心脏前负荷测量进展

心脏前负荷在临床应用有重要的指导价值,但监测方法各有利弊,单一温度稀释法PicCCo技术具有广阔的应用前景,较Swan-Ganz导管技术更敏感,可较准确监测心脏前负荷的变化,为指导临床诊断和治疗提供可靠的依据。因临床上受多种因素所影响,PiCCO所测得的胸腔内血容积等参数作为反映心脏前负荷的指标,仍需进行更深入的分析与探讨。目前在临床上还不能忽视传统技术的应用。     

食管超声多普勒监测指导非体外循环冠脉搭桥术病人容量治疗的可行性

非体外循环(CPB)冠脉搭桥术(OPCAB)中,进行大血管操作时常发生血液动力学的波动。动物实验表明增加心脏的前负荷可以减轻心脏移位时血液动力学的变化,而对于临床上如何在OPCAB中维持适当前负荷尚需进一步研究。食管超声多普勒监测仪可以根据降主动脉血流波形,实时监测心排血量的变化,并反映心脏前负荷的水平。本研究拟探讨食管超声多普勒监测指导OPCAB病人容量治疗的可行性。     

对胸腔内血容量作为心脏前负荷的评价

心脏前负荷监测在临床治疗中具有重要指导意义,以压力代容量的传统指标中心静脉压(CVP)、肺动脉楔压(PCWP)监测均具有一定局限性。近年来脉搏指示剂心排血量(pulse contour cardiac output,PiCCO)技术应用,为前负荷监测提供更多信息,其中胸腔内血容量(intrathoracicblood volum     

左心导管测量心排血量的实验研究

目的介绍一种新型经左心使用温度稀释法测量心排血量(CO)的导管和方法。方法健康杂种犬8只,采用自身对照,经右心使用肺动脉气囊漂浮导管,经动脉使用自制的左心测定管。其放置部位分前端在左心室内和在主动脉根部两种情况。在控制呼吸、停呼吸、控制性降压中、控制性降压后5min同时测量CO和心脏指数(CI)。结果在四个时点经左右心两种导管所测值之间差异无统计学意义,且肺动脉导管与左心导管在两种情况下测得CO呈正相关(γ为0.986和0.989),CI也呈正相关(γ为0.983和0.985);左心导管两种情况下所测CO与CI之间也显著相关(γ为0.992和0.988)。结论新型左心测定管所测CO与肺动脉气囊漂浮导管所测值之间有良好相关性,且设计简单,操作方便。     

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心力衰竭是指心脏无力泵出足够的血流量 ,以满足周围组织代谢的需求 ,导致血流动力学异常与神经激素系统激活。心力衰竭的主要症状取决于两种病理生理现象即静脉淤血与心排量降低。心力衰竭与手术死亡率密切相关 ,心功能Ⅰ级者手术死亡率为 4% ,Ⅱ级者为 1 1 % ,Ⅲ级者为2 5 % ,Ⅳ级者为 6 7%。处理好围手术期的心力衰竭 ,至关重要。心力衰竭按发展的速度分为急性与慢性。1　急性左心衰竭起病急 ,以肺水肿为主要表现。1 1　诱发急性左心衰竭常见原因(1 )前负荷下降为低血容量。 (2 )前负荷短期内增加输液速度太快或输液量太多。 (3)后负荷…     

急性高容量血液稀释联合硬膜外阻滞用于患者手术的临床观察

急性高容量血液稀释(AHH)是围手术期一种血液保护的有效措施,但在实施过程中,不同程度地存在心脏前负荷加重的问题,尤其对老年患者,因心脏储备功能及对循环血量改变的适应能力下降,临床上常规实施AHH存有顾虑。本研究在联合应用硬膜外阻滞(EA)的同时,利用其引起区域性血管扩张,     

Swan—Ganz气囊飘浮导管测压法

中心静脉压(CVP)在危重病人用于判断心脏前负荷是一大进展,但它只能反映右心室充盈情况,不能及早反映肺动脉压的变化和直接反映左心情况。当心源性休克时,左心室泵功能衰竭,首先升高的是左室舒张末期压(LVEDP)、左房压(LAP),其次是肺动脉压(PAP)和肺毛细血管楔压(PCWP),最后是右房压(RAP)和CVP。此时CVP升高可能已发展到充血性     

血管扩张药在急性心衰中的应用

急性心衰的病因众多,但其机制不外三种—循环容积减少,心输出量减少和外周血管阻力降低。在某些病例中,补充血容量和应用正性肌力性药物以增多心输出量(CO)就足以纠正其生理紊乱;另一种病例的特征是 CO 减少,左室充盈压(LVFP)及总外周阻力(TPR)均增高,对这种病例宜用血管扩张药治疗。在正常心脏,左心前负荷在左心决定心输出量方面,比后负荷更为重要;但若心力一旦衰竭 CO 就主要决定于血流的阻力。急性     

左心辅助装置与麻醉

左心辅助装置已经成为心脏手术后心脏功能不全、心脏移植前的临时支持以及晚期心力衰竭的有效治疗方法。对左心辅助装置的作用、适应证、种类、麻醉处理的进展作一综述。     

心脏手术中心静脉穿刺异常一例

中心静脉穿刺置管是心脏手术等大手术和重症监测的重要操作，通过它监测中心静脉压，麻醉医师可以获取有关患者心脏前负荷、心功能等的信息，而且它是快速补液及给药的重要通路。但中心静脉穿刺时可出现并发症，如误伤动脉引发血肿，穿透胸膜引起血气胸等；同时也会出现一些位置异常的假象。因此，在操作时根据血液颜色、压力等征象和辅助检查正确判断假象是由解剖异常引起的还是由于穿刺引起的，对判断导管位置正确与否，及全面了解病人病情有非常重要的意义。     

Assessment of intrathoracic blood volume as an indicator of cardiac preload: single transpulmonary thermodilution technique versus assessment of pressure preload parameters derived from a pulmonary artery catheter.

OBJECTIVE: To analyze the clinical value of a new device (PiCCO) for cardiac output measurement and volume preload parameter assessment, based on transpulmonary thermodilution technique, as an alternative to the pulmonary artery thermodilution technique and assessment of pressure preload parameters derived from the pulmonary artery catheter. DESIGN: Prospective, controlled, clinical study. SETTING: University hospital. PARTICIPANTS: Eighteen patients with ejection fraction >50% undergoing coronary artery bypass graft surgery. INTERVENTIONS: A baseline measurement was performed after induction of anesthesia under clinical steady-state conditions (T1). Hypovolemia, defined as central venous pressure (CVP) <10 mmHg and pulmonary capillary wedge pressure (PCWP) <12 mmHg, was treated by infusion of 6% hydroxyethyl starch 200/0.5 (7 mL/kg). After 10 minutes, a second measurement (T2) was performed. MEASUREMENTS AND MAIN RESULTS: The mean difference (bias) between transpulmonary thermodilution cardiac output and pulmonary artery thermodilution cardiac output did not differ at the 2 sample points. Changes in pressure preload parameters of the pulmonary artery catheter (CVP, PCWP) did not correlate with changes in cardiac output or stroke volume, whereas changes in volume preload parameter intrathoracic blood volume (ITBV) of the PiCCO correlated significantly with changes in cardiac output and stroke volume (r = 0.55, p < 0.05; r = 0.62, p < 0.01). CONCLUSION: These results suggest that increased cardiac preload is more reliably reflected by ITBV than by CVP or PCWP. The assessment of ITBV by the transpulmonary single indicator dilution technique is an interesting alternative to the pressure preload parameters.     

Hemodynamics during liver transplantation

Assessing the optimal volemia in the perioperative course of liver transplantation is a challenge for the anesthesiologist. Traditional estimates of intravascular volume status, such as pulmonary artery occlusion pressure (PAOP), have been widely shown to poorly correlate with changes in cardiac output among critically ill patients. Hence, there has been recent interest in alternative, catheter-related, bedside device volume estimates using thermodilution. Continuous end diastolic volume (CEDVI) showed better correlations with cardiac performance than cardiac filling pressures in studies performed in critically ill patients. When compared with conventional pressure-derived data, preload monitoring estimated as intrathoracic blood volume index (ITBVI) with the PiCCO system based on an integrated transpulmonary thermodilution technique better reflected left ventricular filling both in critically ill patients and those who underwent liver transplantation. Moreover, in liver transplantation, the use of transoesophageal echocardiography (TEE) has been increasing for it provides rapid visualization of the dimension and function of heart chambers as well as the left ventricular end diastolic area index (EDAI) that seem to correlate with graded acute hypovolemia, although its validity as on preload index is still under discussion.     

Volumetric assessment of left heart preload by thermodilution: comparing the PiCCO-VoLEF system with transoesophageal echocardiography

The new Volumetric Ejection Fraction monitoring system (VoLEF), when combined with the Pulse Contour Cardiac Output monitoring system (PiCCO) system, allows measurement of left and right heart end-diastolic volumes by thermodilution. The aim of this study was to evaluate whether the left heart end-diastolic volume index determined by the VoLEF system (LHEDI) better reflects left ventricular end-diastolic area index (LVEDAI) measured by transoesophageal echocardiography than does global end-diastolic volume index (GEDI) measured by the PiCCO system alone. Following induction of anaesthesia, PiCCO, VoLEF and transoesophageal echocardiography measurements were performed before and after a fluid challenge in 20 patients scheduled for elective cardiac surgery. Both left ventricular end-diastolic area index and global end-diastolic volume index, but not left heart end-diastolic volume index, significantly increased after fluid administration. Mean bias +/- 2 SD for DeltaLHEDI-DeltaLVEDAI was -2.2 +/- 32.0% and for DeltaGEDI-DeltaLVEDAI -0.6 +/- 16.8%. In contrast to global end-diastolic volume index, the use of left heart end-diastolic volume index determined by the VoLEF system cannot be recommended as an estimate of left ventricular preload.     

Pulmonary artery thermodilution cardiac output vs. transpulmonary thermodilution cardiac output in two patients with intrathoracic pathology

In two adult patients, one with a severe hemorrhage and one with a partial anomalous pulmonary vein, cardiac output (CO) measurements were performed simultaneously by means of the bolus transpulmonary thermodilution technique (COao) and continuous pulmonary artery thermodilution method (CCOpa). In both cases, the methods revealed clinically significant different cardiac output values based upon the site of measurement and the underlying pathology. The assessment of cardiac output (CO) is considered an important part of cardiovascular monitoring of the critically ill patient. Cardiac output is most commonly determined intermittently by the bolus thermodilution technique with a pulmonary artery catheter (COpa). As continuous monitoring of CO is preferable to this intermittent technique, two major techniques have been proposed. Firstly, a nearly continuous thermodilution method (CCOpa) using a heating filament mounted on a pulmonary artery catheter (Baxter Edwards Laboratories, Irvine, CA), with a clinically acceptable accuracy compared with the intermittent bolus technique. Based on these results we assumed CCOpa equivalent to real CO during hemodynamically stable conditions, and secondly, a continuous cardiac output system based on pulse contour analysis (PCCO), such as the PiCCO system (Pulsion Medical System, Munchen, Germany). To calibrate this device, which uses a derivation of the algorithm of Wesseling and colleagues, an independently obtained value of CO by the transpulmonary thermodilution method (COao) is used. Clinical validation studies in patients without underlying intrathoracic pathology, comparing transpulmonary COao with the pulmonary technique (COpa), mostly yielded good agreement.     

Volumetric preload measurement by thermodilution: a comparison with transoesophageal echocardiography

Background. End-diastolic volume indices determined by transpulmonarythermodilution and pulmonary artery thermodilution may givea better estimate of left ventricular preload than pulmonarycapillary wedge pressure monitoring. The aim of this study wasto compare volume preload monitoring using the two differentthermodilution techniques with left ventricular preload assessmentby transoesophageal echocardiography (TOE). Methods. Twenty patients undergoing elective cardiac surgerywith preserved left–right ventricular function were studiedafter induction of anaesthesia. Conventional haemodynamic variables,global end-diastolic volume index using the pulse contour cardiacoutput (PiCCO) system (GEDVI_PiCCO), continuous end-diastolicvolume index (CEDVI_PAC) measured by a modified pulmonary arterycatheter (PAC), left ventricular end-diastolic area index (LVEDAI)using TOE and stroke volume indices (SVI) were recorded beforeand 20 and 40 min after fluid replacement therapy. Analysisof variance (Bonferroni–Dunn), Bland–Altman analysisand linear regression were performed. Results. GEDVI_PiCCO, CEDVI_PAC, LVEDAI and SVI_PiCCO/PAC increasedsignificantly after fluid load (P<0.05). An increase >10%for GEDVI_PiCCO and LVEDAI was observed in 85% and 90% of thepatients compared with 45% for CEDVI_PAC. Mean bias (2 SD) betweenpercentage changes (     

Preload index: pulmonary artery occlusion pressure versus intrathoracic blood volume monitoring during lung transplantation

In this study, during lung transplantation, we analyzed a conventional preload index, the pulmonary artery occlusion pressure (PAOP), and a new preload index, the intrathoracic blood volume index (ITBVI), derived from the single-indicator transpulmonary dilution technique (PiCCO System), with respect to stroke volume index (SVIpa). We also evaluated the relationships between changes (Delta) in ITBVI and PAOP and DeltaSVIpa during lung transplantation. The reproducibility and precision of all cardiac index measurements obtained with the transpulmonary single-indicator dilution technique (CIart) and with the pulmonary artery thermodilution technique (CIpa) were also determined. Measurements were made in 50 patients monitored with a pulmonary artery catheter and with a PiCCO System at six stages throughout the study. Changes in the variables were calculated by subtracting the first from the second measurement (Delta(1)) and so on (Delta(1) to Delta(5)). The linear correlation between ITBVI and SVIpa was significant (r(2)=0.41; P < 0.0001), whereas PAOP poorly correlated with SVIpa (r(2) = -0.01). Changes in ITBVI correlated with changes in SVIpa (Delta(1), r(2) = 0.30; Delta(2), r(2) = 0.57; Delta(4), r(2) = 0.26; and Delta(5), r(2) = 0.67), whereas PAOP failed. The mean bias between CIart and CIpa was 0.15 l. min(-1). m(-2) (1.37). In conclusion, ITBVI is a valid indicator of cardiac preload and may be superior to PAOP in patients undergoing lung transplantation. IMPLICATIONS: The assessment of intrathoracic blood volume index (ITBVI) by the transpulmonary single-indicator technique is a useful tool in lung transplant patients, providing a valid index of cardiac preload that may be superior to pulmonary artery occlusion pressure. However, more prospective, randomized studies are necessary to evaluate the role and limitations of this technique.     

Perioperative pulse contour cardiac output analysis in a patient with severe cardiac dysfunction

We describe a patient with severe left ventricular dysfunction simultaneously monitored with pulse contour cardiac output (PiCCO) analysis, a continuous cardiac output pulmonary artery catheter (continuous COPAC) and intraoperative transoesophageal echocardiography (TOE). There was good agreement between cardiac output (CO) measurements obtained by the three techniques prior to cardiopulmonary bypass (CPB). Agreement of CO measurements following CPB was initially pool; but improved following recalibration of PiCCO. PiCCO-derived global end-diastolic volume index (GEDVI) and cardiac function index (CFI), were assessed as markers of left ventricular preload and myocardial contractility, respectively. GEDVI correlated well with CO in the postoperative period. CFI increased more than two-fold following coronary revascularization and milrinone administration, and there was also a temporal relationship between the CFI and the dose of milrinone in the first 24 hours of treatment. Global end-diastolic volume and cardiac function index may be useful additional measures of left ventricular preload and myocardial contractility in patients with severe left ventricular dysfunction.     

Measurement of cardiac output by transpulmonary arterial thermodilution using a long radial artery catheter. A comparison with intermittent pulmonary artery thermodilution

Cardiac output can be measured accurately by transpulmonary arterial thermodilution using the PiCCO (Pulsion Medical Systems, Munich, Germany) system with a femoral artery catheter. We have investigated the accuracy of a new 50 cm 4 French gauge radial artery catheter and the ability to use the system with a shorter radial catheter. We studied 18 patients who had undergone coronary artery surgery and made three simultaneous measurements of cardiac output by arterial thermodilution and with a pulmonary artery catheter. The radial catheter was withdrawn in 5 cm increments and the measurements were repeated. We found close agreement between arterial thermodilution and pulmonary artery thermodilution with a mean (SD) bias of 0.38 (0.77) l x min(-1). Arterial thermodilution became unreliable once the catheter had been withdrawn by more than 5 cm. We conclude that cardiac output measurement with arterial thermodilution with a radial catheter is interchangeable with that derived from a pulmonary artery catheter, and that a centrally sited arterial catheter is required for accurate determination of cardiac output by transpulmonary arterial thermodilution.     

Haemodynamic monitoring and liver function evaluation by pulsion cold system Z-201 (PCS) during orthotopic liver transplantation

Pulsion cold system (PCS, COLD) is a haemodynamic monitoring system that allows measurement of cardiac output (CO), partial blood volumes, lung water, and liver function. The aim of the study was to evaluate this monitoring system during human orthotopic liver transplantation (OLT) for the following: (a) to determine agreement between CO measurements via pulmonary artery thermodilution (CO TDpa), and aortic transpulmonary thermodilution (CO TDa); (b) to compare the preload dates obtained with the COLD with central venous pressure (CVP) and pulmonary capillary wedge (PCWP); and (c) to assess the use of the plasma disappearance rate (PDR) of indocyanine green (ICG) as a measure of graft function. Fifteen consecutive patients undergoing OLT were studied. Each patient received a pulmonary artery catheter and a 5F aortic catheter with an integrated thermistor. The thermistor of the aortic catheter were connected to one computer system (COLD-Z201, Pulsion Medical Systems, Munich, Germany). Haemodynamic data were registered an all the phases of OLT. PDR was measured during surgery in 12 patients. Correlations between PDR and the other markers of graft function (transaminases, protrombine time, and bile production) were sought. The correlation coefficient between CO TDa (COLD) and CO TDpa was r = 0.766 (p < 0.001), and an additional analysis according to Bland-Altman was also performed. There was a better correlation between the cardiac index (determined by two monitoring systems) and the volume measurements than the correlation observed with pressure preload parameters. The best correlations were found between the cardiac index in the femoral artery and intrathoracic blood volume index (ITBVI) and pulmonary blood volume index (PBVI) (r = 0.79 and r = 0.72, respectively; p < 0.01). PDR measured in the group patients with bad early graft function were lower (13.6 +/- 2.7) than those in the group with a good graft function (21.6 +/- 9) (p < 0.05). The degree of discrepancy between femoral and pulmonary thermodilution cardiac output measures is very wide during OLT so as to make the techniques using the COLD machine clinically useless. On the other hand, the volumes measured by COLD, specially ITBVI and PBVI, are more useful to asses the pre-load than pressure measurements. In OLT, the PDR measured within the first few hours after liver reperfusion may become a useful tool for early diagnosis of primary graft dysfunction (PDF).