Lung fluid balance evaluated by the rate of change of extravascular lung water content

1990 ◽  
Vol 34 (5) ◽  
pp. 362-369 ◽  
Author(s):  
C. Frostell ◽  
H. Blomqvist ◽  
C. J. Wickerts ◽  
G. Hedenstierna
Keyword(s):  
Water Content ◽  
Fluid Balance ◽  
Extravascular Lung Water ◽  
Rate Of Change ◽  
Lung Water ◽  
Lung Fluid ◽  
Lung Fluid Balance ◽  
Lung Water Content

Radiographic lung density assessed by computed tomography is associated with extravascular lung water content

2010 ◽  
Vol 54 (8) ◽  
pp. 1018-1026 ◽  
Author(s):  
V. V. KUZKOV ◽  
E. V. SUBOROV ◽  
M. Y. KIROV ◽  
K. WAERHAUG ◽  
R. MORTENSEN ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Water Content ◽  
Extravascular Lung Water ◽  
Lung Water ◽  
Lung Density ◽  
Lung Water Content

scholarly journals Pulmonary Interstitial Matrix and Lung Fluid Balance From Normal to the Acutely Injured Lung

2021 ◽  
Vol 12 ◽  
Author(s):  
Egidio Beretta ◽  
Francesco Romanò ◽  
Giulio Sancini ◽  
James B. Grotberg ◽  
Gary F. Nieman ◽  
...  
Keyword(s):  
Fluid Balance ◽  
Dry Weight ◽  
Inflammatory Factors ◽  
Pressure Gradients ◽  
Lung Water ◽  
Edema Formation ◽  
Water Binding ◽  
Lung Fluid ◽  
Lung Fluid Balance ◽  
Lung Overdistension

This review analyses the mechanisms by which lung fluid balance is strictly controlled in the air-blood barrier (ABB). Relatively large trans-endothelial and trans-epithelial Starling pressure gradients result in a minimal flow across the ABB thanks to low microvascular permeability aided by the macromolecular structure of the interstitial matrix. These edema safety factors are lost when the integrity of the interstitial matrix is damaged. The result is that small Starling pressure gradients, acting on a progressively expanding alveolar barrier with high permeability, generate a high transvascular flow that causes alveolar flooding in minutes. We modeled the trans-endothelial and trans-epithelial Starling pressure gradients under control conditions, as well as under increasing alveolar pressure (Palv) conditions of up to 25 cmH2O. We referred to the wet-to-dry weight (W/D) ratio, a specific index of lung water balance, to be correlated with the functional state of the interstitial structure. W/D averages ∼5 in control and might increase by up to ∼9 in severe edema, corresponding to ∼70% loss in the integrity of the native matrix. Factors buffering edemagenic conditions include: (i) an interstitial capacity for fluid accumulation located in the thick portion of ABB, (ii) the increase in interstitial pressure due to water binding by hyaluronan (the “safety factor” opposing the filtration gradient), and (iii) increased lymphatic flow. Inflammatory factors causing lung tissue damage include those of bacterial/viral and those of sterile nature. Production of reactive oxygen species (ROS) during hypoxia or hyperoxia, or excessive parenchymal stress/strain [lung overdistension caused by patient self-induced lung injury (P-SILI)] can all cause excessive inflammation. We discuss the heterogeneity of intrapulmonary distribution of W/D ratios. A W/D ∼6.5 has been identified as being critical for the transition to severe edema formation. Increasing Palv for W/D > 6.5, both trans-endothelial and trans-epithelial gradients favor filtration leading to alveolar flooding. Neither CT scan nor ultrasound can identify this initial level of lung fluid balance perturbation. A suggestion is put forward to identify a non-invasive tool to detect the earliest stages of perturbation of lung fluid balance before the condition becomes life-threatening.

Assessment of fluid balance in isolated sheep lungs

1985 ◽  
Vol 58 (3) ◽  
pp. 882-891 ◽  
Author(s):  
G. A. Patterson ◽  
W. A. Mitzner ◽  
J. T. Sylvester
Keyword(s):  
Fluid Balance ◽  
Autologous Blood ◽  
Pressure Ratio ◽  
Lymph Flow ◽  
Lung Water ◽  
Lung Weight ◽  
Superior Mediastinum ◽  
Lung Fluid ◽  
Lung Fluid Balance ◽  
Isolated Lung

In this study we demonstrate the validity and utility of an isolated lung preparation developed for the study of pulmonary fluid balance. Lungs of 2- to 3-mo-old sheep were perfused in situ with autologous blood treated with indomethacin (20 micrograms/ml). Lung lymph flow (QL), uncontaminated by systemic lymph, was measured from either the efferent duct of the caudomediastinal lymph node or the thoracic duct in the superior mediastinum. Lung weight change (delta W) was measured as the opposite of the change in weight of the extracorporeal blood reservoir. A unique feature of this experimental model is the ability to assess lung fluid balance from simultaneous measurements of delta W and QL. In addition, hemodynamic and blood gas variables can be tightly controlled. Our results show that changes in QL and the lymph-to-plasma oncotic pressure ratio caused by an increase in microvascular pressure were comparable with those seen previously in intact sheep. When microvascular pressure was returned to control levels, QL fell despite a sustained increase in the amount of extravascular lung water, suggesting compartmentalization of the filtrate and/or effects of intravascular volume on lymph-driving pressure or resistance. Lymph flow was directly proportional to respiratory frequency over the range of 0–30 min-1 when the change in frequency was maintained for periods as long as 30 min. This preparation should prove useful in the study of lung fluid balance, particularly when it is desired to use interventions which are precluded or difficult in intact animals.

Effect of dehydration on interstitial pressures in the isolated dog lung

1989 ◽  
Vol 67 (2) ◽  
pp. 839-845 ◽  
Author(s):  
M. R. Glucksberg ◽  
J. Bhattacharya
Keyword(s):  
Blood Flow ◽  
Water Content ◽  
Extravascular Lung Water ◽  
Base Line ◽  
Inflation Pressure ◽  
Lung Water ◽  
Lung Expansion ◽  
Regional Lung ◽  
Lung Water Content

We have determined the effect of dehydration on regional lung interstitial pressures. We stopped blood flow in the isolated blood-perfused lobe of dog lung at vascular pressure of approximately 4 cmH2O. Then we recorded interstitial pressures by micropuncture at alveolar junctions (Pjct), in perimicrovascular adventitia (Padv), and at the hilum (Phil). After base-line measurements, we ventilated the lobes with dry gas to decrease extravascular lung water content by 14 +/- 5%. In one group (n = 10), at constant inflation pressure of 7 cmH2O, Pjct was 0.2 +/- 0.8 and Padv was -1.5 +/- 0.6 cmH2O. After dehydration the pressures fell to -5.0 +/- 1.0 and -5.3 +/- 1.3 cmH2O, respectively (P less than 0.01), and the junction-to-advential gradient (Pjct-Padv) was abolished. In a second group (n = 6) a combination of dehydration and lung expansion with inflation pressure of 15 cmH2O further decreased Pjct and Padv to -7.3 +/- 0.7 and -7.1 +/- 0.7 cmH2O, respectively. Phil followed changes in Padv. Interstitial compliance was 0.6 at the junctions, 0.8 in adventitia, and 0.9 ml.cmH2O-1.100 g-1 wet lung at the hilum. We conclude, that perialveolar interstitial pressures may provide an important mechanism for prevention of lung dehydration.

Interactions between permeability and hydrostatic pressure in perfused dogs' lungs

1981 ◽  
Vol 50 (4) ◽  
pp. 905-911 ◽  
Author(s):  
G. J. Huchon ◽  
P. C. Hopewell ◽  
J. F. Murray
Keyword(s):  
Oleic Acid ◽  
Hydrostatic Pressure ◽  
Water Content ◽  
Pulmonary Vasculature ◽  
Lung Water ◽  
Lung Fluid ◽  
Lung Slice ◽  
Lung Water Content ◽  
Measured Water

To evaluate interactions between increased permeability of the pulmonary vasculature and increased hydrostatic pressure on lung fluid flux, we measured water and blood contents of five equally thick slices of in situ perfused dogs' lungs that had been vertically suspended and, after experimental manipulations, rapidly frozen. Measurements were made under four sets of conditions (4 dogs each): 1) control; 2) increased left atrial pressure (Pla), 25 cmH2O relative to the bottom of the lung; 3) oleic acid; and 4) oleic acid and increased Pla. Significant interactions on lung water content were found between 1) oleic acid and increased Pla (P less than 0.005) and 2) oleic acid and height of the slice of lung (P less than 0.003). Blood content was significantly affected by interactions between 1) oleic acid and height of the lung slice (P less than 0.001) and 2) increased Pla and height of the lung slice (P less than 0.001). We conclude that there are significant interactions between increased permeability and hydrostatic pressure that affect regional lung water content and intrapulmonary distribution of blood.

Lung fluid balance in lambs before and after birth

1982 ◽  
Vol 53 (4) ◽  
pp. 992-1004 ◽  
Author(s):  
R. D. Bland ◽  
T. N. Hansen ◽  
C. M. Haberkern ◽  
M. A. Bressack ◽  
T. A. Hazinski ◽  
...  
Keyword(s):  
Fluid Balance ◽  
Endothelial Permeability ◽  
Lymph Flow ◽  
Lung Water ◽  
Fluid Exchange ◽  
Lung Fluid ◽  
Lung Fluid Balance ◽  
Before And After ◽  
Lung Lymph ◽  
Lung Lymph Flow

To study lung fluid balance before and after birth, we measured lung lymph flow and concentrations of protein in lymph and plasma of 22 unanesthetized fetal lambs and compared results with previous studies done on 26 newborn lambs, 1–2 wk old. Lymph flow, relative to lung mass, was less in fetuses than in newborns; lymph protein clearance was not significantly different. Less lymph flow before birth probably reflects less available surface area for fluid exchange in microcirculation of fetal lungs, compared with newborn lungs, with no difference in endothelial permeability to protein. Extravascular lung water, measured gravimetrically for 24 fetuses (10 without labor, nine in labor, five 6 h after vaginal birth), decreased by 45% (15 +/- 2 g/kg body wt) before birth and by an additional 38% (6 +/- 1 g/kg) after birth. In five lambs killed after birth, we measured lung lymph flow before and during labor and for 6 h after breathing began. Lymph flow was unaffected by labor but increased transiently after birth, accounting for 11% of the liquid removed from lungs postnatally. Liquid clearance studies performed in eight anesthetized 3-wk-old lambs confirmed the observation that lung lymphatics drain only a small fraction of liquid in potential air spaces. Most of that liquid probably leaves the lungs directly through pulmonary circulation.

Measurement of extravascular lung water in the ICU

2016 ◽  
Author(s):  
Danny F. McAuley ◽  
Thelma Rose Craig
Keyword(s):  
Pulmonary Oedema ◽  
Extravascular Lung Water ◽  
Endothelial Damage ◽  
Lung Water ◽  
Alveolar Epithelial ◽  
Lung Fluid ◽  
Lung Fluid Balance ◽  
Pulmonary Capillary ◽  
Transpulmonary Thermodilution Technique ◽  
Fluid Formation

The accumulation of fluid in the interstitium and alveolar space is known as extravascular lung water (EVLW). EVLW is associated with increased morbidity and mortality in critically ill patients and is elevated in patients with cardiogenic pulmonary oedema, acute lung injury (ALI), and the acute respiratory distress syndrome (ARDS). Pulmonary oedema is a consequence of increased pulmonary capillary hydrostatic pressure and/or an increased capillary permeability. The quantity of pulmonary oedema fluid is dependent on the balance of fluid formation and clearance, and this contributes to the overall dynamic net lung fluid balance. Measurement of EVLW is therefore an indirect surrogate measurement of the alveolar epithelial and endothelial damage in ALI/ARDS. The single indicator transpulmonary thermodilution technique is an available bedside technique to measure EVLW.

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