超声评估血管外肺水

血管外肺水(EVLW)是评估肺水肿的重要指标,与死亡率独立相关,积极治疗可改善患者预后.CT和MRI可准确评估肺水肿,但不适用于实时监测;而单次热稀释需要重复校准,易出错.由于空气的高声阻抗,传统上认为肺部不适于超声检查.超声B线是识别EVLW及观察其动态变化的灵敏方法,伴随研究的深入,超声越来越多地用于评估EVLW,...     

肺部超声评估血管外肺水研究进展

正常情况下,肺内充满空气,而超声波对空气有强烈的反射作用,因而长期以来肺部是超声检查的盲区。然而病理情况下,如心源性肺水肿时流体静压增高,以及急性呼吸窘迫综合征（acute respiratory distress syndrome,ARDS）时内皮细胞和上皮细胞渗透性增加时,血管外肺水（extravascular lung water,EVLW）增多。此时超声影像可观察到特征性变化。     

血管外肺水指数和肺毛细血管渗透性指数在肺水肿诊断中的意义

目的 探讨血管外肺水指数(EVLWI)、肺毛细血管渗透性指数(PVPI)在诊断及动态监测肺水肿时的临床价值.方法 选择40例行脉搏轮廓曲线连续心排血量(PiCCO)监测的肺水肿患者,根据入院时的病史、症状、体征、辅助检查及血流动力学变化将患者分为急性心源性肺水肿(ACPE)组(15例)和急性呼吸窘迫综合征(ARDS)组(25例).记录入院时各指标并行相关性分析,再于置入气管插管0、24和72 h 时记录存活与死亡患者EVLWI、胸内血容量指数(ITBVI),并计算PVPI值.结果 ①置管0 h 时ARDS组PVPI显著高于ACPE组(P＜0.01).②相关性分析显示:ACPE组PVPI与氧合指数(PaO2/FiO2)、急性生理学与慢性健康状况评分系统Ⅱ(APACHEⅡ)评分、EVLWI、ITBVI、中心静脉压(CVP)均无显著相关性(P均＞0.05);EVLWI与PaO2/FiO2(r=-0.672,P＜0.01)、APACHEⅡ评分(r=0.412,P＜0.05)、ITBVI(r=0.636,P＜0.05)有一定相关性.ARDS组PVPI与EVLWI(r=0.904 P＜0.01)、PaO2/FiO2(r=-0.554,P＜0.01)、APACHEⅡ评分(r=0.390,P＜0.05)均显著相关;EVLWI与PaO2/FiO2(r=-0.602,P＜0.01)、APACHEⅡ评分(r=0.457,P＜0.05)、PVPI(r=0.904,P＜0.01)具有一定相关性.③绘制PVPI受试者工作特征曲线(ROC曲线),曲线下面积(AUC)为0.956±0.019(P＜0.01);选取PVPI的截断点为2.23时,其敏感性为92.0%,特异性为93.3%.④根据预后,将患者分为存活组及死亡组,ACPE和ARDS存活组的EVLWI均逐渐下降(P＜0.05和P＜0.01);ACPE死亡组PVPI有增高趋势(P＜0.01).结论 将EVLWI、PVPI(截断点2.23)用于鉴别静水压性和通透性肺水肿,以及评估病情严重程度和预后有一定的临床意义.     

严重创伤患者血管外肺水的临床研究

目的:研究严重创伤患者血管外肺水(EVLW)的变化规律,以指导液体复苏治疗.方法:根据创伤严重程度评分(ISS)选取42例严重创伤患者,均予以接PICCO临护仪测得EVLW,并同步监测氧合指数(PaO2/FiO2)和各时间段内的液体进出量;描记EVLW及氧合指数变化趋势图,分析各数据.结果:严重创伤患者在入ICU后12 h EVLW超过正常,2 d时达高峰,以后逐渐下降,4～5 d后恢复正常,氧合指数变化趋势与EVLW呈负相关,但下降得更早;42例患者伤后入ICU前有27例行积极正压复苏,15例行限制液体低压复苏,两组EVLW在入ICU后6 h、12 h、24 h及第2 d均有显著性差异(P<0.05);EVLW持续增高者与先增高后下降者病死率差异有显著性(P=0.015,Fisher·确切检验法).结论:严重创伤患者EVLW呈早期增高,2 d达高峰,4～5 d后逐渐降至正常的变化规律,持续增高的 EVLW可增加严重创伤患者的病死率;伤后早期正压液体复苏增加了其EVLW,有必要对其在液体治疗中监测EVLW,根据EVLW的变化实施液体复苏.     

血管外肺水监测的方法及其临床意义

呼吸困难、咳嗽、咳血性痰、双肺湿性啰音是肺水肿的主要临床症状和体征,但这些临床特征的出现往往提示肺水肿已发展到严重阶段。血管外肺水(extravascular lung water,EVLW)概念的提出可利于     

急性颅脑疾病患者血管外肺水指数的分布状况分析

目的 探讨急性颅脑疾病患者血管外肺水指数(EVLWI)的分布状况.方法 本研究回顾性调查了2009年1月至2014年12月共71例由于急性颅脑疾病而收住北京大学首钢医院ICU的病历资料,对所有研究对象于发病6 h内置入连续心输出量(PICCO)装置监测血流动力学指标.收集研究对象年龄、性别、急性生理和慢性健康Ⅱ(APA...     

ALI/ARDS早期血管外肺水影响因素研究进展

血管外肺水(extravascular lung water,EVLW)增加是急性肺损伤(ALI)和急性呼吸窘迫综合征(ARDS)的重要病理生理改变之一。研究ALI/ARDS早期EVLW变化及其影响因素,对于了解ALI/ARDS早期病理特征及指导临床治疗有重要意义。本文介绍ALI/ARDS早期EVLW的变化情况及主要影响因素,如上皮钠通道、呼吸末正压通气、糖皮质激素、心输出量、肺动脉压、一氧化氮等的相关研究进展。     

腹腔内压升高对血管外肺水的影响

目的 观察不同程度腹内压(TAP)对血管外肺水(EVLW)的影响.方法 选取2009-2011年入住保定市第一医院ICU,出现腹内压升高的患者129例,分为三组:IAP≤10 cm H2O组;10 cm H2O20 cm H2O组.测定不同TAP下EVLW含量.结果 IAP>20 cm H2O组所测得EVLW明显高于其他两组,TAP升高的时间越长,EVLW值就越高,差异均有统计学意义.结论 随着TAP的升高,EVLW含量有明显增加.说明IAP对EVLW是有影响的.     

血管外肺水的临床应用

血管外肺水（extravascular lung water,EVLW）即肺血管外的液体,包括细胞内液、间质液和肺泡液。后两者是导致临床上EVLW增多的主要成分。肺血管内静水压、肺间质静水压、肺毛细血管内胶体渗透压、肺间质胶体渗透压、     

严重脓毒症患者血管外肺水的监测价值与研究现状

脓毒症所致的多器官功能障碍中,肺脏是最易受损伤的靶器官。脓毒症相关性ARDS/ALI的发病机制复杂,迄今为止其发病机制尚未完全阐明〔1〕。其基本病理生理改变是肺泡-毛细血管屏障功能障碍所致通透性升高,表现为肺血管内液体渗出增加形成血管外肺水（extravascular lung water,EVLW）的聚集。EVLW增加引起的严重通     

Clinical measurement of extravascular lung water

The thermal-dye technique for the measurement of ELW is available for clinical and experimental use. This method is safe and can be performed serially in an individual patient. Although it is invasive, it requires only a central venous catheter and an arterial catheter, which are often already in place for routine hemodynamic monitoring and management. The procedure is accurate under a variety of conditions. Two obstacles argue against its routine application. First, the reliability of this approach appears to be seriously compromised when there are areas of edematous lung with poor blood perfusion. This includes aspiration and perhaps other forms of acute lung injury. Second, it remains to be demonstrated how useful routine measurements of ETVL, even if accurate, are in clinical management. However, regardless of the accuracy of the various methods for determination of ELW, the process of their development has significantly enhanced our knowledge of pulmonary edema formation and fluid distribution. We are at a transition point of soon being able to determine ELW easily. Techniques of reducing ELW can now be assessed directly in patients with pulmonary edema. As these therapies are developed and understood, the demand for the measurement of ELW will become a greater part of clinical medicine, and may stimulate further refinement of methods for quantitating lung water.     

Monitoring of extravascular lung water in patients with severe sepsis

The key objective of the case study was the possibility to monitor the extravascular lung water (EVLW) in severe cases. Twelve mechanically ventilated patients with severe sepsis complicated by septic shock and by an acute lung injury (ALI) were involved in the prospective study. The measurements, performed on days 1 and 3 after the onset of sepsis, comprised hemodynamics, EVLW as assessed by Pulsion PiCCO method, blood gases and severity scores. The EVLW correlated significantly with lung injury score (r = 0.46), oxygenation (r = -0.46) and with pulmonary compliance (r = -0.58) versus the central venous pressure. The EVLW and lung injury scores were found to be essentially higher in non-survivors on day 3. The clinical situations, described in the present article, are indicative of a potential EVLW value applicable to sepsis treatment. Finally, the monitoring of EVLW is a useful tool in the purpose-oriented therapy of sepsis-induced ALI; moreover, the method has an important prognostic value.     

Evaluation of extravascular lung water by single thermal indicator

Much attention has been directed to developing early therapy that might prevent or ameliorate incipient adult respiratory distress syndrome (ARDS) before respiratory failure ensues. The relationship between increased extravascular lung water (EVLW) and pulmonary microvascular pressure has been used by numerous investigators to confirm alterations in the permeability of the alveolar capillary membrane. In the present study, EVLW was measured in 40 critically ill patients by an indicator dilution technique utilizing thermal indicator alone. Injection of cold saline distinguished intravascular and extravascular compartments with a sensitivity similar to that of the thermal-dye double-indicator dilution technique but without the withdrawal of blood, dye densitometry, or the preparation of special injectate. Both absolute volumes and volume changes over time measured by the single thermal indicator method compared favorably (p less than .001) to EVLW values determined simultaneously by the conventional thermal-dye double-indicator dilution technique. These results suggest that the single thermal indicator technique may help identify the earliest phase of ARDS when fluid is starting to accumulate in the lung interstitium.     

Validation of extravascular lung water measurement by single transpulmonary thermodilution: human autopsy study

Introduction

Gravimetric validation of single-indicator extravascular lung water (EVLW) and normal EVLW values has not been well studied in humans thus far. The aims of this study were (1) to validate the accuracy of EVLW measurement by single transpulmonary thermodilution with postmortem lung weight measurement in humans and (2) to define the statistically normal EVLW values.

Methods

We evaluated the correlation between pre-mortem EVLW value by single transpulmonary thermodilution and post-mortem lung weight from 30 consecutive autopsies completed within 48 hours following the final thermodilution measurement. A linear regression equation for the correlation was calculated. In order to clarify the normal lung weight value by statistical analysis, we conducted a literature search and obtained the normal reference ranges for post-mortem lung weight. These values were substituted into the equation for the correlation between EVLW and lung weight to estimate the normal EVLW values.

Results

EVLW determined using transpulmonary single thermodilution correlated closely with post-mortem lung weight (r = 0.904, P < 0.001). A linear regression equation was calculated: EVLW (mL) = 0.56 × lung weight (g) - 58.0. The normal EVLW values indexed by predicted body weight were approximately 7.4 ± 3.3 mL/kg (7.5 ± 3.3 mL/kg for males and 7.3 ± 3.3 mL/kg for females).

Conclusions

A definite correlation exists between EVLW measured by the single-indicator transpulmonary thermodilution technique and post-mortem lung weight in humans. The normal EVLW value is approximately 7.4 ± 3.3 mL/kg.

Trial registration

UMIN000002780.