B型利钠肽结合血流动力学监测对呼吸困难的诊断价值

目的 探讨急诊室快速血B型利钠肽(BNP)检测并同时进行无创血流动力学监测对呼吸困难患者病因诊断的临床意义.方法 选择2007年5月至2008年1月354例因呼吸困难就诊患者,使用无创超声心排量监测仪进行心输出量(CO)测定,同时测定血BNP浓度,以是否为心源性呼吸困难进行分组,分别对CO以及BNP心源性呼吸困难的诊断情况进行统计.结果 确诊127例心源性呼吸困难患者,检测CO以及BNP具有负相关性(r=-0.645,P=0.000);在确诊227例非心源性呼吸困难组,CO及BNP两者阴性检出人数差异具有统计学意义(102例比11例,P=0.000),CO和BNP无相关性.结论 急诊室呼吸困难患者血浆BNP浓度判定心源性呼吸困难具有局限性,应用无创超声心排量监测仪监测CO血流动力学对鉴别呼吸困难具有临床应用价值.     

Bioz.com数字化无创血流动力学监测系统在合贝爽治疗高血压急症中的应用

目的评价Bioz.com数字化无创血流动力学监测系统在合贝爽治疗高血压急症中的应用价值。方法对34例高血压急症患者用合贝爽10~20mg溶于生理盐水50m1中,初始剂量为3~10μg.kg-1·min-1,维持泵入24h.给药前及给药后10、30、60、120min用Bioz.com数字化无创血流动力学监测系统记录血流动力学数据:收缩压、舒张压、心率、心排出量(CO)、体血管阻力、加速指数(ACI)。结果合贝爽治疗各种病因所致的高血压急症均有显著效果,血压、心率、体血管阻力在用药后10,30,60,120min逐渐下降,分别同用药前比较均有显著性差异(P<0.05),而CO,ACI用药后无变化(P>0.05)。结论Bioz.com数字化无创血流动力学监测系统使用方便,能及时反映患者用药过程中的病情变化,具有较强的实用价值。     

部分二氧化碳复吸入法心排出量监测的原理及应用

介绍部分二氧化碳复吸入法无创心排出量监测的原理以及临床应用的研究进展。该法基于 Fick原理 ,操作简便 ,价格相对较低 ,无需特殊的技术操作 ,与有创监测相关性好 ,且可避免有创监测带来的并发症 ,是一种值得推广的监测手段。     

无创心输出量监测在危重病监护中的应用

目的 探讨电阻抗无创心输出量监测在危重病患者中的应用。方法 选择2001-02～2003-09ICU收治的38例患者用电阻抗无创心输出量监测系统与多谱勒心脏超声,同时测定38例患者心输出量,并对结果进行对比分析。结果 两种方法的测定值有显著的相关性(r=0.908)。结论 电阻抗元创心输出量监测与多谱勒心脏超声测定结果是一致的,它不仅能准确地测定心输出量,而且还具有无创、连续、简便、价廉的优点。     

无创心排出量监测在危重病患者中的应用价值

目的：探讨无创心排出量（C0）监测在危重病患者中的应用价值。方法：选择本院呼吸与重症医学科（RICU）收治的危重病人共255例,对其进行无创CO监测,同时行心脏彩超检查,及脉搏指示连续心排血量技术（PiCC0）检查,比较三种方法所得的c0监测情况。结果：无创CO监测、心脏彩超检查、PiCCO检查测得到CO平均值分别是（5．07±2．14）L／min、（4．91±2．08）L／min、（5．14±2．16）L／min,经方差分析,三者差异非常显著（P〈0．01）。对三种检测方法进行两两之间比较发现,与心脏彩超检查相比,无创心排出量监测、PiCCO检测的CO值显著升高（P〈0．05,P〈0．01）,而无创心排出量监测与PiCCO检测的CO值无显著差异（P〉0．05）。结论：无创心排出量监测与脉搏指示连续心排血量技术监测心排出量值分别优于心脏彩超检查（P〈0．05,〈0．01）,且二者无显著差异,建议广泛应用于临床。     

无创心功能监测在冠状动脉旁路移植术后监护中的应用

目的探讨无创心功能监测在冠状动脉旁路移植术后监护中的应用。方法选择2006年1-3月心外ICU收治的29例冠状动脉旁路移植术患者，应用胸腔生物阻抗法心脏血流动力仪和Swan-Ganz导管，同时测定患者的心排出量和肺动脉楔压，并对结果进行对比分析。结果两种方法测三的结果心排出量（CO）分别为（5．03±1．48）L／min和（5．25±1．55）L／min（P〉0．05），r=0．82（P〈0．001）；肺动脉楔压（PCWP）的结果分别为（10．35±2．18）mmHg和（9．86±2．67）mmHg（P〉0．05），r=0．71（P〈0．05）。两种方法测定的结果具有良好的相关性。结论胸腔生物阻抗法无创心功能监测与Swan—Ganz导管测定结果是一致的，它不仅能准确地测定心排出量和肺动脉楔压，而且还具有无创、连续、简便和廉价的优点。     

食管超声监测心排血量在冠状动脉旁路手术中的应用

目的观察冠状动脉旁路手术(CABG)中使用食管超声(TEE)进行心排量(CO)测定的可行性及准确性,评价心排量在术中的应用。方法28例CABG患者全身麻醉后,经食管置入TEE探头至胃底,取主动脉瓣环水平,用彩色多普勒测量血流速度,由计算机计算心排量。同期置入S-G导管用热稀释法测定心排量。将两者进行比较。结果术中使用TEE进行心排量的无创监测操作简单,与漂浮导管热稀释法测定值相关性好(P<0.01)。结论在CABG术中,利用TEE连续监测心排量具有不影响手术、无创和连续的优点,结合HR、MAP等指标能及时了解血液动力学的变化,以利于围术期心脏功能的处理。     

FloTrac/Vigileo系统用于冠状动脉搭桥术中血流动力学监测

目的:观察FloTrac/Vigileo系统在非体外循环冠状动脉旁路移植术(OPCABG)血流动力学监测中应用的可行性,分析其与肺动脉导管(PAC)心排量监测(CCO)结果的相关性。方法:随机选择50例择期OPCABG的患者,所有患者同时应用连续心排出量(APCO)和CCO进行心排量(CO)监测,分别在切皮前、吻合左冠状动前降支、吻合回旋支、吻合后降支、关胸后5个时间点,测定2种方法监测的CO、心排指数(CI)及其他血流动力学参数。结果:术中在固定器放置、改变心脏位置、血管活性药物及使用正性肌力药情况下,APCO监测结果均有所改变,变化趋势与PAC监测结果一致。2种监测方法在各时间点监测的CO值的相关系数(r)分别为0.70,0.59,0.78,0.74及0.85,各时间点CI差值的偏倚范围分别为:(0.39±0.06)L.min-1.m-2、(0.48±0.12)L.min-1.m-2、(0.26±0.06)L.min-1.m-2、(0.27±0.06)L.min-1.m-2及(0.30±0.05)L.min-1.m-2,提示2种方法监测结果有较好的相关性。2种监测方法所得(SVR)在吻合血管时变化趋势与各自监测所得CO变化趋势相反。结论:APCO用于OP-CABG术中连续CO监测具有可行性,与PAC监测法所得CO结果相关,监测结果体现了较好的即时性和动态性。     

心力衰竭患者血浆脑利钠肽水平与无创血流动力学监测的相关性

目的 探讨心力衰竭患者血脑利钠肽(BNP)水平与运用无创血流动力学监测的关系.方法 应用无创血流动力学检测仪测定71例心力衰竭患者的各项指标,同时测定他们的BNP水平,并对BNP水平与无创血流动力学监测的各项指标进行相关分析.结果 BNP水平与外周血管阻力(SVR)(R=0.710,P<0.01)、外周血管阻力指数(S...     

间歇热稀释法与间接Fick法测定肺动脉高压患者心排出量结果的比较

目的:比较间歇热稀释法与间接Fick法测定肺动脉高压患者心排出量结果的一致性.方法:79例患者,男性18例,女性61例,平均年龄(36±10)岁.其中特发性肺动脉高压41例,先天性心脏病相关性肺动脉高压12例,结缔组织病相关性肺动脉高压12例,慢性血栓栓塞性肺动脉高压5例,其他肺动脉高压9例.上述患者同时采用间歇热稀释法与间接Fick法测定心排出量,对两种方法的测定结果进行了相关分析及Bland-Altman一致性分析.然后根据间接Fick法测定结果将患者分为低心排出量组和正常心排出量组,并重新进行上述相关分析及一致性分析.结果:间歇热稀释法心排出量3.60±1.16(1.88～7.05)L/min,间接Fick法心排出量3.56±1.12(1.90～6.88)L/min,差值(间歇热稀释法-间接Fick法)为(0.04±0.70)L/min;两种方法心排出量相关分析得r=0.81(P<0.01).低心排出量组(n=23,心排出量≤3 L/min):间歇热稀释法心排出量2.76±0.65(1.9～4.5)L/min,间接Fick法心排出量2.46±0.26(1.9～3.0)L/min,差值为(0.3±0.59)L/min;两种方法心排出量相关分析得r=0.45(P<0.01).正常心排出量组(n=56,心排出量>3 L/min):间歇热稀释法心排出量3.95±1.15(2.23～7.05)L/min,间接Fick法心排出量4.01±1.01(3.01～6.88)L/min;差值为(-0.07±0.73)L/min;两种方法心排出量相关分析得r=0.78(P<0.01).结论:间歇热稀释法与间接Fick法测定肺动脉高压患者的心排出量一致性欠佳.两种方法测定结果不能互换.     

Non-invasive measurement of cardiac output by the CO2 rebreathing method and its reliability in clinical practice

A Commercially available, non-invasive system for estimation of cardiac output by the CO2-rebreathing method (Sensormedicus MMC4400) was evaluated to determine its reliability in clinical practice. Values of cardiac output were obtained at rest and during mild to moderate bicycle ergometer work in patients with ischemic heart disease or hypertension. Cardiac output measured by the CO2-rebreathing method was significantly correlated with that measured simultaneously by dye dilution or thermodilution methods. Cardiac output values determined by the CO2-rebreathing method were the same as those obtained by the two invasive methods in reproducibility. When cardiac output and Vo2 were normalized for body weight, they were significantly correlated with each other. This result was obtained both by the CO2-rebreathing method, and by the two invasive methods. These results indicate that MMC4400 will provide a value for cardiac output substantially the same as that obtained by using more laborious invasive methods. Clinical use of the CO2-rebreathing method has been limited by technical difficulties. However, the recently developed non-invasive cardiac output measurement system (MMC4400) uses a microcomputer to analyze the results, and the operator can determine the values for cardiac output easily. Furthermore, it simultaneously measures VO2, VCO2 and VE, so the operator can estimate the measured values for cardiac output with background information on ventilatory gas analysis. Determination of cardiac output through the use of the CO2-rebreathing method is suitable particularly for exercise studies, and it is expected to be a useful device, in the near future, for evaluating cardiac function of patients with primary cardiac diseases.     

Dynamics of parameters of diastole and subendocardial right ventricular blood flow in adult patients after correction of atrial septal defect

The study of intracardiac hemodynamics and subendocardial blood flow in 55 adults with atrial septal defect confirmed practical value of assessment of myocardial contractility by long term catheterization of right cardiac chambers, construction of right ventricular function curves and "pressure-volume" diagrams. Simultaneous graphical registration with the help of computer diagnostic system represented character and direction of changes of controlled parameters during the period of observation as well as peculiarities of interventricular interaction after removal of isotonic right ventricular overload. Compared with traditional hemodynamic monitoring this approach to analysis of intracardiac hemodynamics provided real time assessment of cardiac function, facilitated elucidation of causes of cardiac output lowering and optimization of myocardial contractility regulation.     

Assessment of right ventricular function in patients with congenital heart defects with pulmonary hypertension. The role of some parameters of hemodynamics

Intracardiac hemodynamics was studied in 46 patients with intraventricular septal defect and 32 patients with incomplete atrioventricular canal. The study confirmed practical value of assessment of contractility of right ventricular myocardium basing on information obtained during prolonged catheterization of the right cardiac chambers, construction of right ventricular function curves and analysis of pressure-volume loops. Compared with conventional hemodynamic monitoring this approach to analysis of intracardiac hemodynamics provided real time assessment of cardiac function, facilitated elucidation of causes of lowering of cardiac output and elaboration of optimal pathways of regulation of the myocardial contractile state.     

Reevaluation of the role of atrial systole to cardiac hemodynamics: Evidence for pulmonary venous regurgitation during abnormal atrioventricular sequencing

Twenty open-chest dogs with experimental AV heart block were evaluated hemodynamically, angiographically, and by M-mode echocardiography to further elucidate mechanisms whereby abnormal AV sequencing results in decreased cardiac hemodynamics. During fixed-rate AV pacing, there was a consistent decrease in cardiac output, left ventricular and aortic pressures, and left ventricular dimensions with an increase in left atrial pressure as the AV interval was decreased from 100 to 0 msec, and there were further changes when the AV interval was set at ?50 and ?100 msec. The hemodynamic consequences of atrial fibrillation with regular ventricular rhythms were similar to the effects of an AV interval of 0 msec. It is important to note that retrograde blood flow into the pulmonary venous system (pulmonary venous regurgitation) was demonstrated by left atrial angiography at AV intervals of both ?50 and ?100 msec. However, left ventricular angiography failed to reveal mitral regurgitation during fixed-rate pacing at any AV interval or during atrial fibrillation with regular ventricular rates. Thus, during tachyarrhythmias characterized by abnormal AV sequencing, not only is there the loss of active atrial contribution to ventricular filling but there is also evidence for a retrograde or “negative atrial kick” further compromising cardiac hemodynamics.     

Long-term recording of cardiac output via an implantable haemodynamic monitoring device

Long-term monitoring of central haemodynamics with implantedmonitoring systems might be valuable in managing heart failurepatients. Such systems offer an opportunity for repeated ‘semi-invasive’cardiac output determinations according to the Fick principle. Five patients, four with chronic heart failure and one withchronic pulmonary disease, underwent supine exercise testingduring cardiac catheterization at 0, 2, 6 and 11 months afterimplantation of a right ventricular mixed venous oxygen saturationsensor connected to an implantable haemodynamic monitor. Themonitor provided a continuous measure of oxygen saturation viaa radio-telemetry link to a metabolic cart capable of measurementof breath-by-breath oxygen consumption. Cardiac output was computedusing oxygen consumption, mixed venous oxygen saturation, arterialoxygen saturation by pulse oximetry and haemoglobin oxygen capacity. Biosensor-derived oxygen saturation compared to blood samplesfrom the pulmonary artery showed an excellent correlation overtime, r²=0.94 (implant), r²=0.91 (6–11 months). Therewas a strong correlation between semi-invasive-determined cardiacoutput using the biosensor and the invasive technique, whichpersisted over the entire follow-up period. Repeated semi-invasive cardiac output measurements using animplanted haemodynamic monitoring system in chronic heart failurepatients is feasible and the data may be of value for optimizingtherapy.     

Continuous cardiac output monitoring by the Fick method

Current methods for longitudinal assessment of cardiac output in severely ill patients are intermittent only and in many respects appear unsatisfactory. We have developed a computerized on-line system for continuous Fick cardiac output monitoring, utilizing fiberoptic arterial and pulmonary arterial probes with a metabolic analyzer for VO₂. In 15 patients, cardiac output ranged 1.9–6.8 L/min and 12 were within 5% of thermodilution values. Continuous output monitoring during interventions in two patients (saline infusion and coronary angioplasty) illustrate the utility of the technique. Two additional patients had unsatisfactory VO₂ data due to low airflow velocity. The results of this pilot study suggest that cardiac output monitoring by the Fick method may have clinical and investigational uses in intensive care units and during cardiac catheterization or surgical procedures. © 1993 Wiley-Liss, Inc.     

A comparison of a continuous noninvasive arterial pressure (CNAP™) monitor with an invasive arterial blood pressure monitor in the cardiac surgical ICU

Accurate measurement and display of arterial blood pressure is essential for rational management of adult cardiac surgical patients. Because of the lower risk of complications, noninvasive monitoring methods gain importance. A newly developed continuous noninvasive arterial blood pressure (CNAP?) monitor is available and has been validated perioperatively. In a prospective study we compared the CNAP? monitoring device with invasive arterial blood pressure (IAP) measurement in 30 patients in a cardiac surgical Intensive Care Unit (ICU). Patients were either mechanically ventilated or spontaneously breathing, with or without inotropes. CNAP? was applied on two fingers of the hand contralateral to the IAP monitoring catheter. Systolic, diastolic and mean pressure data were recorded every minute for 2 h simultaneously for both IAP and CNAP?. Statistical analysis included construction of mountain plot and Bland Altman plots for assessing limits of agreement and bias (accuracy) calculation. Three thousand and six hundred pairs of data were analyzed. The CNAP? systolic arterial pressure bias was 10.415 mmHg and the CNAP? diastolic arterial pressure bias was -5.3386 mmHg; the mean arterial pressure (MAP) of CNAP? was close to the MAP of IAP, with a bias of 0.03944 mmHg. The Bland Altman plot showed a uniform distribution and a good agreement of all arterial blood pressure values between CNAP? and IAP. Percentage within limits of agreement was 94.5%, 95.1% and 99.4% for systolic, diastolic and MAP. Calculated limits of agreement were -4.60 to 25.43, -13.38 to 2.70 and -5.95 to 6.03 mmHg for systolic, diastolic and mean BP, respectively. The mountain plot showed similar results as the Bland Altman plots. We conclude CNAP? is a reliable, noninvasive, continuous blood pressure monitor that provides real-time estimates of arterial pressure comparable to those generated by an invasive arterial catheter system. CNAP? can be used as an alternative to IAP.     

Invasive hemodynamic assessment in heart failure

Routine cardiac catheterization provides data on left heart, right heart, systemic and pulmonary arterial pressures, vascular resistances, cardiac output, and ejection fraction. These data are often then applied as markers of cardiac preload, afterload, and global function, although each of these parameters reflects more complex interactions between the heart and its internal and external loads. This article reviews more specific gold standard assessments of ventricular and arterial properties, and how these relate to the parameters reported and utilized in practice, and then discusses the re-emerging importance of invasive hemodynamics in the assessment and management of heart failure.     

The evaluation of hemodynamics in post thoracic esophagectomy patients

BACKGROUND/AIMS: Thoracic esophagectomy is one of the most invasive operations, and it is necessary to have a precise understanding of postoperative hemodynamics in order to maintain normal circulation. PiCCO (pulse contour cardiac output, Pulsion Medical Systems; Munich, Germany), a new technique based on an arterial thermodilution technique, allows the measurement of intra-thoracic blood volume index (ITBVI), which has been reported to be a useful parameter for cardiac preload. In this study, changes of ITBVI were analyzed after thoracic esophagectomy using the PiCCO system. Simultaneously, the patient's circulating blood volume (cBV) and cardiac index (CI) were measured using dye densitometry and the relation between the CI and ITBVI was evaluated. METHODOLOGY: The PiCCO system was introduced in 20 patients immediately after thoracic esophagectomy, and circulatory parameters such as central venous pressure (CVP), and ITBVI were measured on ICU Days (ICUD) 1, 2 and 3. cBV and CI were simultaneously measured using the Dye Densitogram (DDG) Analyzer System (Nihon Koden, Tokyo, Japan). RESULTS: The mean fluid balance during the operation was 3462 +/- 1341mL. CI was 3.8 +/- 0.7L/min/m2 on ICUD 1, 4.4 +/- 0.8L/min/m2 on ICUD 2, and 4.3 +/- 1.OL/ min/m2 on ICUD 3, and postoperative hemodynamics were well maintained. The ITBVI (normal range: 850-1000mL/m2) was also well controlled with 977 +/- 216mL/m2 on ICUD 1, 1061 +/- 221mL/m2 on ICUD 2, and 1043 +/- 151mL/m2 on ICUD 3, respectively, although BV ratio (measured cBV / Japanese standard cBV based on height and weight) was less than 1.0 during the same period. Additionally, ITBVI had better correlation with CI (r = 0.559, p = 0.003) compared with CVP (r = 0.036, p = 0.861). CONCLUSIONS: Following thoracic esophagectomy, ITBVI was maintained within the normal range, in spite of a decrease in cBV. There was a correlation between ITBVI and CI, indicating that ITBVI might be a useful parameter for cardiac preload.     

Impedance cardiography: More questions than answers

Thoracic electrical bioimpedance, also known as impedance cardiography (ICG), is a noninvasive method to obtain hemodynamic measurements, including cardiac output. Recently, there has been a flurry of reports on the clinical use of ICG. Authors have suggested that ICG measurements are useful for a myriad of situations, including diagnosis of heart failure, monitoring of a patient’s clinical status, and assisting in medicine titration decisions. However, data continue to suggest poor correlation between current generation ICG devices and invasive measurements of cardiac output, especially in heart failure patients. ICG is also not able to accurately measure left ventricular filling pressures. There are limited data demonstrating any improved outcomes using ICG in the clinical setting. Given the available data, ICG use should be limited to the research setting.