快速输液条件下温度稀释法与动脉压法心输出量测定的比较

目的比较温度稀释法与动脉压法心输出量(CO)测定的不同,并观察快速输液条件下血流动力学的变化。方法选择ASAⅠ或Ⅱ级的骶骨肿瘤手术患者10例,麻醉诱导后,放置Swan-Ganz导管、FloTrac传感器和Vigileo监护仪,温度稀释法间断测定心输出量(ICO),动脉压法测定心输出量(APCO)。手术开始前30min内输注10ml/kg羟乙基淀粉130/0.4注射液,测定液体输注前后HR、MAP、CVP、肺动脉楔压(PAWP)、ICO、每搏量变异度(SVV)、APCO、每搏输出量指数(SVI)。采用Bland-Altman分析,比较两种方法测量CO的差异。结果 APCO-ICO的均数为-0.10L/min,95%CI为-1.14～0.94L/min。(APCO+ICO)/2的均数为5.97L/min,与95%区间的最大绝对值1.14L/min相比临床可以接受。快速液体后,CVP、PAWP、APCO和SVI明显升高(P<0.05或P<0.01);而SVV明显低于输液前(P<0.01);HR和MAP无明显变化。结论动脉压法测定CO与温度稀释法相关性好,可为围术期提供有效的血流动力学监测。     

肝移植术中连续温度稀释法监测心排血量的准确性

目的 评价肝移植术中连续温度稀释法监测心排血量(CO)的准确性.方法 13例非静脉-静脉转流原位肝移植术病人,术中采用Abbott Opti-Q CCO/SvO2连续心排血量仪监测CO(CCO);并于麻醉诱导后20、40、60、90、120 min、下腔静脉阻断5、15、25、35、45 min和下腔静脉开放5、15、25、60、90、120min时采用单次温度稀释法监测CO(BCO),连续测定3次,取其平均值;于BCO测定前后取两次CCO的平均值为该时点的CCO.计算各时点CCO与BCO间的相关系数,采用Bland-Altman法进行一致性检验.结果 共收集196对CO数据,CCO范围为1.9～17.9 L/min,BCO范围为2.1～18.3L/min.与其余时点比较.下腔静脉阻断5 min和下腔静脉开放5 min时CCO和BCO间的相关系数较低,偏离度较大,CCO监测存在明显的响应时间延迟现象;其他时点CCO和BCO间的偏离度为-0.18L/min,95%可信区间为-0.32～-0.03 L/min,一致性界限为-2.09～1.73 L/min,其下限的95%可信区间为-2.34～-1.84 L/min,其上限的95%可信区间为1.48～1.99 L/min.CCO和BCO的重复系数分别为0.36和0.86 L/min.CCO与BCO的平均值与CCO的差值为(0.09±0.49)L/min,CCO的相对误差为4.6%±1.7%.结论 肝移植术中血液动力学改变显著时,CCO存在明显的响应时间延迟现象;而在血液动力学相对稳定时,CCO和BCO之间缺乏良好的一致性,但CCO监测在临床上是可接受的.     

手术中用三维经食道超声心动图测量心输出量的准确性和可行性

背景本研究中,我们试图用三维经食道超声心动图（3DTEE）确定心输出量,并评价其在手术中应用的可行性。方法同时用3DTEE和热稀释．法测定20例行心脏手术的患者在临床上稳定的体外循环前期时的心输出量。结果用这2种方法测定心输出量之间的相关系数是0．86。3DTEE的平均偏差是0．27L／min,范围是一1．64—2．17L／min（一致性为±35％）。平均三维数据采集时间为43秒,数据后处理时间为7分钟。结论可以用3DTEE来测量心输出量,并且这种方法在围手术期是可行的。虽然这种方法同热稀释法相比差异有显著性,且一致性较差,但是与热稀释法有很好的相关性。     

无创部分二氧化碳复吸技术心输出量测定的临床研究

目的 根据部分CO_2重复呼吸法和经修改后Fick方程原理,对无创监测心输出量(CO)的临床和技术性能作评估。方法 在腹主动脉瘤手术中,对15例患者同时用部分CO_2重复呼吸法(CO_(NICO))和热稀释法(CO_(TD))CO测定;并由NICO所估计的肺内分流和标准分流方程所获数值作比较。结果 CO_(NICO)和CO_(TD)之间相关极好(r=0.90),NICO检测的CO仅有很小的偏差(—0.21L/min),两者之间一致性范围(±2SD)为—1.89～1.74L/min。与动脉血和经Swan-Ganz导管采集混合静脉血血气所计算的标准分流比较,肺内分流偏低约10％。结论 临床评价显示,部分CO_2重复呼吸法提供了一个有用的无创CO监测技术。此技术虽不能完全取代肺动脉插管,但它可用于监测大部分择期血管外科手术患者的血液动力学。     

心排血量监测的指示剂稀释技术：基本原理、局限性与展望

对于心脏并发症风险高的危重患者，尤其对于已有心血管并存疾病的患者，心排血量的监测是评估血流动力学的重要基石。30多年来，通过肺动脉导管用快速灌注热稀释法评估心排血量的方法已作为高级血流动力学监测的“临床标准”被广泛认可。本文回顾了这一临床标准，以及目前同样源于指示剂稀释技术的替代方法，如经心肺热稀释和锂稀释技术。这篇综述不但描述了实施每种指示剂稀释法的基本技术原理和各自的特征，还概述了其局限性。     

腹腔镜胆囊切除术中患者肾血流量的变化

目的 探讨腹腔镜胆囊切除术中患者肾血流量的变化.方法 择期行腹腔镜胆囊切除术患者32例,年龄18～64岁.气管插管后经口置入食管超声探头,采用经食管超声心动图分别于气腹前(基础状态)、气腹1、5、10、15、20、30 min、气腹停止后1、5 min时测量左肾动脉主干内径、主动脉内径、左肾动脉主干血流速度时间积分和降主动脉血流速度时间积分,计算左肾血流量(LRAF)、降主动脉血流量(DAF)和LRAF与DAF的比值(LRAF/DAF).分析LRAF和DAF的最大下降时点、最大下降量和最大下降百分比.结果 与基础值比较,气腹中各时点LRAF和DAF下降(P＜0.05),气腹停止后差异无统计学意义(P＞0.05);气腹中和气腹停止后各时点LRAF/DAF差异无统计学意义(P＞0.05).气腹中LRAF和DAF最大下降时间点分别为8.9 min[95%可信区间(95%CI)5.5～12.4 min]和6.7 min(95%CI4.0～9.5 min),最大下降量分别为130 ml/min(95%CI 96～163 ml/min)和1.57 L/min(95%CI1.20～1.95 L/min),最大下降百分比分别为40%(95%CI 31%～49%)和38%(95%CI 31%～44%).结论 腹腔镜胆囊切除术中气腹1～30 min时肾血流量下降,下降的最大程度约40%,时间在气腹9 min左右,其下降的原因与心输出量下降有关.     

南京市孕前健康体检男性精液质量及其影响因素的初步调查分析

目的:初步了解本地区孕前健康体检男性精液质量现状及其影响因素,为制定有效干预措施提供依据。方法:对符合纳入标准的687例本地孕前男性进行问卷调查,并进行精液质量分析。结果:精子浓度中位数为63.30×106/ml,95%CI范围为(19.88~119.0)×106/ml;a级精子百分率中位数为33.03%,95%CI范围为(19.38~55.05)%;(a+b)级精子百分率中位数为52.08%,95%CI范围为(39.53~69.37)%;畸形精子百分率中位数为91.75%,95%CI范围为(69~100)%;精浆弹性蛋白酶中位数为195.55 ng/ml,95%CI范围为(76.16~3 330.38)ng/ml;精浆锌中位数为7.62μmol/L,95%CI范围为(1.50~23.45)μmol/L;UU阳性率42.4%,CT阳性率0.3%,加德纳菌(GV)阳性率2.4%;配偶有不良妊娠史精子DNA碎片指数(DFI)中位数为20.25%,95%CI范围为(2.15~68.25)%。多因素Logistic回归分析表明:有久坐习惯及精神压力大是精子活力降低的独立危险因素,OR值分别为1.772、1.567,95%CI分别1.211~2.592、1.081~2.27。结论:南京地区孕前男性精子质量不容乐观,改变不良习惯、减轻精神压力可能有助于改善精子质量。     

鲍曼不动杆菌和肺炎克雷伯菌对替加环素体外敏感性检测的方法学评估

目的 评估不同药敏试验方法检测鲍曼不动杆菌和肺炎克雷伯菌对替加环素的体外药敏结果.方法 连续收集2012年1月至3月临床感染患者分离的50株耐碳青霉烯类鲍曼不动杆菌(CRAB)和49株肺炎克雷伯菌,采用微量肉汤稀释法、Vitek-2法、MIC Test Strip(MTS)法及纸片扩散法分别测定替加环素对两种细菌的敏感性,并以微量肉汤稀释法为参考方法,评估Vitek-2法、MTS法及纸片扩散法与参考方法的一致性.结果 按照美国食品药品监督局(FDA)的判断标准,微量肉汤稀释法、Vitek-2法和MTS法检测替加环素对CRAB和肺炎克雷伯菌的敏感性分别为94.0％/91.8％,68.0％/91.8％和90.0％/91.8％.对于CRAB,Vitek-2法和MTS法与参考方法的基本一致率/分类一致率(EA/CA)分别为94.0％/72.0％和92.0％/90.0％,66.0％ (33/50)的菌株Vitek-2法检测的MIC值比参考方法高1～2个稀释度,MTS法检测的MIC值存在32.0％ (16/50)偏高及22.0％ (11/50)偏低;对于肺炎克雷伯菌,Vitek-2法和MTS法与参考方法的EA/CA分别为95.9％/98.0％和83.7％/91.8％,36.7％ (18/49)的菌株Vitek-2法检测的MIC值比参考方法低1～3个稀释度,79.6％(39/49)的菌株MTS检测的MIC值比参考方法低1～3个稀释度.Vitek-2法和MTS法检测两种细菌均未出现重大误差(VME)和大误差(ME).纸片扩散法与参考方法相比,对于CRAB,采用敏感/耐药(≥14 mm/≤10 mm)折点,CA为94.0％,高于Jones等推荐的折点(≥16 mm/≤12 mm,CA为82.0％);对肺炎克雷伯菌,采用敏感/耐药(≥14 mm/≤10 mm)折点,CA为93.9％,高于FDA中肠杆菌的折点(≥19 mm/≤14 mm,CA为67.3％).结论 对于CRAB菌株,MTS法与微量肉汤稀释法的一致性较高,MIC结果存在一定程度的偏差;对于肺炎克雷伯菌,Vitek-2法与微量肉汤稀释法的一致性较高,MIC结果存在一定程度的偏低;纸片扩散法与微量肉汤稀释法一致性较低,针对不同细菌其判定折点需进一步研究.     

部分二氧化碳重复吸入法与温度稀释法测定心排血量的相关性研究

目的　研究部分二氧化碳重复吸入法和温度稀释法监测心排血量 (CO)的相关性。方法　重症监护病房 (ICU) 1 5例危重患者 ,在呼吸机辅助控制通气条件下 ,采用美国无创心肺功能监测仪 (NICO)用部分二氧化碳重复吸入法 (RB)连续监测无创心排血量 (RBco) ,并同时采用温度稀释法测定心排血量 (TDco) ,两种方法所测CO值进行自体配对相关性研究。结果　配对t检验示两种方法测定的CO值无显著性差异 (P >0 0 5 ) ,相关回归分析示相关系数为 0 90 ,回归方程为RBco =0 81TDco +1 2 5 ,偏离为 0 2 0 ,精确度为 0 78。结论　部分二氧化碳重复吸入是一种简便、快捷、连续、无创的CO测定方法 ,该法与温度稀释法有良好的相关性 ;在无条件行肺动脉漂浮导管插入有创心功能监测的医院 ,这种无创CO监测是一种安全可靠的选择     

温度稀释法测定心输出量的局限性

经肺动脉导管(PAC)采用温度稀释技术可测定心输出量(CO),通过PAC向右房注入定量冷溶液,经距PAC末端4cm处的热敏电阻单臂电桥阻抗可探测肺动脉血液温度的变化,通过计算机算出温度稀释曲线下面积,结合注入液体的容积可推算出CO。除温度稀释再循环量很小以外(约为曲线峰值的4%),此曲线的形状与染料稀释曲线相似。温度稀释曲线上升很快,紧接呈指数     

Measuring cardiac output in one-lung ventilation: a comparison of pulmonary artery and transpulmonary aortic measurements in pigs

OBJECTIVE: The agreement between cardiac output measurements via pulmonary artery thermodilution (CO[PA]) and transpulmonary aortic thermodilution (CO[AT]) during one-lung ventilation was studied. DESIGN: Animal study with repeated simultaneous measurements comparing 2 cardiac output measurement techniques. SETTING: Experimental animal facility of a university department. PARTICIPANTS: Forty-eight female pigs (26-42 kg). INTERVENTIONS: The pigs were anesthetized, tracheally intubated, and mechanically ventilated. After placement of an aortic thermistor catheter via the femoral artery and a pulmonary artery catheter, a double-lumen tube was placed via tracheotomy. During one-lung ventilation in each animal, 3 measurements with pulmonary artery thermodilution and transpulmonary aortic thermodilution were performed in different hemodynamic states. Both thermistors were connected to 1 computer system, and 144 simultaneous cardiac output measurements were analyzed. MEASUREMENTS AND MAIN RESULTS: Linear regression analyses revealed a close relationship between the 2 methods: CO(AT) = 0.81 CO(PA) + 1.04 (L/min) (r = 0.96, p < 0.0001). Bland-Altman analysis showed that CO(AT) was slightly higher than the CO(PA) with a bias of 0.2 +/- 0.5 L/min. However, in higher CO states, an inversion of this relationship was found, possibly because of indicator loss and recirculation. CONCLUSIONS: The pulmonary artery thermodilution and the transpulmonary aortic thermodilution techniques both accurately measure cardiac output during one-lung ventilation.     

Arterial thermodilution: an alternative to pulmonary artery catheter for cardiac output assessment in burn patients

STUDY OBJECTIVE: To study the agreement between cardiac output measurements with the pulmonary artery catheter and with the transpulmonary thermodilution technique in patients with burns. DESIGN: Prospective, clinical study. PATIENTS: 23 patients with serious burns and an abbreviated burn severity index score (ABSI)>6. SETTING: intensive care unit for severely burned in a burn center in Germany. RESULTS: A total number of 218 cardiac output measurements obtained during the first 72 h postburn were analysed. In the pulmonary artery group, mean cardiac index was 3.93 l/min/m2 and ranged from 0.96 to 9.58. In the transpulmonary group the cardiac index measurements ranged from 0.96 to 9.61 with a mean of 4.0 l/min/m2. During the entire observation period cardiac index was consistently higher in the transpulmonary group than in the pulmonary artery group with a bias of 0.32 l/min/m2 and a standard deviation (S.D.) of 0.29 l/min/m2. Linear regression analysis revealed CI(arterial)=0.98xCI(pulm)+0.22l/min/m2 (r=0.9678, P<0.038). Bias and precision to each time point according to Bland and Altman demonstrated a good agreement between both techniques. Conclusion: The transpulmonary thermodilution offers an attractive, less invasive alternative to the pulmonary artery catheter in patients with burns. Arterial thermodilution for CO measurements is as precise as PA thermal dilution, and CO(pulm) can be replaced by CI(arterial) when basic methodological principles are respected.     

The level of cardiac output affects the relationship and agreement between pulmonary artery and transpulmonary aortic thermodilution measurements in an animal model

OBJECTIVE: The authors investigated the relationship between pulmonary artery and transpulmonary aortic thermodilution cardiac output measurements under conditions of increasing cardiac output (CO). DESIGN: Animal study with repeated simultaneous measurements comparing 2 cardiac output measurement techniques. SETTING: Experimental animal facility of a university hospital. PARTICIPANTS: Ten female pigs. INTERVENTIONS: In anesthetized pigs, an aortic thermistor catheter and a pulmonary artery catheter (PAC) were inserted. Then dobutamine was infused under continuous cardiac output (CCO) monitoring to target different levels of CO. After each L/min increase of CCO simultaneous aortic and PAC thermodilution, CO measurements were performed by using a bolus injection of cooled normal saline and the amount of thermal indicator loss (TL) was calculated. MEASUREMENTS AND MAIN RESULTS: Pooled analysis of CO data with the method of Bland and Altman showed that aortic thermodilution CO was higher than PAC thermodilution CO with a bias of 3.8% +/- 11.1%. The range of TL was 30.4% to -10.1%. Differential analysis according to the range of CO revealed that, in each animal under conditions of low CO, aortic thermodilution CO was higher than PAC thermodilution CO, whereas results were inverse under conditions of high CO. CONCLUSIONS: The authors concluded that the amount of CO differentially affects the relationship between aortic and PAC thermodilution CO. TL and recirculation may be the explanation for this finding.     

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.     

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.     

Transpulmonary thermodilution cardiac output measurement using the axillary artery in critically ill patients

STUDY OBJECTIVE: To compare cardiac output (CO) as measured by the arterial thermodilution technique using only a central venous catheter and an arterial catheter inserted into the axillary artery, with conventional CO measurement with thermodilution using a pulmonary artery (PA) catheter (PAC). DESIGN: Prospective clinical study in which each patient served as his/her own control. SETTING: General ICU of a large tertiary-care teaching hospital. PATIENTS: 22 patients who required invasive hemodynamic monitoring in the ICU. INTERVENTIONS AND MEASUREMENTS: CO measurements made using the PAC (COpa) were compared to bolus arterial thermodilution measurements (COax). The significance of acute changes in the continuous CO measurements during acute hemodynamic episodes was observed. MAIN RESULTS : The correlation between the two techniques (COpa and COax) was R(2) = 0.82. There was a tendency for 5% overestimation of COpa by the COax. The SEM% (SEM/average CO) for COax and COpa was 2.6% and 3.2%, respectively. The bias between measurements was 0.27 +/- 0.67 L/min, and the limits of agreement (mean difference +/- 2 SD) from minus 1.07 L/min to 1.63 L/min. CONCLUSIONS: In critically ill patients, in whom the measurement of CO is required, arterial thermodilution, using a central vein and the axillary artery is accurate and reproducible.     

Comparison of cardiac output measurements by arterial trans-cardiopulmonary and pulmonary arterial thermodilution with direct Fick in septic shock

BACKGROUND AND OBJECTIVE: The aim of this study was to compare cardiac output (CO) measurements by arterial trans-cardiopulmonary thermodilution (ATD) and pulmonary arterial thermodilution (PATD) with CO estimated on the basis of the Fick calculation via a metabolic monitor in septic shock. METHODS: In a prospective animal study 20 anaesthetized, ventilated pigs (20.9 +/- 1.9 kg) were investigated. Septic shock was induced with faecal peritonitis. A pulmonary artery catheter was used for conventional measurement of CO. Simultaneously ATD was measured with a thermistor tipped catheter inserted into right carotid artery. Whole body oxygen consumption was measured by indirect calorimetry. Eighty data pairs of simultaneous CO measurements were analysed. RESULTS: CO measured with Fick and that measured with PATD were significantly correlated (r = 0.94, r = 0.87, P < 0.001). Mean CO measured by PATD was 94.3 +/- 40.1 mL min(-1) kg(-1). Bias was 10.1 mL min(-1) kg(-1) (95% confidence interval (CI): 6.0-14.2 mL min(-1) kg(-1)) with limits of agreement of -26.8 to 47.0 mL min(-1) kg(-1). Correlation between Fick derived CO estimation and ATD CO was similar (r = 0.91, r2 = 0.83, P < 0.001). Mean CO measured by trans-cardiopulmonary thermodilution was 104.3 +/- 43.2 mL min(-1) kg(-1). Bias was 0.75 mL min(-1) kg(-1) (95% CI: -3.8 to 5.3 mL min(-1) kg(-1)) with limits of agreement of -39.7 to 41.2 mL min(-1) kg(-1). CONCLUSIONS: Even during haemodynamic instability in septic shock the correlation of arterial trans-cardiopulmonary thermodilution and PATD derived CO with direct Fick was good. As arterial trans-cardiopulmonary thermodilution is less invasive than PATD, the former may offer practical advantages.     

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.     

Cardiac output--pulse contour analysis vs. pulmonary artery thermodilution

BACKGROUND: The aims of this study were to determine the agreement between pulmonary artery thermodilution (PA-TD), transpulmonary thermodilution (TP-TD) and the pulse contour method, and to test the ability of the pulse contour method to track changes in cardiac output. METHODS: Cardiac output was determined twice before cardiac surgery with both PA-TD and TP-TD. The precision (two standard deviations of the difference between repeated measurements) and agreement of the two methods were calculated. Post-operatively, cardiac output was determined with the PA-TD and pulse contour methods, and the bias and limits of agreement were again calculated. Finally, in patients with heart rates below 60 beats/min or a cardiac index of less than 2.5 l/min/m2, atrial pacing was started and the haemodynamic consequences were monitored with the PA-TD and pulse contour methods. RESULTS: Twenty-five patients were included. The precisions of PA-TD and TP-TD were 0.41 l/min [95% confidence interval (CI), +/- 0.07] and 0.48 l/min (95% CI, +/- 0.08), respectively. The bias and limits of agreement between PA-TD and TP-TD were - 0.46 l/min (95% CI, +/- 0.11) and +/- 1.10 l/min (95% CI, +/- 0.19), respectively. Post-operatively, the bias and limits of agreement between the PA-TD and pulse contour methods were 0.07 l/min and +/- 2.20 l/min, respectively. The changes in cardiac output with atrial pacing were in the same direction and of the same magnitude in 15 of the 16 patients. CONCLUSION: The precision of cardiac output measurements with PA-TD and TP-TD was very similar. The transpulmonary method, however, overestimated the cardiac output by 0.46 l/min. Post-operatively, cardiac output measurements with the PA-TD and pulse contour methods did not agree, but the pulse contour method reliably tracked pacing-induced changes in cardiac output.     

Cardiac output monitoring: aortic transpulmonary thermodilution and pulse contour analysis agree with standard thermodilution methods in patients undergoing lung transplantation

PURPOSE: The PiCCO System is a relatively new device allowing intermittent cardiac output monitoring by aortic transpulmonary thermodilution technique (Aorta intermittent) and continuous cardiac output monitoring by pulse contour analysis (Aorta continuous). The objective of this study was to assess the level of agreement of Aorta intermittent and Aorta continuous with intermittent (PA intermittent) and continuous cardiac output (PA continuous) measured through a special pulmonary artery catheter (Vigilance System SvO(2)/CCO Monitor) in patients undergoing single- or double-lung transplantation. METHODS: Measurements were obtained in 58 patients: at four time points in patients undergoing single-lung transplantation and at six time points in those undergoing double-lung transplantation. Bland and Altman and correlation analyses were used for statistical evaluation. RESULTS: We found close agreement between the techniques. Mean bias between Aorta intermittent and PA intermittent and between Aorta continuous and PA continuous was 0.18 L x min(-1) (2SD of differences between methods = 1.59 L x min(-1)) and -0.07 L x min(-1) (2SD of differences between methods = 1.46 L x min(-1)) respectively. Mean bias between PA continuous and PA intermittent and Aorta continuous and PA intermittent was 0.15 L x min(-1) (2SD of differences between methods = 1.39 L x min(-1)) and 0.08 L x min(-1) (2SD of differences between methods = 1.43 L x min(-1)). CONCLUSION: Measurements with the aortic transpulmonary thermodilution technique give continuous and intermittent values that agree with the pulmonary thermodilution method which is still the current clinical standard.