每搏输出量变异度和胸腔内血容量指数预测感染性休克机械通气患者容量反应性的价值比较

目的比较每搏输出量变异度(SVV)和胸腔内血容量指数(ITBVI)预测感染性休克机械通气患者容量反应性的临床价值。方法 60例行机械通气治疗的感染性休克患者根据液体复苏前后心排指数变化率(ΔCI)分为有反应组(32例,ΔCI≥15%)和无反应组(28例,ΔCI15%)。比较两组患者液体复苏前后SVV、CVP、心率(heart rate, HR)、CI、MAP、ITBVI等血流动力学相关指标水平,分析液体复苏前SVV、ITBVI与ΔCI的相关性关系,并对SVV、ITBVI预测容量反应性予以ROC分析。结果有反应组患者液体复苏治疗期间液体总量与无反应组比较差异无统计学意义(P0.05),有反应组患者液体复苏前心率明显快于无反应组(P0.05),SVV、CI、ITBVI均明显低于无反应组(P0.05),两组患者液体复苏后各项指标比较差异无统计学意义(P0.05);ITBVI与ΔCI呈负相关性关系(r=-0.447,P=0.032),SVV与ΔCI呈正相关性关系(r=0.771,P=0.007),SVV与ΔCI的相关性比ITBVI与ΔCI的相关性更明显;SVV、ITBVI预测感染性休克机械通气患者容量反应性均具有统计学意义(P0.05),但SVV的AUC、灵敏度、特异度及P值均好于ITBVI。结论 SVV和ITBVI在容量反应性预测方面均具有较好的临床价值,但SVV与ITBVI比较有更高的灵敏度和特异度,更适宜应用于感染性休克机械通气患者的容量反应性预测。     

超声联合小剂量容量负荷试验对感染性休克患者容量反应性的评估价值

目的:观察超声联合小剂量容量负荷试验对评估感染性休克患者容量反应性的价值。方法:选取行机械通气及丙泊酚镇静的感染性休克患者64例,按照常规剂量容量负荷试验结果分组,其中研究组(容量反应组) 32例,500 m L晶体液快速输注后,心输出量增加率(△CO 500)≥15%,对照组(容量无反应组) 32例,△CO 500 15%。比较分析2组小剂量容量负荷试验前、后的心率(HR)、中心静脉压(CVP)、平均动脉压(MAP)、心脏指数(CI)、心输出量(CO)、主动脉速度时间-积分(VTI)等指标。结果:容量负荷试验前,2组患者HR、CVP、MAP、CI、CO、VTI等指标无显著差异(均P0. 05),容量负荷试验后,研究组的HR、CVP、MAP、CI、CO、VTI等指标与试验前比较,差异有统计学意义(均P 0. 05)。结论:超声联合小剂量容量负荷试验能对感染性休克患者容量反应性作出良好评估,具有较高临床应用价值。     

急性心肌梗死心源性休克常用前负荷评估指标准确性的探讨

目的对比研究利用脉搏指示持续心输出量监测仪(PiCCO)获得的容量负荷指标胸腔内血容量指数(ITB-VI)及全心舒张末期容量指数(GEDVI)能否较中心静脉压(CVP)及肺动脉楔压(PAOP)更准确地评估急性心肌梗死心源性休克患者的前负荷状态。方法 8例急性心肌梗死心源性休克患者气管插管呼吸机支持,设置潮气量8ml/kg、呼气末正压(PEEP)5～8cmH2O,充分镇痛镇静。留置Swan-Ganz、PiCCO导管,监测血流动力学,PAOP>20mmHg纳入试验,每6小时为一研究周期,PAOP下降、血流动力学无明显恶化者,再次监测血流动力学,对结果进行统计分析。结果①SVI与CVP、PA0P负相关,r分别为-0.46和-0.49(P<0.05);SVI与GEDVI、ITBVI的r分别为0.35和0.37,P>0.05,相关性不显著;②CVP及PA0P的变化率较GEDVI及ITBVI的变化率大(F为19.26,P<0.01,差异有统计学意义)。结论 PiCCO容量负荷指标ITBVI及GEDVI用于评估急性心肌梗死心源性休克患者的前负荷状态有一定缺陷,而压力负荷指标CVP及PAOP的准确性、敏感性较高。     

每搏量变异评价顽固性感染性休克患者容量反应性

目的 评价每搏量变异(SVV)能否作为机械通气的顽固性感染性休克患者容量反应性指标.方法 对收治于北京协和医院加强医疗科的42例顽固性感染性休克患者进行容量负荷试验,比较容量负荷试验有反应者和无反应者间SVV的差异,通过受试者工作特征(ROC)曲线确定SVV判断容量反应性的阈值.结果 (1)42例患者中24例患者容量负荷试验有反应,18例患者无反应.(2)容量负荷试验前有反应者和无反应者间中心静脉压、心率、平均动脉压、全心舒张末容积指数差异无统计学意义,有反应者和无反应者间SVV差异有统计学意义(17.7±7.1比9.6±4.1,P=0.006).(3)以SVV≥12%评价顽固性感染性休克患者容量反应性,灵敏度为77%,特异度为85%.结论 SVV可作为顽固性感染性休克患者容量反应性指标.     

呼气末二氧化碳分压的变化对感染性休克机械通气患者容量反应性的预测价值

目的 探讨呼气末二氧化碳分压(PETCO2)在被动抬腿试验中的变化及对感染性休克机械通气患者容量反应性的预测价值.方法 选择行机械通气治疗的感染性休克患者42例.分别在被动抬腿试验、容量负荷试验后采用脉搏指示连续心输出量(PiCCO)监测患者血流动力学变化,呼气末二氧化碳监测装置监测患者PETCO2.以接受者操作特征曲线(ROC曲线)分析被动抬腿试验后PETCO2的变化对容量反应性的预测价值.结果 (1)42例患者中,24例有容量反应性(有反应组),18例无反应(无反应组).有反应组患者被动抬腿试验后心指数(CI)增加(21.4±12.9)％,PETCO2增加(9.6±4.7)％;无反应组CI[(3.2±1.1) L·min-1·m-1]和PETCO2[(33±4) mm Hg(1 mm Hg =0.133 kPa)]较基线值无变化[(3.0±1.0)L· min-1·m-1;(32±4) mm Hg;P值均＞0.05].有反应组患者被动抬腿试验后CI和PETCO2的变化均高于无反应组[(21.4±12.9)％比(6.4±3.5)％,(9.6±4.7)％比(3.0±2.6)％;P值均＜0.05].(2)相关分析:被动抬腿试验后CI的变化与PETCO2的变化呈正相关(r=0.64,P＜0.05).(3)被动抬腿试验后PETCO2的变化预测容量反应性的ROC曲线下面积为0.900±0.056(95％ CI0.775 ～1.000),以5％为临界值,敏感性为88.0％,特异性88.2％.结论 被动抬腿试验后PETCO2的变化可以作为预测感染性休克机械通气患者容量反应性的无创、简便的指标.     

被动抬腿试验联合中心静脉压预测老年脓毒症患者的容量反应性

目的探讨应用被动抬腿试验(PLR)联合中心静脉压(CVP)预测老年脓毒症患者的容量反应性。方法选择老年脓毒症患者94例,根据容量负荷试验后每搏量的增加值分为有反应组(41例)和无反应组(53例),均进行PLR联合CVP评估,主要监测心率(HR)、平均动脉压(MAP)、每搏量(SV)、心输出量(CO)、氧合指数(PO_2/FiO_2,P/F)。结果有反应组患者扩容后HR为(91.56±9.65)次/min,低于无反应组扩容后〔(97.26±9.71)次/min,P0.05〕;有反应组患者扩容后MAP、SV、CO和P/F分别为(57.29±1.94)mm Hg、(56.93±2.39)ml、(8.06±0.63)L/min和(220.41±19.4),均高于无反应组〔(55.34±2.08)mm Hg、(53.17±2.18)ml、(7.19±0.65)L/min和(215.37±18.25),P0.05〕;有反应组患者扩容后CVP和ΔCVP分别为(7.88±0.79)mm H_2O和(23.58±1.93)%,均低于无反应组扩容后〔(6.25±0.68)mm H_2O和(20.24±1.72)%,P0.05〕。结论应用PLR联合CVP可预测老年脓毒症患者容量反应性,有反应组患者CO明显增加,CVP降低。     

血管外肺水指数和胸腔内血容积指数在感染性休克合并ARDS患者液体管理中的指导意义

目的探讨血管外肺水指数(EVLWI)和胸腔内血容积指数(ITBVI)在感染性休克合并急性呼吸窘迫综合征(ARDS)患者液体管理中的指导意义。方法选择吉林省人民医院重症医学科2012年6月至2013年12月收治的56例感染性休克合并ARDS患者,随机分为两组。EVLWI+ITBVI组30例,以脉搏指示连续心排出量(Pi CCO)技术测定EVLWI和ITBVI,联合CVP指导液体治疗;对照组26例,以中心静脉压(CVP)指导液体管理。比较两组患者在(EGDT)的达标后,治疗1、3 d的SOFA评分、去甲肾上腺素用量、最高血清乳酸、呼吸参数(呼气末正压水平、呼吸频率、顺应性、氧合指数)、24 h液体正平衡、血肌酐、机械通气时间、住ICU时间及28 d病死率。结果 EVLWI+ITBVI组3 d时SOFA评分、去甲肾上腺素用量、血乳酸、呼吸参数、24 h液体正平衡均较1 d明显下降,而对照组无显著变化;EVLWI+ITBVI组3 d时血肌酐无明显增加,而对照组明显增加(P<0.05)。EVLWI+ITBVI组机械通气时间、住ICU时间和28 d病死率均较对照组明显减少(P<0.05)。结论与单纯CVP指导的液体管理相比,ITBVI+EVLWI可以更精确评估感染性休克合并ARDS患者的容量状态,更合理地指导液体治疗,减少机械通气时间和住ICU时间,降低病死率。     

左室流出道血流速率时间积分预测老年感染性休克患者容量反应性的应用价值

目的研究左室流出道血流速率时间积分(VTI)预测老年感染性休克患者容量反应性的临床价值。方法选取2018年1～12月在院诊治的老年感染性休克患者110例作为研究对象。使用床边超声测量患者的VTI、每搏量(SV)和心输出量(CO),对患者进行容量负荷试验。根据容量负荷试验(即补液试验)后患者SV或CO增加程度分为有反应(R)组(57例)和无反应(NR)组(53例),其中R组增加程度不小于15%,NR组增加程度在15%以下。比较两组VTI、SV和CO;采用受试者工作特征(ROC)曲线分析VTI对老年感染性休克患者容量反应性的预测价值。结果 NR组患者VTI、SV、CO在T0、T100、T500比较差异无统计学意义(P0.05)。R组在T500时的VTI[(22.38±3.68)cm]明显高于T0、T100[(16.72±3.13)cm、(20.62±3.51)cm];R组在T500时的SV[(74.06±10.2)ml]明显高于T0、T100[(55.71±6.42)ml、(59.58±20.62)ml];R组在T500时的CO[(7.34±1.12)L/min]明显高于T0、T100[(5.28±0.98)L/min、(6.16±0.94)L/min],三个时间点比较差异有统计学意义(P0.05)。采用ROC评估分析,ΔVTI100预测容量反应性的特异度为0.959,敏感度为0.927,预测容量反应的临界值为15.5%;ΔVTI100预测容量反应性的ROC曲线下面积为0.96±0.03(P=0.001)。结论对于老年感染性休克患者,VTI能够更好地预测患者的容量反应性。     

左西孟旦和米力农对射血分数减低型心力衰竭患者血流动力学参数影响的比较

目的 比较左西孟旦和米力农对射血分数降低型心力衰竭（HFrEF）急性发作时患者血流动力学相关参数的影响。 方法 选取新疆维吾尔自治区人民医院心内科监护室2017年10月 ~ 2018年11月入住的HFrEF患者122例,随机分为左西孟旦组（66例）和米力农组（56例）,在常规心衰指南用药的基础上,使用左西孟旦或米力农的同时采用脉搏指数连续心排出量（Pulse index continuous cardiac output,PICCO）监测在不同时段监测患者心指数（CI）、胸腔内血容量指数（ITBVI）、全心舒张末期容量指数（GEDVI）、血管外肺水指数（EVLWI）等血流动力学参数进行比较分析。 结果 左西孟旦组和米力农组在年龄、性别、左室射血分数（LVEF）等均衡性检验无统计学差异;在左西孟旦组和米力农组之间0（h）时CI、GEDVI、ITBVI、EVLWI比较均无统计学差异,左西孟旦组CI、GEDVI、ITBVI、EVLWI在0（h）、3（h）、8（h）、24（h）之间两两比较差异具有统计学意义（P < 0.01）,米力农组0（h）CI与ITBVI除在0（h）与3（h）两结果相比无统计学意义,CI、GEDVI、ITBVI、EVLWI结果在其余各时间段两两对比均具有统计学意义（P < 0.01）;左西孟旦组和米力农组CI、EVLEI在0（h）与3（h）、8（h）、24（h）时差异均无统计学意义,ITBVI、GEDVI除0 h差异无统计学意义外,其余各时间点差异均有统计学意义（P < 0.05,P < 0.01）。 结论 左西孟旦组与米力农组均可改善血流动力学,不同时间段其改善效果不同,通过PICCO监测可有效评估血流动力学指标变化情况并协助评估临床治疗决策。     

超声预测感染性休克患者容量反应性的临床研究

目的 :探讨超声在预测重症监护病房(ICU)感染性休克患者容量反应性中的临床应用价值。方法 :对2015-01至2015-04我院ICU收治的42例进行机械通气的感染性休克患者进行容量负荷试验,试验前后均采用超声测量下腔静脉呼吸变异率(ΔIVC)、主动脉峰值流速呼吸变异率(ΔVpeak_(AO))、肱动脉最大速度变异率(ΔVpeak_(BA))以及每搏量增加值(ΔSV),并记录临床各项指标。根据对试验的反应将患者分为有反应组和无反应组,比较两组上述指标的差异及各参数与ΔSV的相关性,用受试者工作特征曲线(ROC曲线)评价试验前各项指标预测容量反应性的临床价值。结果 :42例患者进行容量负荷试验47次,有反应组25例次,无反应组22例次。试验前,有反应组ΔIVC、ΔVpeak_(AO)以及ΔVpeak_(BA)的值均高于无反应组;ΔIVC、ΔVpeak_(AO)以及ΔVpeak_(BA)与ΔSV显著相关(r分别为0.631、0.668、0.619);ΔIVC、ΔVpeak_(AO)以及ΔVpeak_(BA)曲线下面积分别为0.817、0.853、0.866,且均有较高的特异度和敏感度。结论 :应用超声测定的血流动力学参数能够对ICU机械通气感染性休克患者液体治疗时的容量反应性进行预测,指导其液体治疗。     

Hemodynamic monitoring by double-indicator dilution technique in patients after orthotopic heart transplantation

STUDY OBJECTIVES: A transpulmonary thermal-dye dilution (TDD) technique using cold indocyanine green dye was utilized to monitor cardiac index (CI) and preload in patients after heart transplantation. Preload, determined by intrathoracic blood volume index (ITBVI) and global end-diastolic volume index (GEDVI), was compared to central venous pressure (CVP) and pulmonary artery occlusion pressure (PAOP) and was correlated with stroke volume index (SVI). DESIGN: Prospective study. SETTING: Cardiac surgery ICU at a university hospital. PATIENTS: Forty patients (34 men, 6 women) with a mean (+/- SD) age of 54.4+/-8.5 years after orthotopic heart transplantation. Measurements and results: CI and preload measurements were performed with TDD and pulmonary artery catheters in the ICU at 3, 6, 12, 24, 36, 48, and 72 h postoperatively. The femoral artery CI was compared with the pulmonary artery CI. Changes in the ITBVI, GEDVI, CVP, and PAOP were correlated with changes in the SVI. No difference was found between the femoral and pulmonary arterial CIs (r = 0.98 [bias, 0.35 L/min/m(2)]; p<0.01). There was no statistically significant correlation between changes in the SVI and changes in CVP (r = -0.23,) and PAOP (r = -0.06). However, the ITBVI (r = 0.65; p<0.01) and the GEDVI (r = 0.73; p<0.01) were significantly correlated to changes in the SVI. Changes in the same direction occurred between the SVI and the GEDVI as well as between the SVI and the ITBVI in 76.3% and 71.9% of patients, respectively, while CVP and PAOP also changed in the same direction as SVI in only 35.1% and 36.9% of patients, respectively. CONCLUSION: ITBVI and GEDVI are more reliable preload parameters than CVP and PAOP. Even in denervated hearts, ITBVI and GEDVI show significant correlations with SVI. The transpulmonary indicator dilution technique is promising and should be investigated further.     

Does central venous pressure predict fluid responsiveness? A systematic review of the literature and the tale of seven mares

BACKGROUND: Central venous pressure (CVP) is used almost universally to guide fluid therapy in hospitalized patients. Both historical and recent data suggest that this approach may be flawed. OBJECTIVE: A systematic review of the literature to determine the following: (1) the relationship between CVP and blood volume, (2) the ability of CVP to predict fluid responsiveness, and (3) the ability of the change in CVP (DeltaCVP) to predict fluid responsiveness. DATA SOURCES: MEDLINE, Embase, Cochrane Register of Controlled Trials, and citation review of relevant primary and review articles. Study selection: Reported clinical trials that evaluated either the relationship between CVP and blood volume or reported the associated between CVP/DeltaCVP and the change in stroke volume/cardiac index following a fluid challenge. From 213 articles screened, 24 studies met our inclusion criteria and were included for data extraction. The studies included human adult subjects, healthy control subjects, and ICU and operating room patients. DATA EXTRACTION: Data were abstracted on study design, study size, study setting, patient population, correlation coefficient between CVP and blood volume, correlation coefficient (or receive operator characteristic [ROC]) between CVP/DeltaCVP and change in stroke index/cardiac index, percentage of patients who responded to a fluid challenge, and baseline CVP of the fluid responders and nonresponders. Metaanalytic techniques were used to pool data. DATA SYNTHESIS: The 24 studies included 803 patients; 5 studies compared CVP with measured circulating blood volume, while 19 studies determined the relationship between CVP/DeltaCVP and change in cardiac performance following a fluid challenge. The pooled correlation coefficient between CVP and measured blood volume was 0.16 (95% confidence interval [CI], 0.03 to 0.28). Overall, 56+/-16% of the patients included in this review responded to a fluid challenge. The pooled correlation coefficient between baseline CVP and change in stroke index/cardiac index was 0.18 (95% CI, 0.08 to 0.28). The pooled area under the ROC curve was 0.56 (95% CI, 0.51 to 0.61). The pooled correlation between DeltaCVP and change in stroke index/cardiac index was 0.11 (95% CI, 0.015 to 0.21). Baseline CVP was 8.7+/-2.32 mm Hg [mean+/-SD] in the responders as compared to 9.7+/-2.2 mm Hg in nonresponders (not significant). CONCLUSIONS: This systematic review demonstrated a very poor relationship between CVP and blood volume as well as the inability of CVP/DeltaCVP to predict the hemodynamic response to a fluid challenge. CVP should not be used to make clinical decisions regarding fluid management.     

Global end-diastolic volume as an indicator of cardiac preload in patients with septic shock

STUDY OBJECTIVE: To assess the value of the global end-diastolic volume (GEDV) evaluated by transpulmonary thermodilution as an indicator of cardiac preload. DESIGN: Prospective clinical study. SETTING: Medical ICU of a university hospital (20 beds). PATIENTS: Thirty-six patients with septic shock. INTERVENTIONS: Volume loading and dobutamine infusion. MEASUREMENTS AND RESULTS: Hemodynamic parameters were evaluated in triplicate by the transpulmonary thermodilution technique: (1) before and after 66 fluid challenges in 27 patients, and (2) before and after 28 increases in dobutamine infusion rate in 9 patients. Volume loading induced a significant (p < 0.001) increase in central venous pressure (CVP) from 10 +/- 4 to 13 +/- 4 mm Hg, in GEDV index from 711 +/- 164 to 769 +/- 144 mL/m(2), in stroke volume index (SVI) from 36 +/- 12 to 42 +/- 12 mL/m(2), and in cardiac index (CI) from 3.4 +/- 1.1 to 3.9 +/- 1.2 L/min/m(2) (mean +/- SD). Changes in GEDV index were correlated (r = 0.72, p < 0.001) with changes in SVI, while changes in CVP were not. The increase in SVI was > 15% in 32 of 66 instances (positive response). The preinfusion GEDV index was lower (637 +/- 134 mL/m(2) vs 781 +/- 161 mL/m(2), p < 0.001) in the cases of positive response, and was negatively correlated with the percentage increase in GEDV index (r = - 0.65, p < 0.001) and in SVI (r = - 0.5, p < 0.001). Dobutamine infusion induced an increase in SVI (32 +/- 11 mL/m(2) vs 35 +/- 12 mL/m(2), p < 0.05) and in CI (2.8 +/- 0.6 L/min/m(2) vs 3.2 +/- 0.6 L/min/m(2), p < 0.001) but no significant change in CVP (13 +/- 3 mm Hg vs 13 +/- 3 mm Hg) and in GEDV index (823 +/- 221 mL/m(2) vs 817 +/- 202 mL/m(2)). CONCLUSION: In patients with septic shock, our findings demonstrate that, in contrast to CVP, the transpulmonary thermodilution GEDV index behaves as an indicator of cardiac preload.     

Stroke volume and pulse pressure variation for prediction of fluid responsiveness in patients undergoing off-pump coronary artery bypass grafting

STUDY OBJECTIVES: Stroke volume variation (SVV) and pulse pressure variation (PPV) determined by the PiCCOplus system (Pulsion Medical Systems; Munich, Germany) may be useful dynamic variables in guiding fluid therapy in patients receiving mechanical ventilation. However, with respect to the prediction of volume responsiveness, conflicting results for SVV have been published in cardiac surgery patients. The goal of this study was to reevaluate SVV in predicting volume responsiveness and to compare it with PPV. DESIGN: Prospective nonrandomized clinical investigation. SETTING: University-based cardiac surgery. PATIENTS: Forty patients with preserved left ventricular function undergoing elective off-pump coronary artery bypass grafting. INTERVENTIONS: Volume replacement therapy before surgery. MEASUREMENTS AND RESULTS: Following induction of anesthesia, before and after volume replacement (6% hydroxyethyl starch solution, 10 mL/kg ideal body weight), hemodynamic measurements of stroke volume index (SVI), SVV, PPV, global end-diastolic volume index (GEDVI), central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) were obtained. Also, left ventricular end-diastolic area index (LVEDAI) was assessed by transesophageal echocardiography. Prediction of ventricular performance was tested by calculating the area under the receiver operating characteristic (ROC) curves and by linear regression analysis; p < 0.05 was considered significant. All measured hemodynamic variables except heart rate changed significantly after fluid loading. GEDVI, CVP, PCWP, and LVEDAI increased, whereas SVV and PPV decreased. The best area under the ROC curve (AUC) was found for SVV (AUC = 0.823) and PPV (AUC = 0.808); the AUC for other preload indexes ranged from 0.493 to 0.636. A significant correlation with changes of SVI was observed for SVV (r = 0.606, p < 0.001) and PPV (r = 0.612, p < 0.001) only. SVV and PPV were closely related (r = 0.861, p < 0.001). CONCLUSIONS: In contrast to standard preload indexes, SVV and PPV, comparably, showed a good performance in predicting fluid responsiveness in patients before off-pump coronary artery bypass grafting.     

Goal-directed therapy of cardiac preload in induced whole-body hyperthermia

OBJECTIVES: To optimize volume therapy during induced whole-body hyperthermia (WBH) < or = 42.2 degrees C, pulmonary capillary wedge pressure (PCWP) and intrathoracic blood volume index (ITBVI) were compared as goal parameters. DESIGN: Prospective clinical study. SETTING: ICU at university hospital. PATIENTS: Twenty-three patients with metastatic cancers. INTERVENTIONS: Radiant WBH in combination with induced hyperglycemia, hyperoxemia, and chemotherapy was applied. Volume therapy was directed to the PCWP (group A, 8 to 12 mm Hg [20 treatments]), or to ITBVI (group B, 800 to 1,100 mL/m2 [19 treatments]) following a standardized protocol. Goals other than PCWP and ITBVI were cardiac index of > 3.5 L/min/m2 and mean arterial pressure of > 55 mm Hg. MEASUREMENTS AND RESULTS: In addition to the primary goals PCWP and ITBVI, at defined temperatures, central venous pressure (CVP), extravascular lung water index, the number of infusions, and packed RBCs, as well as serum lactate level, norepinephrine dosage, and levels of liver enzymes, bilirubin, creatinine, and urea were measured. Patients in group A received a significantly greater mean (+/- SD) amount of crystalloids compared to those in group B (6,175 +/- 656 vs 3,947 +/- 375 mL, respectively) and required significantly lower dosages of vasoconstrictors compared with patients in group B. Except for the lower values of CVP in patients in group A during hyperthermia, all of the other hemodynamic and laboratory parameters showed no significant differences between the groups or stayed in a normal range. CONCLUSION: PCWP and ITBVI are useful parameters to assess preload in induced WBH. Differences in crystalloids and vasopressor dosages may suggest an appropriate ITBVI of > 1,100 mL/m2 for patients with good cardiopulmonary health under such extremely hypercirculatory conditions.     

Comparison of initial distribution volume of glucose and intrathoracic blood volume during hemodynamically unstable States early after esophagectomy

STUDY OBJECTIVE: We have reported that initial distribution volume of glucose (IDVG) measures the central extracellular fluid volume in the presence of fluid gain or loss without apparent modification of glucose metabolism. We hypothesized that IDVG has a close relationship with intrathoracic blood volume (ITBV). We examined whether IDVG can correlate with ITBV during hemodynamically unstable states early after esophagectomy. DESIGN: Prospective clinical study. SETTING: General ICU. PATIENTS OR PARTICIPANTS: Twelve consecutive hypotensive patients who required volume loading during the first 10 postoperative hours after admission to the ICU. INTERVENTIONS: Indexed ITBV (ITBVI) and cardiac index (CI) were measured by single transpulmonary thermodilution technique using 10 mL of cold saline solution. Indexed IDVG (IDVGI) was then determined by the administration of 5 g of glucose and calculated by applying a one-compartment model. Three sets of measurements were performed: immediately after admission to the ICU, during hypotension, and after subsequent volume loading. MEASUREMENTS AND RESULTS: When hypotension developed, stroke volume index (SVI), central venous pressure, and ITBVI were decreased but IDVGI and CI were not. All these variables were increased after volume loading. IDVGI was correlated only slightly with either ITBVI (r2 = 0.23) or SVI (r2 = 0.38) but moderately with CI (r2 = 0.61). CONCLUSIONS: Results does not support that IDVGI can be equivalently used as an alternative measure of ITBVI or SVI, but IDVG may be clinically relevant as a measure of the fluid volume affecting CI even during hemodynamically unstable states after esophagectomy.     

Respiratory changes in aortic blood velocity as an indicator of fluid responsiveness in ventilated patients with septic shock

STUDY OBJECTIVE: To investigate whether the respiratory changes in peak velocity (Vpeak) of aortic blood flow could be related to the effects of volume expansion on cardiac index. DESIGN: Prospective clinical study. SETTING: Medical ICUs of a university hospital (20 beds) and of a nonuniversity hospital (15 beds). PATIENTS: Nineteen sedated septic shock patients who were receiving mechanical ventilation and who had preserved left ventricular (LV) systolic function. INTERVENTION: Volume expansion. MEASUREMENTS AND RESULTS: Analysis of aortic blood flow by transesophageal echocardiography allowed beat-to-beat measurement of Vpeak before and after volume expansion. Maximum values of Vpeak (Vpeakmax) and minimum values of Vpeak (Vpeakmin) were determined over one respiratory cycle. The respiratory changes in Vpeak (Delta Vpeak) were calculated as the difference between Vpeakmax and Vpeakmin divided by the mean of the two values and were expressed as a percentage. The indexed LV end-diastolic area (EDAI) and cardiac index were obtained at the end of the expiratory period. The volume expansion-induced increase in cardiac index was > or = 15% in 10 patients (responders) and < 15% in 9 patients (nonresponders). Before volume expansion, Delta Vpeak was higher in responders than in nonresponders (20 +/- 6% vs 10 +/- 3%; p < 0.01), while EDAI was not significantly different between the two groups (9.7 +/- 3.7 vs 9.7 +/- 2.4 cm(2)/m(2)). Before volume expansion, a Delta Vpeak threshold value of 12% allowed discrimination between responders and nonresponders with a sensitivity of 100% and a specificity of 89%. Volume expansion-induced changes in cardiac index closely correlated with the Delta Vpeak before volume expansion (r(2) = 0.83; p < 0.001). CONCLUSION: Analysis of respiratory changes in aortic blood velocity is an accurate method for predicting the hemodynamic effects of volume expansion in septic shock patients receiving mechanical ventilation who have preserved LV systolic function.     

Pulse pressure variation predicts fluid responsiveness following coronary artery bypass surgery

STUDY OBJECTIVE: To determine whether the degree of pulse pressure variation (PPV) and systolic pressure variation (SPV) predict an increase in cardiac output (CO) in response to volume challenge in postoperative patients who have undergone coronary artery bypass grafting (CABG), and to determine whether PPV is superior to SPV in this setting. DESIGN AND SETTING: This was a prospective clinical study conducted in the cardiovascular ICU of a university hospital. PATIENTS: Twenty-one patients were studied immediately after arrival in the ICU following CABG. INTERVENTION: A fluid bolus was administered to all patients. MEASUREMENTS: Hemodynamic measurements, including central venous pressure (CVP), pulmonary artery occlusion pressure (PAOP), CO (thermodilution), percentage of SPV (%SPV), and percentage of PPV (%PPV), were performed shortly after patient arrival in the ICU. Patients were given a rapid 500-mL fluid challenge, after which hemodynamic measurements were repeated. Patients whose CO increased by >/= 12% were considered to be fluid responders. The ability of different parameters to distinguish between responders and nonresponders was compared. RESULTS: In response to the volume challenge, 6 patients were responders and 15 were nonresponders. Baseline CVP and PAOP were no different between these two groups. In contrast, the %SPV and the %PPV were significantly higher in responders than in nonresponders. Receiver operating characteristic curve analysis suggested that the %PPV was the best predictor of fluid responsiveness. The ideal %PPV threshold for distinguishing responders from nonresponders was found to be 11. A PPV value of >/= 11% predicted an increase in CO with 100% sensitivity and 93% specificity. CONCLUSION: PPV and SPV can be used to predict whether or not volume expansion will increase CO in postoperative CABG patients. PPV was superior to SPV at predicting fluid responsiveness. Both of these measures were far superior to CVP and PAOP.