血管外肺水的定量评估

1、血管外肺水的定量评估安徽省立医院重症医学科杨田军血管外肺水的定义 Pulmonary edema is characterized by excess accumulation of fluid in the extravascular space of the lungs, namely extravascular lung water (EVLW). 肺水肿是指过多的液体聚集于肺血管外，也就是血管外肺水 The pathological condition of pulmonary edema develops by two mechanisms: An increase in the p

2、ulmonary capillary hydrostatic pressure (hydrostatic or cardiogenic pulmonary edema) and an increase in pulmonary capillary permeability (acute respiratory distress syndrome ARDS). However, it is often difficult to discriminate between edema caused by increased hydrostatic pressure in the course of

3、cardiac disease, or by increased permeability associated with ARDS 肺水肿的发生机制有两种：1.肺毛细血管的静水压增高（静水压或者心源性肺水肿）。2.毛细血管通透性增高（ARDS）。然而临床上有时很难区别这两种病因。前者进入肺间质和肺泡的主要是水分，而后者除了水分外还有大量蛋白等组织成分AECC和柏林标准诊断ARDS存在的问题 对影像学的评估主要是主观的，缺少客观指标 基础有慢性心脏疾病的患者，在罹患ARDS时会合并心脏功能不全，即使既往五心脏疾病，脓毒症本身等因素本身也会导致心脏功能受损 对病理与临床关系的研究显示，临床诊断为

4、ARDS是患者，仅有一半左右表现为ARDS的特征病理学变化：弥漫性肺泡损伤Am J Respir Crit Care Med. 2013 ,187(7):761-7. If we are to require positive pressure ventilation in our definition, why not consider lung water is it not time to move forward？ If not EVLW then perhaps deadspace fraction, or the distribution of injury and/or lung

5、 weight by Cat Scan, or a direct measure of permeability some more direct measure of injury specifi c to ARDS.Conclusions: A definite correlation exists between EVLW measured by the single-indicator transpulmonarythermodilution technique and post-mortem lung weight in humansTagami et al. Critical Ca

6、re 2010, 14:R162Crit Care Med. 2013 Sep;41(9):2144-50.EVLWI与ARDS发病前状态及ARDS的关系Annual update in intensive care and emergenct medicine 2014,p 258弹丸注射 肺PiCCO 导管 如：股动脉 经肺热稀释技术需要在中心静脉注射冷盐水( 8C)或室温盐水( 24C)A. 热稀释参数左心右心RAPBVEVLWLALVEVLWRV11全心舒张末期容积（Global Enddiastolic Volume，GEDV）是舒张末时心脏4个腔室的容积之和全心舒张末期容积PTVR

7、AEDVLAEDVLVEDVRVEDVGEDVGEDV = ITTV - PTVITTV GEDV 是ITTV与PTV之差12血管外肺水EVLWEVLWRAEDVRVEDVLAEDVLVEDVPTVEVLWITBVITTVRAEDVRVEDVLAEDVLVEDVPBV 血管外肺水（Extravascular Lung Water，EVLW）反映肺间质内含有的水量，通过ITTV与ITBV之差得到血管外肺水与血管外肺水指数 单纯讨论血管外肺水无意义，必须评估血管外肺水指数 血管外肺水指数的计算方法为：血管外肺水/体重 此体重为哪种体重？实际体重？预计体重？Crit Care Med. 2008 J

8、une ; 36(6): 18031809Crit Care Med. 2008 Jan;36(1):69-73.Crit Care Med. 2008 Jan;36(1):69-73.预计体重的计算公式 The PBW is calculated as follows: men, PBW (kg) = 50 + 0.91 (height in centimeters -152.4); women, PBW (kg) = 45.5 + 0.91 (height in centimeters- 152.4.Crit Care Med. 2012 March ; 40(3): 847854Crit

9、 Care Med. 2012 March ; 40(3): 847854问题In the Berlin definition, the measurement of EVLW was considered but not included in the current criteria. The authors stated that “EVLW does not distinguish between hydrostatic and inflammatory pulmonary edema”, and for this reason it was not included21肺血管通透性指

10、数肺血管通透性指数（Pulmonary Vascular Permeability Index，PVPI）是血管外肺水（EVLW）与肺血容积（PBV），反映了肺水肿的类型Pulmonarv Blood Volume静水压肺水肿通透性肺水肿 PVPI =PBVEVLW正常升高升高PVPI =PBVEVLW升高升高正常 PVPI =PBVEVLW正常正常正常PBVPBVPBV正常Extra Vascular Lung WaterAnnual update in intensive care and emergenct medicine 2014,p 259Kushimoto et al. Crit

11、ical Care 2012, 16:R232Annual update in intensive care and emergenct medicine 2014,p 263Examples: Interpretation of EVLW and PVPI Values A patient admitted 2 days earlier with bacterial pneumonia and bilateral consolidations on a CT scan was ventilated with an FiO2 of 60%, a PEEP of 10 cmH2 O, the P

12、o2 is 70mmHg Diagnoses:Severe pneumonia？ Moderate to severe ARDS？He had an EVLW of 17ml/kg, and a PVPI of 1.5Examples: Interpretation of EVLW and PVPI Values Early aggressive intervention, in addition to lung-protective ventilation, may be required. On the other hand, despite a 2-day history of seps

13、is with fluid overload, white lungs on portable radiograph, and ventilation with an FiO2 of 60% and a PEEP level of 10 cmH2 O, an EVLW of 8ml/kg and a PVPI of 1.0 could indicate clinical conditions other than pulmonary edema,Examples: Interpretation of EVLW and PVPI Values He accepted lung CT scan, the result revealed atelectasis Bronchoscopy was prescribed for him. 2 days lat