血管外肺水监测及其临床应用

血管外肺水(EVLW)与肺水肿的发展密切相关,胸腔内血容量(ITBV)可直接了解心脏容量负荷。通过监测EVLW和ITBV并进行相应的液体管理可为危重病患者的血流动力学管理提供新的思路。本文将具体阐述在动物实验和临床中常用的测定血管外肺水的方法并对其临床意义及应用进行综述。     

Combined early fluid resuscitation and hydrogen inhalation attenuates lung and intestine injury

AIM:To study the effects of combined early fluid resuscitation and hydrogen inhalation on septic shockinduced lung and intestine injuries.METHODS:Wistar male rats were randomly divided into four groups:control group(Group A,n = 15);septic shock group(Group B,n = 15);early fluid resuscitation-treated septic shock group(Group C,n = 15);and early fluid resuscitation and inhalation of 2% hydrogentreated septic shock group(Group D,n = 15).The activity of hydroxyl radicals,myeloperoxidase(MPO),superoxide dismutase(SOD),diamine oxidase(DAO),and the concentration of malonaldehyde(MDA) in the lung and intestinal tissue were assessed according to the corresponding kits.Hematoxylin and eosin staining was carried out to detect the pathology of the lung and intestine.The expression levels of interleukin(IL)-6,IL-8,and tumor necrosis factor(TNF)-α in lung and intestine tissue were detected by enzyme-linked immunosorbent assay method.The expression levels of Fas and Bcl2 in lung tissues were determined by immunohistochemistry and Western blotting.RESULTS:Septic shock elicited a significant increase in the levels of MDA(10.17 ± 1.12 nmol/mg protein vs 2.98 ± 0.64 nmol/mg protein) and MPO(6.79 ± 1.02 U/g wet tissue vs 1.69 ± 0.14 U/g wet tissue) in lung tissues.These effects were not significantly decreased by Group C pretreatment,but were significantly reduced by Group D pretreatment(MDA:4.45 ± 1.13 nmol/mg protein vs 9.56 ± 1.37 nmol/mg protein;MPO:2.58 ± 0.21 U/g wet tissue vs 6.02 ± 1.16 U/g wet tissue).The activity of SOD(250.32 ± 8.56 U/mg protein vs 365.78 ± 10.26 U/mg protein) in lung tissues was decreased after septic shock,and was not significantly increased by Group C pretreatment,but was significantly enhanced by Group D pretreatment(331.15 ± 9.64 U/mg protein vs 262.98 ± 5.47 U/mg protein).Histological evidence of lung hemorrhage,neutrophil infiltration and overexpression of IL-6,IL-8,and TNF-α was observed in lung tissues,all of which were attenuated by Group C and further alleviated by Group D pretre     

血管外肺水的监测与治疗研究进展

血管外肺水(extravacular lung water,EVLW)是指分布于血管外的液体,由细胞内液、肺泡内液和肺间质液组成,反映了肺水肿程度。因此对EVLW进行动态观察和定量监测,已成为肺水肿基础与临床研究的热点。EVLW的监测方法分为有创和无创,文章对现今使用的EVLW的监测方法及其原理进行了综述,并针对近年来常用临床措施(机械通气、液体复苏、血管活性药物的应用)对EVLW的影响作了简单的总结。     

Lung management during cardiopulmonary bypass: Influence on extravascular lung water

Progressive respiratory insufficiency secondary to cardiopulmonary bypass (CPB) is still a hazard after cardiac surgery. Pathophysiologically, impaired capillary endothelial integrity seems to be the fundamental lesion, followed by increased interstitial fluid accumulation. The reasons for this pulmonary damage age controversial; however, management of the nonperfused lungs during CPB has been widely neglected and may be partly responsible. In this study, 90 patients undergoing coronary artery bypass grafting were randomly divided into six groups (15 patients each) with different management of the lungs during CPB: group 1, lungs collapsed (0/0); group 2, static inflation with +5 cm H₂O and F₁O₂ 1.0 (+5/1.0); group 3, static inflation with +5 cm H₂O and F₁O₂ 0.21 (+5/0.21); group 4, static inflation with +15 cm H₂O and F₁O₂ 1.0 (+15/1.0); group 5, static inflation with +15 cm H₂O and F₁O₂ 0.21 (+15/0.21); and group 6, controlled mechanical ventilation as before start of CPB (positive end-expiratory pressure [PEEP +5 cm H₂O; F₁O₂ 1.0) (ventilation). In addition to hemodynamic monitoring, extravascular lung water (EVLW) was measured by means of a double-indicator dilution technique with heat and indocyanine green. Measurements were performed after induction of anesthesia, before onset of CPB, and immediately after weaning from bypass, as well as 60 minutes and 5 hours after termination of CPB. Pulmonary gas exchange (PaO₂) and intrapulmonary shunting (Q̇s/Q̇t) were also measured. Starting from comparable, normal baseline values, EVLW was increased in all groups after weaning from CPB, with the most pronounced increase in group 4 (maximum, +35%) and group 5 (+40%). Five hours after CPB, lung water content had normalized, except in groups 4 and 5, which still had values higher than those prior to CPB. (PaO₂) decreased most in these groups (group 4, −109 mm Hg; group 5, −130 mm Hg), and Q̇s/Q̇t increased significantly (group 4, +6.7%; group 5, +6.9%) after bypass. It is concluded that the handling of the lungs during CPB significantly influenced changes in EVLW after bypass. Static inflation with high levels of PEEP, particularly in combination with 100% oxygen, should be avoided due to the risk of an increase in lung water content. Static inflation with moderate PEEP and air seems to be the best way to optimize postbypass pulmonary function.     

Age and cardiac surgery. Influence on extravascular lung water

This study was designed in order to evaluate the influence of advanced age on extravascular lung water (EVLW) content. Forty patients undergoing aortocoronary bypass grafting were prospectively divided into two groups according to age below 45 years (group 1; n = 20) and above 65 years (group 2; n = 20). The EVLW was measured using the double indicator dilution technique with indocyanine green as the nondiffusible indicator. Starting from similar baseline values before extracorporeal circulation (ECC), EVLW significantly increased after ECC only in the elderly patients (max + 1.51 ml/kg), whereas lung water content in the other group remained almost unchanged. No significant differences in left ventricular filling pressure (PCP) could be observed. Regression analysis revealed a strong positive correlation between age and increase in EVLW after ECC. Simultaneously, PaO2 was decreased (-114 mm Hg) and intrapulmonary shunt fraction (Qs/Qt) was increased only in this group. Within the next five hours after ECC, lung water returned nearly to baseline values and pulmonary function was normalized. It is concluded that increasing age was associated with a transient increase in EVLW after ECC due to a more pronounced fragility of the pulmonary endothelial membrane or/and to depressed left ventricular performance.     

Theoretical and practical considerations of measuring extravascular lung water

The volume of extravascular lung water is currently measured in vivo from the difference in mean transit times of the extrapolated first-pass dilution curves of two indicators, one diffusible and the other confined to the intravascular space. To overcome the limitations of this method, one can prolong the measurement interval, introduce a highly diffusible indicator, or both. In the first case, recirculating indicators are measured and included in the computation by deconvolution of the mean transit time through the lung. In the second case, heat is used as the water indicator. In the third case, not yet explored, recirculating heat would be measured and long thermal transit times uncovered. In view of the complexity of the deconvolution method and the pitfalls of the thermal dilution method, a radiographic score of pulmonary edema may be more useful clinically to assess the volume of extravascular lung water in patients with heart disease or adult respiratory distress syndrome.     

Determination of central blood volume and extravascular lung water

In patients undergoing thoracic surgery central blood volume is subject to large variations and extravascular lung water may change critically due to fluid shifts. Therefore, an accurate monitoring of these parameters, in particular under perioperative conditions, seems to be desirable. This study describes an improved method for the measurement of intrathoracic volumes. Experiments were carried our in 9 mongrel dogs under piritramide-N2O anesthesia. In order to produce low cardiac output in combination with uneven distribution of perfusion, measurements were performed under base line conditions and after postural changes. Indicators (cold and indocyanine green dye) were injected into the v. cava and indicator kinetics were recorded from the pulmonary artery and aorta using thermistor-fiberoptic catheters. The transport functions of cold and dye were computed from the corresponding pairs of dilution curves. From the transport functions, the mean transit times of the intravascular (dye) and diffusible (cold) indicator were determined. Central blood volume and extravascular lung thermal volume were calculated from the mean transit times and a thermodilution cardiac output. Results: Under base line conditions, central blood volume was 15.3 +/- 2.5 ml/kg body weight. In orthostasis, a significant and reversible reduction to 11.6 +/- 2.4 ml/kg body weight was found. Cardiac output fell significantly from 3.3 +/- 0.5 to 2.4 +/- 1.1. l/min. In contrast, the slight decrease of extravascular lung thermal volume was not statistically significant. It is concluded that the method presented is sensitive enough to detect even small changes of central blood volume.(ABSTRACT TRUNCATED AT 250 WORDS)     

Efficacy of pressure support ventilation dependent on extravascular lung water

Continuous positive-pressure ventilation and PSV were compared prospectively in patients at a surgical intensive care unit. All patients suffered from mild to moderate ARI (PaO2/FIO2 of 125 to 350 mm Hg). The patients were randomly assigned to a PSV group (n = 28) or a control group with continued CPPV (n = 27). The usual hemodynamic and oxygenation variables, ITBV, and extravascular lung water (ETV) were assessed before and six hours after switching to PSV. The changes (d) of PaO2/FIO2, RI, and P(A-a)O2 were used for evaluation of the effect of PSV. Significant correlations were found between the ETV(CPPV) and dPaO2/FIO2 (r = -0.672), ETV(CPPV) and dRI (r = 0.722), and ETV(CPPV) and dP(A-a)O2 (r = 0.601), which led to the conclusion that the level of ETV determined the efficacy of PSV. In the subgroup with ETV less than 11 ml/kg (n = 15), PSV significantly improved PaO2/FIO2 (248 to 286 mm Hg), RI (1.55 to 1.22), ITBV (801 to 888 ml/m2), cardiac index (4.21 to 4.76 L/min.m2), stroke index (42.2 to 48.1 ml/m2), and oxygen delivery (735 to 833 ml/min.m2). In the subgroup with ETV greater than 11 ml/kg (n = 13), PSV caused a significant deterioration of PaO2/FIO2, RI, and intrapulmonary shunt. It is concluded that in patients with moderate ARI in whom ETV is almost normal, PSV is superior to CPPV, and the efficacy of PSV is independent of the level of oxygenation during CPPV.     

肺保护与肺开放通气策略对急性呼吸窘迫综合征家兔血管外肺水的影响

目的探讨肺保护与肺开放通气策略对急性呼吸窘迫综合征(ARDS)血管外肺水(EVLWI)的影响。方法以肺泡灌洗法复制家兔ARDS模型,分为中等潮气量(VT)零呼气末正压(PEEP)组(MVZP组)、小VT零PEEP组(LVZP组)、小VT最佳PEEP组(LVBP组)和小VT最佳PEEP+控制性肺膨胀(SI)组(LVBP+SI组)。采用单指示剂热稀释法测定EVLWI。观察在不同通气条件下0、1、2和3h EVLWI的变化。结果MVZP组、LVZP组、LVBP组和LVBP+SI组EVLWI在基础时分别为(11.3±2.4)、(10.2±2.4)、(10.3±4.6)和(9.7±2.3)ml/kg,达到ARDS模型(0h)时显著升高[(22.3±5.6)、(20.0±3.8)、(25.7±9.7)和(22.5±6.2)ml/kg,P均<0.05]。在实验观察3h中,MVZP组在2、3h EVLWI[(32.0±12.2)、(36.2±12.4)ml/kg]显著高于0h[(22.3±5.6)ml/kg,P均<0.05]。LVZP组在2、3h EVLWI[(27.8±12.9)、(30.3±13.0)ml/kg]也显著高于0h[(20.0±3.8)ml/kg,P均<0.05];LVBP组1h时EVLWI为(18.5±8.1)ml/kg,与0h[(25.7±9.7)ml/kg]比较差异有统计学意义(P=0.027)。LVBP+SI组在1、2、3h各时点EVLWI分别为(16.8±6.5)、(18.0±7.1)、(15.7±2.7)ml/kg,与0h[(22.5±6.2)ml/kg]比较显著降低(P均<0.05)。与MVZP组比较,1、3h时LVBP组与LVBP+SI组EVLWI显著降低(P均<0.05)。3hLVBP+SI组EVLWI显著低于LVZP组(P<0.05)。结论肺保护与肺开放通气策略可降低EVLWI,增加肺水清除。     

C3-mediated extravascular hemolysis in PNH on eculizumab: Mechanism and clinical implications

The introduction of eculizumab, a human monoclonal antibody against the C5 component of complement, has changed radically the management of paroxysmal nocturnal hemoglobinuria (PNH). The blockade of the terminal complement pathway by eculizumab abrogates intravascular hemolysis, reduces the transfusion requirement and the risk of thrombosis in most of hemolytic PNH patients. However, in almost all PNH patients on eculizumab arises a fraction of PNH red cells that bind fragments of C3 and become a potential target of phagocytosis by macrophages. Eventually, this phagocytosis results in a variable degree of extravascular hemolysis that may reduce clinical benefits of eculizumab and, in fact, about one-fourth of patients remain transfusion-dependent.The treatment of the few PNH patients in which this de novo extravascular hemolysis become clinically relevant is still unsatisfactory. Nevertheless, the investigations of the mechanisms responsible of the extravascular hemolysis on eculizumab have resulted in the development of novel strategies for complement blockade that could overcome this condition.     

Determination of regional extravascular lung water in heart failure

The measurement of regional extravascular lung water (rELW) was evaluated by two double-indicator dilution methods both in normals and in patients with congestive heart failure. 1. Time-activity curves in various regions of the lungs were recorded with a positron camera (Cycl. Corp., model 4200) following a bolus application (H2O-15 as a diffusible and CO-15-Carboxyhemoglobin as an intravascular tracer). The mean transit times were computed and the extravascular lung water per unit of plasma volume (ELW/Vp was calculated. Investigations in 4 normals (ELW/Vp = 0.10-0.37, means = 0.22) and 7 patients (ELW/Vp = 0.08-0.57, means = 0.33) showed that due to constraints in the method a clinically useful index of rELW is not yielded with this particularly technique. 2. Total lung water (constant infusion of H2O-15), blood volume (single breath inhaled C-11-O), and extravascular lung water (ELW = total lung water - blood volume) were measured with a positron camera system under steady state conditions. This study showed a relatively homogenous distribution of rELW in 2 normals (0.10-0.14 g/cm3), whereas in 2 patients with congestive heart failure (NYHA III-IV) rELW was about twice as high as in normals and showed significant regional differences (0.17-0.34 g/cm3).     

Colloid osmotic pressure and extravascular lung water following extracorporeal circulation

With regard to Starling's equation, two factors are important for fluid regulation in pulmonary tissue: colloid osmotic pressure (COP) and hydrostatic pressure (PCP). The purpose of the study was to evaluate the relationship between COP, COP-PCP-gradient and extravascular lung water (EVLW) immediately after extracorporeal circulation (ECC). 39 consenting patients undergoing elective aorto-coronary bypass surgery received 1000 ml washed erythrocytes (w.e.; cell saver) +400 ml fresh frozen plasma (FFP) after ECC. Additionally, group I (n = 15) received 300 ml albumin 20%, group II (n = 13) 500 ml plasmaexpander (3% HES 200/0.5) and group III (n = 11) no more volume. At three different times, measurement of EVLW was performed by using double-indicator-dilution technique with indocyanine green and a microprocessed lung water computer: 15 minutes after ECC (before infusion), 45 minutes after ECC (after infusion), five hours after ECC. Application of 20% albumin led to a significant increase in COP (+67%) which was less pronounced in group II (+40%) and group III (+41%). Simultaneously, the most pronounced increase in EVLW could be observed in group I (+25%) as well. Pulmonary gas exchange in group I was more compromised (PaO2 -72 mmHg) than in group II (-38 mmHg) and group III (-50 mmHg). No correlation between EVLW and COP-PCP-gradient could be observed. In spite of a significant elevation of COP by using 20% albumin solution, EVLW increased with subsequent deterioration of pulmonary gas exchange. The presented data demonstrate no advantage of albumin 20%; if volume substitution is necessary after ECC, low concentrated plasmaexpanders (up to 10 ml/kg b.w.) may be preferred for several reasons.     

Thermal dye measurements of extravascular lung water in critically ill patients. Intravascular Starling forces and extravascular lung water in the adult respiratory distress syndrome

To assess the concurrent influence on extravascular lung water (EVLW) content of the intravascular Starling forces, the pulmonary capillary wedge pressure (PCWP), and the colloid osmotic pressure (COP), we measured EVLW by the thermal green dye technique in 174 patients with and without radiographically defined pulmonary edema; in the former group, patients with cardiac (CPE) and noncardiac (NCPE) causes of pulmonary edema were compared (study A). In 119 patients, EVLW was again measured one to three days later (study B). Patients with CPE demonstrated a significantly lower EVLW (9.3 +/- 3.9 ml/kg) (mean +/- SD) than patients with NCPE (14.5 +/- 4.9 ml/kg; p less than 0.05), despite a higher mean PCWP in the former group (20 +/- 7 mm Hg) than in the latter (12 +/- 6 mm Hg; p less than 0.05). In patients potentially with only a hydrostatic cause of pulmonary edema in study A, regression analysis demonstrated the following: EVLW = 3.2 + 0.30 PCWP (r2 = 0.38; p less than 0.005); and in patients with NCPE, EVLW = 10.9 + 0.304 PCWP (r2 = 0.17; p less than 0.01). In study B the change (delta) in EVLW between the two studies was described as follows: delta EVLW = 0.25 + 0.173 delta PCWP (p less than 0.01) + 0.663 group NCPE (p, not significant) + 0.236 group NCPE X delta PCWP (p less than 0.01). This latter equation indicated that the EVLW content manifested a greater change with concurrent alterations in the PCWP in patients with NCPE than was found in patients with only a hydrostatic influence to EVLW formation. Therefore, NCPE is characterized by a greater measurable thermal green dye EVLW than is observed in CPE at any given PCWP, and the PCWP synergistically influences EVLW accumulation in both CPE and NCPE.     

Prognostic value of extravascular lung water in critically ill patients

OBJECTIVE: Measurement of extravascular lung water (EVLW) as a clinical tool for the assessment of pulmonary function has been found to be more appropriate than oxygenation parameters or radiographic techniques. In this study, we analyzed the prognostic value of EVLW in critically ill patients. DESIGN: Retrospective analysis. SETTING: Operative ICU of a university hospital. MEASUREMENTS AND RESULTS: We retrospectively analyzed 373 critically ill patients (133 female and 240 male patients; age range, 10 to 89 years; mean +/- SD age, 53 +/- 19 years) who were treated in our ICU between 1996 and 2000. All these patients were hemodynamically monitored by the transpulmonary double-indicator (thermo-dye) dilution technique. Each patient received a femoral artery sheath through which a 4F flexible catheter with an integrated thermistor and fiberoptic was advanced into the infradiaphragmatic aorta. EVLW was calculated using a computer system. For each measurement, 15 to 17 mL of cooled 2% indocyanine green were injected central venously. In our results, maximum EVLW was significantly higher in nonsurvivors (n = 186) than in survivors (n = 187) [median, 14.3 mL/kg vs 10.2 mL/kg, respectively; p < 0.001]. In univariate logistic regression models, EVLW (r(2) = 0.024, p = 0.003) at baseline as well as simplified acute physiology score (SAPS) II (r(2) = 0.135, p < 0.0001) and APACHE (acute physiology and chronic health evaluation) II scores (r(2) = 0.050, p < 0.0001) were significant predictors of mortality. If SAPS II and APACHE II scores are combined, r(2) increases to 0.136, but the improvement over SAPS II alone is not significant. The addition of baseline EVLW further increases r(2) to 0.149 (p = 0.021 for the improvement), indicating that EVLW contributes independently to prognosis. CONCLUSION: EVLW correlated well with survival (ie, nonsurvivors had significantly higher EVLW values than survivors) and is an independent predictor of prognosis.     

三七总皂苷对急性肺损伤大鼠血管外肺水的影响及其机制的研究

目的 探讨三七总皂苷(PNS)对急性肺损伤(ALI)大鼠血管外肺水(EVLW)含量及肺泡Ⅱ型上皮细胞钠通道α亚基(αENaC)mRNA和蛋白表达的影响.方法 使用肠缺血1h,再灌注3h建立ALI大鼠模型.48只大鼠随机分为4组(n=12):①单纯手术组,除不夹闭肠系膜上动脉外,余同第3组;②单纯手术+PNS组,除了以PNS代替生理盐水外,余同第1组;③ALI模型组;④ALI模型+PNS组.第2、4组动物再灌注前15 min腹腔注射PNS 100 mg/kg;第1、3组则给予等体积生理盐水代替PNS.再灌注3h后腹主动脉采血进行血气分析,重力法测定血管外肺水指数(EVLWI),逆转录-聚合酶链反应检测αENaC mRNA的表达,Western blotting法测定αENaC蛋白表达.结果 与ALI模型组比较,ALI模型+PNS组大鼠EVLWI显著降低[(27.68±1.31)ml/kg vs (32.57±1.50) ml/kg,P ＜0.01];αENaC mRNA及蛋白表达增强(P值均＜0.05);氧合指数显著增高(P值均＜0.01).结论 PNS能够降低肠缺血-再灌注损伤所致ALI大鼠的EVLW,改善低氧血症,这一作用可能部分是通过抑制αENaC mRNA及蛋白表达下降实现的.     

Usefulness of ultrasound lung comets as a nonradiologic sign of extravascular lung water

The "comet-tail" is an ultrasound sign detectable with ultrasound chest instruments; this sign consists of multiple comet-tails fanning out from the lung surface. They originate from water-thickened interlobular septa and would be ideal for nonradiologic bedside assessment of extravascular lung water. To assess the feasibility and value of ultrasonic comet signs, we studied 121 consecutive hospitalized patients (43 women and 78 men; aged 67 +/- 12 years) admitted to our combined cardiology-pneumology department (including cardiac intensive care unit); the study was conducted with commercially available echocardiographic systems including a portable unit. Transducer frequencies (range 2.5 to 3.5 MHz) were used. In each patient, the right and left chest was scanned by examining predefined locations in multiple intercostal spaces. Examiners blinded to clinical diagnoses noted the presence and numbers of lung comets at each examining site. A patient lung comet score was obtained by summing the number of comets in each of the scanning spaces. Within a few minutes, patients underwent chest x-ray, with specific assessment of extravascular lung water score by 2 pneumologist-radiologists blinded to clinical and echo findings. The chest ultrasound scan was obtained in all patients (feasibility 100%). The imaging time per examination was always <3 minutes. There was a linear correlation between echocardiographic comet score and radiologic lung water score (r = 0.78, p <0.01). Intrapatient variations (n = 15) showed an even stronger correlation between changes in echocardiographic lung comet and radiologic lung water scores (r = 0.89; p <0.01). In 121 consecutive hospitalized patients, we found a linear correlation between echocardiographic comet scores and radiologic extravascular lung water scores. Thus, the comet-tail is a simple, non-time-consuming, and reasonably accurate chest ultrasound sign of extravascular lung water that can be obtained at bedside (also with portable echocardiographic equipment) and is not restricted by cardiac acoustic window limitations.     

Evaluation of the prognostic value of lncRNA UCA1 combined with extravascular lung water index and lung ultrasound score in patients with acute lung injury

Introduction

Acute lung injury (ALI) is a common and rapidly developing critical inflammatory lung disease in clinic. This study investigated the predictive value of lncRNA UCA1, extravascular lung water index (EVLWI), and lung ultrasound score (LUS) in predicting the overall outcome of patients with ALI.

Methods

Patients with ALI were recruited for detecting the content of UCA1, EVLWI, and LUS. All patients were cataloged into the survival group and death group according to the prognosis. The discrepancy of UCA1, EVLWI, and LUS was compared in the two groups. The prognostic significance of UCA1, EVLWI, LUS, and their combination was estimated by logistic regression and the receiver operating characteristic (ROC) curve.

Results

The levels of UCA1, LUS, and EVLWI were elevated in the death group compared with the survival group. The content of UCA1 was positively correlated with LUS scores and EVLWI scores. UCA1, LUS, and EVLWI were independent indicators of predicting the prognosis of patients with ALI. The ROC curve reflected that UCA1, LUS, and EVLWI could forecast the endpoint events of patients with ALI whereas their combined approach had the highest accuracy.

Conclusion

Highly expressed UCA1 is a biomarker in forecasting the outcome of patients with ALI. It had high accuracy in predicting the endpoint of patients with ALI when combined with LUS and EVLWI.     

Measurement of extravascular lung water in infants and children after cardiac surgery

Extravascular lung water (EVLW) was measured in 17 patients with congenital heart disease by the cold-green-dye, double indicator-dilution technique. In 5 control patients, EVLW was 4.7 ± 0.5 ml/kg (111 ± 13 ml/m²) (mean ± standard deviation). Twelve patients were studied immediately after correction of their heart defects. In 6 patients with normal or decreased pulmonary blood flow preoperatively (Group I), EVLW was 6.2 ± 1.9 ml/kg (122 ± 46 ml/m²). This value is not significantly different from that of the control patients. In 6 patients with increased pulmonary blood flow and congestive heart failure preoperatively (Group II), EVLW was 15.7 ± 3.8 ml/kg (270 ± 60 ml/m²), which is significantly different from both control and Group I patients (p < 0.01). There was no correlation of EVLW with pre- or postoperative left atrial pressure, length of cardiopulmonary bypass or deep hypothermic circulatory arrest, postoperative serum protein, albumin, hematocrit or cardiac index. Thus, EVLW in the immediate postoperative period is determined by preoperative pathophysiologic characteristics rather than by intraoperative management, and patients with congestive heart failure resulting from left-to-right shunts have increased EVLW despite normal left atrial pressures.