,心功能Ⅱ或Ⅲ级。应用MOSTCARE监护仪(核心技术为PRAM)监测患者麻醉结束后(T_1)、吻合前降支(T_2)、吻合对角支(T_3)、吻合回旋支(T_4)、吻合后降支(T_5)、搭桥完成后(T_6)、术毕(T_7)时的血流动力学参数,包括CCE、最大压力梯度(dp/dt)、MAP、HR、心脏指数(cardiac index,CI)、每搏指数(stroke volume index,SVI)、心搏量变异度(stroke volume variability,SVV)、外周血管阻力指数(systemic vascular resistance index,SVRI)。结果与T_1时比较,T_2—T_6时CCE明显降低(P0.01),且CCE在以上时点均下降为负值,T_5时下降至最低。与T_1时比较,T_2—T_7时dp/dt、CI、SVI、SVRI明显降低(P0.05);HR明显增快,SVV明显升高(P0.05),但仍处于正常范围内。T_2—T_6时CCE与dp/dt呈明显正相关(P0.05);T_1—T_4、T_7时CCE与CI、SVI呈明显正相关,与SVRI呈明显负相关(P0.01);T_1、T_7时CCE与SVV呈明显负相关(P0.01)。结论在靶血管吻合过程中,尽管CI、SVI、SVRI等参数仍在正常范围,但CCE却有明显降低并至负值,吻合后降支时降至最低,且恢复较其他血流动力学参数缓慢。     

脉搏灌注指数变异在复合麻醉术中诊断价值的研究

目的:比较全身麻醉(G)与全身麻醉复合硬膜外麻醉(GE)术中脉搏灌注指数变异(pleth variation index,PVI)对预测容量治疗反应性的诊断价值。方法:择期肝脏部分切除术病人56例,分为单纯G组和GE组。麻醉诱导后,G组病人硬膜外给予生理盐水,GE组病人给予0.5%布比卡因10 mL,手术开始20 min后,以6%羟乙基淀粉130/0.4氯化钠注射液250 mL快速扩容。记录用药前、硬膜外给药20 min后扩容前及扩容后3 min的PVI及心指数(cardic index,CI)。以△CI≥15%作为容量治疗有效的判断标准,对两组病人的PVI进行受试工作特征曲线分析,比较各时间点PVI的变化。结果:G组PVI监测容量治疗反应性的诊断阈值为12%,灵敏度和特异度分别为87.50%及83.33%,受试工作特征曲线下面积为0.88。GE组PVI的诊断阈值为7%,灵敏度为47.06%,特异度为33.33%,受试工作特征曲线下面积为0.39,不具备预测术中容量治疗反应性的价值。结论:GE中PVI预测容量治疗反应性的价值较单纯G显著降低。     

MostCare监测SVV和PPV预测头低截石位宫腹腔镜手术患者容量反应的准确性

目的:探讨MostCare监测每搏量变异度（stroke volume variation, SVV）和脉压变异率（pulse pressure variation, PPV）预测头低截石位宫腹腔镜手术患者容量反应的准确性。方法:选择30例择期行宫腹腔镜手术的全身麻醉患者,ASA分级Ⅰ、Ⅱ级,年龄40~60岁。采用Mo...     

目标容量填充对沙滩椅位下骨科肩关节镜手术患者血流动力学的影响

目的评价FloTrac/Vigileo系统监测常规容量填充和目标靶控容量填充对沙滩椅位(beach chair position,BCP)下骨科肩关节镜手术患者血流动力学的影响。方法选择择期行肩部关节镜手术患者30例,男17例,女13例,年龄18~65岁,体重49~68kg,ASAⅠ或Ⅱ级,随机分为两组:常规容量填充组(R组)和FloTrac/Vigileo指导下目标靶控容量填充组(S组),每组15例。R组麻醉诱导后30 min内予以10 ml/kg羟乙基淀粉130/0.4快速静滴行容量填充;S组使用FloTrac/Vigileo系统监测MAP、每搏变异度(SVV)、每搏输出量指数(SVI)和心脏指数(CI),当SVV13%时,5min内静注3 ml/kg羟乙基淀粉130/0.4氯化钠注射液后观察各项指标变化,当SVV13%,观察CI变化(1)CI2.5L·min-1·m-2时,给予多巴胺0.5~1μg·kg-1 min-1,至CI2.5L·min-1·m-2;(2)若CI2.5L·min-1·m-2,不予处理,观察SVV、MAP、CI的变化。记录麻醉诱导前(T1)、诱导后3min(T2)、BCP时(T3)、BCP后5 min(T4)、30 min(T5)以及手术结束平卧位(T6)的MAP、HR、CI、SVI、SVV;记录两组患者麻醉期间血管活性药物的用量、术中用于容量填充的胶体液用量、胶体液总量以及液体总量;记录患者不良反应的发生情况。结果与T1时比较,T3~T5时两组MAP、CI、SVI明显降低(P0.05);与T2时比较,T3~T5时R组SVV明显升高(P0.05)。T3~T5时S组MAP、CI、SVI明显高于R组,而SVV明显低于R组(P0.05)。S组术中用于容量填充的胶体液用量、胶体液总量以及液体总量明显多于R组(P0.05),两组晶体液总量差异无统计学意义。S组术中麻黄碱、多巴胺用量、尿量明显少于R组,低血压发生率明显低于R组(P0.05)。结论以MAP、CI、SVV为目标靶控容量填充模式较传统容量填充可更为安全有效稳定BCP引起的血流动力学波动。     

气腹对腹腔镜输尿管切开取石术患者每搏变异度和脉搏灌注变异指数的影响

目的观察CO₂气腹对腹腔镜输尿管切开取石术患者每搏变异度（SVV）和脉搏灌注变异指数（PVI）的影响。方法择期全麻下行腹腔镜输尿管切开取石术患者70例,常规麻醉诱导后气管插管,控制呼吸,潮气量10ml/kg,呼吸频率8-12次/分。于气腹前以及气腹后两个时间点采用FloTrac/Vigileo系统测量SVV,同步采用Masimo Radical 7脉搏血氧仪测量PVI。结果与气腹前比较,气腹后患者SVV、PVI值升高,具有统计学意义（P<0.05）。相关性分析显示:气腹前后SVV、PVI分别与CO呈负相关（依次为r=-0.619,P<0.01;r=-0.753,P<0.01）;而PVI与SVV均呈正相关（r=0.638,P<0.01）。结论 CO₂气腹后SVV、PVI均显著升高,且与气腹前后两者之间存在显著的线性相关性,但气腹不影响PVI与SVV的良好相关性。     

不同潮气量通气患者液体治疗时每搏量变异度判断扩容效应的阈值

目的 确定不同潮气量通气患者液体治疗时每搏量变异度(SVV)判断扩容效应的阈值.方法 拟在全麻下行胃肠手术的患者50例,ASA分级Ⅰ或Ⅱ级,年龄20～75岁,随机分为2组(n=25):潮气量8 ml/kg组(V1组)和潮气量10 ml/kg组(V2组).麻醉诱导后以0.4 ml·kg-1·min-1的速率静脉输注6%羟乙基淀粉130/0.4氯化钠注射液,输注量7 ml/kg.于液体治疗前即刻(T1)和液体治疗结束后3 min(T2)时记录MAP、HR、CVP、CI、SVV、每搏指数(SVI)、体循环血管阻力指数(SVRI),计算SVV和CI的变化率(△SVV和△CI).以△CI≥15%为扩容有效标准,绘制SVV判断扩容效应的ROC曲线,确定诊断阈值.结果 ROC曲线分析结果:V1组SVV的诊断阈值为10.5%,判断扩容有效的灵敏度为93.3%,特异度为75.0%;V2组SVV的诊断阈值为13.5%,判断扩容有效的灵敏度为87.5%,特异度为85.7%;V1组SVV判断扩容有效的ROC曲线下面积及其95%可信区间为0.946(0.860～1.031),V2组为0.951(0.868～1.034).V1组和V2组△SVV与△CI呈负性相关,相关系数分别为-0.553和-0.602(P＜0.01).结论 潮气量为8 ml/kg和10 ml/kg机械通气下,SVV判断患者液体治疗时扩容有效的阈值分别为10.5%和13.5%.     

Stroke volume variation as a predictor of fluid responsiveness in patients undergoing airway pressure release ventilation

We investigated the effectiveness of stroke volume variation (SVV) shown by the Vigileo-FloTrac? system (Edwards Lifesciences, Irvine, CA) to predict fluid responsiveness in patients undergoing airway pressure release ventilation (APRV). All 80 patients mechanically ventilated in the intensive care unit of our hospital from April to November 2010 were included in this study. After starting APRV, Ringer's lactate solution was administered for 30 minutes. Haemodynamic variables including heart rate, mean arterial pressure, cardiac index (CI), stroke volume index (SVI) and SVV were measured before and after volume loading. SVV before volume loading was significantly correlated with absolute change in SVV (ΔSVV) and percentage change in stroke volume index (ΔSVI) after volume loading (ΔSVV: P<0.05, r2=0.534; ΔSVI: P<0.05, r2=0.217). Of the 80 patients, 38 (47.5%) were responders to intravascular volume expansion (increase in CI≥15%) and 42 (52.5%) were non-responders (increase in CI<15%). Receiver operating characteristic (ROC) curves were generated for SVV and central venous pressure by varying the discriminating threshold of the variable and areas under the ROC curves were calculated. The areas under the ROC curves were 0.793 for SVV (95% confidence interval: 0.709-0.877) and 0.442 for central venous pressure (95% confidence interval: 0.336-0.549), which were significantly different (P<0.05). The optimal threshold value of SVV to discriminate between responders and nonresponders was 14% (sensitivity: 78.9%; specificity: 64.3%). We found that SVV was able to predict fluid responsiveness in patients undergoing APRV with acceptable levels of sensitivity and specificity.     

Prediction of volume responsiveness using pleth variability index in patients undergoing cardiac surgery after cardiopulmonary bypass

Background

The pleth variability index (PVI) is derived from analysis of the plethysmographic curve and is considered to be a noninvasive parameter for prediction of volume responsiveness. The aim of our prospective clinical study was to evaluate if volume responsiveness can be predicted by PVI in patients undergoing cardiac surgery after cardiopulmonary bypass.

Methods

Eighteen patients were prospectively studied. Directly after cardiac surgery, PVI, stroke volume variation (SVV), and cardiac index (CI) were recorded. Colloid infusion (4?ml/kg body weight) was used for volume loading, and volume responsiveness was defined as increase of CI more than 10?%.

Results

SVV and PVI measures were found to be highly correlated at r?=?0.80 (p?<?0.001). Receiver operating characteristics curve (ROC) analysis resulted in an area under the curve of 0.87 for SVV and 0.95 for PVI, which values did not differ statistically significant from each other (p?>?0.05). The optimal threshold value given by ROC analysis was ≥11?% for SVV with a sensitivity and specificity of 100?% and 72.2?%. For PVI, optimal threshold value was ≥16?% with a sensitivity and specificity of 100?% and 88.9?%. Positive and negative predictive values estimating an increase of CI ≥10?% for SVV were 44.4?% and 100?% and 66.7?% and 100?% for PVI.

Conclusions

For consideration of fluid responsiveness PVI is as accurate as SVV in patients after cardiopulmonary bypass. Methodological limitations such as instable cardiac rhythm after cardiopulmonary bypass and right- or left ventricular impairment seem to be responsible for low specificity and positive predictive values in both parameters PVI and SVV.     

硬膜外局部麻醉药物中添加去氧肾上腺素对老年患者血流动力学影响的初步研究

目的 观察硬膜外局部麻醉药物中添加去氧肾上腺素对老年患者血流动力学的影响.方法 选择30例ASA分级Ⅰ、Ⅱ级,择期硬膜外麻醉下进行全髋或半髋关节置换术的老年患者,按随机数字表法分为对照组和观察组(每组15例).对照组硬膜外局部麻醉药为利多卡因(2％利多卡因17 ml+生理盐水3 ml,不添加血管活性药物),观察组硬膜外局部麻醉药为添加15 mg/L去氧肾上腺素的利多卡因(2％利多卡因17 ml+100 mg/L去氧肾上腺素3ml).记录硬膜外给药前1 min(T0)和麻醉后5 min (T1)、15 min (T2)、30 min (T3)、60 min (T4)及术毕时刻(T5)的HR、SBP、DBP、MAP、心排血量指数(cardiac output index,CI)和每搏指数(stroke volume index,SVI).记录术中麻黄碱用量. 结果 观察组患者麻醉期间麻黄素用量明显低于对照组[(1.5±3.2)mg比(6.4±8.6) mg] (P＜0.05),观察组患者T3、T4和T5时的心脏SVI明显高于T0[分别为(35±8)、(36±9)、(36±9) ml/m2比(31±8)ml/m2](P＜0.05). 结论 老年患者硬膜外局部麻醉药物中添加少量去氧肾上腺素可减少硬膜外麻醉后麻黄素的用量,并可以增加心脏SVI.     

Pulse Pressure Variation is a Valuable Marker for Predicting Fluid Responsiveness in Brain-Dead Donors

PurposeHemodynamic management in brain-dead donors (BDDs) is challenging due to hemodynamic instabilities. We compared functional parameters with traditional parameters for hemodynamic monitoring in BDDs.Materials and methodsSeventeen BDDs with a positive balance of >500 mL for 8 hours were included. Functional hemodynamic monitoring, including pulse pressure variation (PPV), stroke volume variation (SVV), cardiac output, and systemic vascular resistance index (SVRI) was performed in the setting of tidal volume of 6 mL/kg to 8 mL/kg and minimal positive end-expiratory pressure of 5 cm to 8 cm H2O. Responders were defined by a cardiac output increase of >15% after fluid therapy.ResultsAmong the 17 BDDs (mean age, 46.80±13.91 years), 15 were male. Seven responders out of 17 (41.1%) had a significantly higher PPV (22.8±8.4 vs 13.4±5.9%, P = .038) and serum albumin level (3.2±0.6 vs 2.6±0.5 g/L, P = .040) at baseline than nonresponders. However, other hemodynamic markers such as SVV and SVRI were similar between groups. Traditional markers of volume status, such as heart rate, central venous pressure, hemoglobin, and serum uric acid level were also similar between the 2 groups. Hemodynamic markers including PPV, SVV, and SVRI were significantly reduced in responders.ConclusionsPPV was the most valuable hemodynamic marker for predicting volume responsiveness in BDDs.     

肺叶切除术患者不同通气模式下每搏量变异度的变化

目的 探讨肺叶切除术患者不同通气模式下每搏量变异度(SW)的变化.方法 择期行肺叶切除术患者44例,年龄44～64岁,体重47～86 kg,ASA分级Ⅰ或Ⅱ级.采用FloTrac压力换能器及Vigileo心输出量监测仪持续监测CI、每搏量指数(SVI)和SVV.术中补液速率6～8 ml·kg-1·h-1(晶胶比1∶1)维持血容量.于仰卧位双肺通气5 min(T1)、侧卧位双肺通气2 min(T2)、单肺通气开胸前(T3)、单肺通气开胸后5 min(T4)、30 min(T5)、单肺通气+PEEP5 cm H2O 1 min(T6)、15 min(T7)、肺复张前(T8)、肺复张即刻(T9)和肺复张后1 min(T10)时记录SVV、CI和SVI.SVV＜ 13％为正常值.结果 患者术中血液动力学平稳,CI和SⅥ均在正常范围内波动.T9时SVV＞13％,其余各时间点均＜13％.SVV T2,3之间差异无统计学意义,T5～7之间差异均无统计学意义(P＞0.05);T9时SVV较T8.10时升高(P＜0.01).结论 肺叶切除术中,单肺通气以及单肺通气联合PEEP 5 cm H2O时SVV可用于指导液体治疗的判断,而在肺复张时SVV不能指导液体治疗.     

两种浓度丙泊酚用于腹腔镜胆囊切除术患者药物效应比较

目的 比较相同剂量1％丙泊酚与2％丙泊酚用于腹腔镜胆囊切除术患者的药物效应及达到相同药物效应时的药物用量.方法 选择拟行腹腔镜胆囊切除术患者100例,采用随机数字表法分为两组(每组50例):输注1％丙泊酚组(Ⅰ组)、输注2％丙泊酚组(Ⅱ组).诱导剂量均为2 mg/kg,整个麻醉过程中用Narcotrend麻醉深度监护仪监测麻醉深度,诱导完成后根据Narcotrend指数调整两组丙泊酚的泵速.观察患者Narcotrend指数下降到36的时间、意识消失时间、监测诱导开始15 min内MAP和HR下降百分比、丙泊酚第1小时用量及停药至Narcotrend指数恢复到65的时间.结果 两组患者意识消失时间及Narcotrend指数下降到36的时间Ⅰ组分别为(115±45)s和(136±54)s,Ⅱ组分别为(156±60)s和(183±61)s,Ⅰ组短于Ⅱ组(P＜0.05).丙？白酚使用总量和丙泊酚第1小时用量Ⅰ组分别为(41±15)ml和(36±10) ml,Ⅱ组的2倍用药量分别为(53±18) ml和(46±15)ml,Ⅱ组的2倍用药量大于Ⅰ组用药量(P＜0.05).结论 2％丙泊酚麻醉药用量的2倍大于1％丙泊酚,而不是等量的,这说明1％丙泊酚的药效可能强于2％丙泊酚,2％丙泊酚经济效益相对较低.     

Prediction of fluid responsiveness in patients during cardiac surgery

Background. Left ventricular stroke volume variation (SVV) hasbeen shown to be a predictor of fluid responsiveness in varioussubsets of patients. However, the accuracy and reliability ofSVV are unproven in patients ventilated with low tidal volumes. Methods. Fourteen patients were studied immediately after coronaryartery bypass grafting (CABG). All patients were mechanicallyventilated in pressure-controlled mode [tidal volume 7.5 (1.2)ml kg^–1]. In addition to standard haemodynamic monitoring,SVV was assessed by arterial pulse contour analysis. Left ventricularend-diastolic area index (LVEDAI) was determined by transoesophagealechocardiography. A transpulmonary thermodilution techniquewas used for measurement of cardiac index (CI), stroke volumeindex (SVI) and intrathoracic blood volume index (ITBI). Allvariables were assessed before and after a volume shift inducedby tilting the patients from the anti-Trendelenburg (30°head up) to the Trendelenburg position (30° head down). Results. After the change in the Trendelenburg position, SVVdecreased significantly, while CI, SVI, ITBI, LVEDAI, centralvenous pressure (CVP) and pulmonary artery occlusion pressure(PAOP) increased significantly. Changes in SVI were significantlycorrelated to changes in SVV (r=0.70; P<0.0001) and to changesin LVEDAI, ITBI, CVP and PAOP. Only prechallenge values of SVVwere predictive of changes in SVI after change from the anti-Trendelenburgto the Trendelenburg position. Conclusions. In patients after CABG surgery who were ventilatedwith low tidal volumes, SVV enabled prediction of fluid responsivenessand assessment of the haemodynamic effects of volume loading.