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     

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。     

目标导向液体治疗在高危患者手术中的应用

背景 现代麻醉在保障手术患者术中良好的镇静、镇痛、肌松、抑制应激反应的同时,更多关注患者围手术期多脏器功能的保护.特别在处理有明显的病理生理异常的患者时,麻醉医生需要监测更多心血管系统参数,使用液体和血管活性药使心脏前负荷、后负荷、血管张力达到最优水平,满足重要脏器的灌注. 目的 主要介绍目标指导液体治疗(goal-directed therapy,GDT)在高危手术患者的应用. 内容 GDT是指通过使用液体和血管活性药使心脏前负荷、后负荷、血管张力达到最优水平,时时保证冠状动脉灌注压.介绍GDT的研究背景、依据及如何在高危患者手术应用. 趋向 GDT为临床医生处理危重症患者提供了更有效、更标准的方法,它的应用前景更加光明.     

脉搏指示连续心排血量技术在心脏前负荷测量的应用近况

监测心脏负荷变化对了解心脏功能具有十分重要的临床意义。中心静脉压(CVP)与右心前负荷虽存在一定关系,但不能完全反映左心前负荷。经动脉插管入左心房及肺动脉漂浮导管(Swan-Ganz导管)测量肺小动脉嵌顿压(PCWP)评估左心前负荷的方法,虽能为判断心脏前负荷提供较为可靠的依据,     

左心充盈不足但中心静脉压增高一例

在临床上,中心静脉压(CVP)通常用于监测前负荷,指导容量治疗。血管张力及顺应性、右室功能及顺应性、胸腔压力、三尖瓣功能失常都可以影响 CVP,在上述因素稳定的情况下,CVP 与心脏指数(CI)有紧密的正相关性,而当上述影响因素出现异常时,CVP 就会出现异常,容易导致误诊误治。本院收治1例报道如下。患者,男,19岁,体重58 kg,身高165 cm,幼年因心脏杂     

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,     

血管外肺水和肺血管通透性的监测与临床应用

血管外肺水和肺血管通透性作为反映肺病理生理的指标,其测定的方法经不断的改进,从最初的离体动物实验到现在比较成熟的PICCO法.血管外肺水和胸腔内血容量比中心静脉压和肺小动脉楔压更能反映心脏前负荷的状况,血管外肺水和肺血管通透性可以反映肺损伤的程度,并对危重病患者的监测和治疗有较大的指导意义.随着PICCO技术的逐渐推广,今后两者在临床上的应用会更加广泛,在今后的研究上,如何降低血管外肺水和肺血管高通透性,减轻肺损伤,用何种方法或药物降是今后研究的方向.     

鱼精蛋白拮抗肝素140例分析

激活全血凝固时间(ACT)用来指导和监测体外循环中的肝素抗凝和拮抗,目前在心脏手术中较广泛地应用。现将我院140例病人在ACT监测下使用鱼精蛋白(以下简称PRTM)拮抗肝素情况报告如下。临床资料本组选择体外循环(CPB)心脏手术140例,其中男75例,女65例,年龄5-65岁,体重13-80kg。随机将病例分为两组,一组     

正性肌力药和血管扩张药的临床选用现状

影响心排血量的易变因素有五种即:心率和心律、心肌收缩力、心室前负荷和后负荷,根据对上述因素的不同作用可选择出特异性增强心脏功能的药物。为在临床上有效地应用正性肌力药和血管扩张药,需了解药物的量-效关系、用药途径及用药速率,还应考虑药物的相互作用及病人本身的病理生理状况。只有对所选择药物的心脏及血流动力效应有一系统认识,才能对严重心脏病人安全而有效地使用正性肌力药和血管扩张药。     

脉搏指示连续心排血量技术在肝移植围术期的应用

目的 评价脉搏指示连续心排血量(PiCCO)技术在肝移植术中的应用价值.方法 25例行原位肝移植术的终末期肝病患者,ASA Ⅲ或Ⅳ级.记录术中PiCCO监测数据,并与Swan-Ganz漂浮导管血流动力学监测结果比较.结果 与切皮前比较,无肝前期各项监测指标无显著变化,无肝期全心舒张末期容积指数(GEDI)、胸腔内血容积指数(ITBI)、每搏输出量指数(SVI)和心脏指数(CI)均显著降低(P<0.01),每搏输出量变异(SVV)和脉压变异(PPV)较大(P<0.01),新肝期CI显著增加(P<0.01),肺血管通透性指数(PVPI)增加(P<0.05).通过温度稀释法共测得数据200组.其中,PiCCO所测得的CI(PCI)与导管法显示的CI相关良好(r=0.84,P<0.01).结论 PiCCO技术能较准确的反映心脏前负荷以及肺血管通透性的变化.     

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.     

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.     

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 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.     

The impact of intra-aortic balloon pumping on cardiac output determination by pulmonary arterial and transpulmonary thermodilution in pigs

OBJECTIVE: The aim of this study was to evaluate the impact of intra-aortic balloon pumping (IABP) on the comparison of simultaneous measurements of cardiac output via pulmonary arterial and transpulmonary thermodilution (PiCCO; Pulsion Medical Systems, Munich, Germany). DESIGN: Prospective. SETTINGS: University research laboratory. PARTICIPANTS: The data were derived from 9 anesthetized (fentanyl, propofol, flunitrazepam, rocuronium) and ventilated pigs. INTERVENTIONS: A thermodilution catheter was inserted into the pulmonary artery, a PiCCO catheter into the abdominal aorta through the right femoral artery, epicardial atrial pacing wires through a thoracotomy, and a balloon catheter for counterpulsation into the descending thoracic aorta through the left femoral artery. Cardiac output was varied over a wide range by cardiac pacing between 80 and 150/min in steps of 10/min and was measured without and during IABP at an assist frequency of 1:1. MEASUREMENTS AND MAIN RESULTS: A total of 236 paired cardiac output measurements were carried out in a range of cardiac output between 1.4 to 4.9 L/min. A close correlation was found between transpulmonary and pulmonary arterial thermodilution both without and during IABP (r = 0.94 and 0.93, respectively) and a good agreement of both methods (bias of 0.30 and 0.26 L/min, respectively; precision 0.47 and 0.52 L/min, respectively). CONCLUSIONS: Transpulmonary thermodilution is suitable for cardiac output measurement during IABP. Hence, in critically ill patients with cardiac pump failure, blood flow may be determined as accurately with the less-invasive transpulmonary method as with the traditional pulmonary arterial thermodilution one.     

Volumetric monitoring: principles of application

The transpulmonary thermodilution indicator (TPID) technique has been recently introduced and diffuse in clinical practice. This "less-invasive" device measures intermittent cardiac output and, based on pulse contour method, continuous cardiac output, that agree with cardiac output obtained with pulmonary artery catheter in different clinical setting. Moreover it allowed stroke volume variation and pulse pressure variation experimental and clinically validate fluid responsiveness index in controlled mechanically ventilated patients. The TPID technique allowed an estimations of preload index such as intrathoracic blood volume and "lung edema" index as extra vascular lung water. We reviewed the principle of clinical application based on the current literature now available from this device. Cardiac output monitoring based on TPID technique is safe and accurate, as well as fluid responsiveness indicator (SVV and PPV). Intrathoracic blood volume seems to be a good preload index but the results reported in literature are not homogeneous in all its applications. Extra vascular lung water index is a very interesting parameter particularly in critically ill setting but its clinical application is not yet widely documented.     

Assessment of fluid responsiveness in mechanically ventilated cardiac surgical patients

BACKGROUND AND OBJECTIVE: Accurate assessment of preload responsiveness is an important goal of the clinician to avoid deleterious volume replacement associated with increased morbidity and mortality in mechanically ventilated patients. This study was designed to evaluate the accuracy of simultaneously assessed stroke volume variation and pulse pressure variation using an improved algorithm for pulse contour analysis (PiCCO plus, V 5.2.2), compared to the respiratory changes in transoesophageal echo-derived aortic blood velocity (deltaVpeak), intrathoracic blood volume index, central venous pressure and pulmonary capillary wedge pressure to predict the response of stroke volume index to volume replacement in normoventilated cardiac surgical patients. METHODS: We studied 20 patients undergoing elective coronary artery bypass grafting. After induction of anaesthesia, haemodynamic measurements were performed before and after volume replacement by infusion of 6% hydroxyethyl starch 200/0.5 (7 mL kg(-1) ) with a rate of 1 mL kg(-1) min(-1). RESULTS: Baseline stroke volume variation correlated significantly with changes in stroke volume index (deltaSVI) (r2 = 0.66; P < 0.05) as did baseline pulse pressure variation (r2 = 0.65; P < 0.05), whereas baseline values of deltaVpeak, intrathoracic blood volume index, central venous pressure and pulmonary artery wedge pressure showed no correlation to deltaSVI. Pulse contour analysis underestimated the volume-induced increase in cardiac index measured by transpulmonary thermodilution (P < 0.05). CONCLUSIONS: The results of our study suggest that stroke volume variation and its surrogate pulse pressure variation derived from pulse contour analysis using an improved algorithm can serve as indicators of fluid responsiveness in normoventilated cardiac surgical patients. Whenever changes in systemic vascular resistance are expected, the PiCCO plus system should be recalibrated.     

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.