Edema clearance in isolated sheep lungs

1993 ◽  
Vol 74 (1) ◽  
pp. 126-132 ◽  
Author(s):  
D. B. Pearse ◽  
E. M. Wagner ◽  
J. T. Sylvester

Edema may be cleared from the lung by lymphatic drainage, transudation across the visceral pleural, vascular reabsorption, and movement into the mediastinum. To determine the quantity and mechanisms of edema clearance associated with spontaneous edema formation in isolated sheep lungs, we perfused six lungs for 180 min with blood (100 ml.kg-1.min-1) at subatmospheric left atrial pressure (Pla) from a weighed reservoir. In six other lungs, Pla was increased to 20 mmHg at 30–75 min to further augment edema. Fluid drainage from the lung was fractionated into blood and water components by serial measurements of drainage and perfusate hematocrit. Changes in weight of circulating intravascular blood and extravascular lung water (EVLW) were also directly measured by dye dilution and standard gravimetric techniques, respectively. From these measurements, we calculated that 3.04 +/- 0.53 g/g blood-free dry lung of water filtered into the extravascular space during perfusion. Of this amount, 42% was reabsorbed into the pulmonary vasculature; 18% drained from the lung via lymphatics, visceral pleura, and mediastinum; and 40% was retained in the lung. Compared with low Pla lungs, transient elevation of Pla increased lung hemorrhage and the final change in reservoir weight, but the quantity and clearance of cumulative filtered water and the final values of EVLW and wet-to-dry weight ratio (WW/DW) were not altered. These results suggest that 1) significant edema clearance occurred in isolated sheep lungs, primarily by vascular reabsorption, and 2) measurements of EVLW and WW/DW under-estimated injury in the presence of lung hemorrhage and significant edema clearance.

1981 ◽  
Vol 50 (1) ◽  
pp. 102-106 ◽  
Author(s):  
P. S. Barie ◽  
T. S. Hakim ◽  
A. B. Malik

We determined the effect of pulmonary hypoperfusion on extravascular water accumulation in anesthetized dogs by occluding the left pulmonary artery for 3 h and then reperfusing it for 24 h. The lung was reperfused either at normal left atrial pressure (Pla) or during increased Pla induced by a left atrial balloon. In each case the extravascular water content-to-bloodless dry weight ratio (W/D) of the left lung was compared with that of the right lung. The W/D of the left lung of 3.26 +/- 0.49 ml/g was not significantly different from the value of 2.87 +/- 0.37 for the right lung after the reperfusion at normal Pla. However, the W/D of the left lung of 5.10 +/- 0.38 ml/g was greater (P less than 0.05) than the value of 4.42 +/- 0.34 for the right lung after reperfusion at Pla of 25 Torr. This difference could not be prevented by pretreatment with heparin, suggesting that the increase in lung water content was not due to activation of intravascular coagulation secondary to stasis occurring during the occlusion. Because the left lung was more edematous than the right one, even though both lungs had been subjected to the same increase in Pla, the results suggest that a period of pulmonary hypoperfusion causes an increase in the interstitial protein concentration.


1986 ◽  
Vol 71 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Stanley Braude ◽  
David Royston

1. The effect in the rat of salbutamol infusion (1 μg min−1 kg−1) on acid-induced lung injury has been determined. Severity of lung injury was assessed by two techniques: the pulmonary clearance of 99mTc-diethylenetriaminepenta-acetate (99mTc-DTPA) and the lung wet/dry weight ratio, giving indices of alveolar epithelial permeability and transendothelial water filtration respectively. 2. Mean half-time of clearance of 99mTc-DTPA was increased significantly in rats who had intratracheal acid-induced injury and control (saline) intravenous infusion (19.4 ± 2.6 min) compared with non-acid-treated rats (98.1 ± 7.2) (P < 0.0001). However, those animals who had intratracheal acid injury and subsequent salbutamol intravenous infusion had significantly faster clearance (11.5 ± 1.9) than the acid and control infusion group (P < 0.05). 3. Gravimetric lung water in the acid-only rats (expressed as wet/dry weight ratio) was increased significantly (6.4 ± 0.3) compared with the non-acid-treated controls (5.4 ± 0.2) (P < 0.01). Acid-treated rats who had salbutamol infused had dramatically increased lung water (10.0 ± 0.6) (P < 0.001 vs acid and control infusion). 4. Intravenous salbutamol infusion itself produced no significant difference in the results for both techniques, compared with the non-acid-treated time-course controls. 5. Infused salbutamol accentuates acid-induced lung injury in the rat. Possible factors responsible for these findings include β2-adrenergic agonist mediated inhibition of hypoxic pulmonary vasoconstriction (HPV) and a predominant β1-adrenergic agonist inotropic effect of salbutamol with resultant rise in pulmonary artery pressure.


1986 ◽  
Vol 61 (6) ◽  
pp. 2156-2161 ◽  
Author(s):  
A. B. Gorin ◽  
G. Mendiondo

We assessed pulmonary endothelial and epithelial permeability and lung lymph flow in nine adult sheep under base-line conditions and after resuscitation from profound hemorrhagic shock. Animals were mechanically ventilated and maintained on 1% halothane anesthesia while aortic pressure was held at 40 Torr for 3 h. Systemic heparin was not used. After reinfusion of shed blood, sheep recovered from anesthesia and we measured lung lymph flow (QL), lymph-to-plasma concentration ratio for proteins, and time taken to reach half-equilibrium concentration of intravenous tracer albumin in lymph (t1/2). Twenty-four hours after bolus injection of radio-albumin we lavaged subsegments of the right upper lobe and determined fractional equilibration of the tracer in the alveolar luminal-lining layer. In each sheep we had measured these parameters 7 days earlier under base-line conditions. Animals were killed, and the lungs were used for gravimetric determination of extravascular lung water (gravimetric extravascular lung water-to-dry weight ratio) 24 h after resuscitation from shock. Pulmonary endothelial injury after resuscitation was evidenced by marked increase in QL, without fall in lymph-to-plasma ratio. Time taken to reach half-equilibrium concentration fell from 169 +/- 47 (SD) min in base-line studies to 53 +/- 33 min after shock. There was no evidence of lung epithelial injury. Gravimetric extravascular lung water-to-dry weight ratio was significantly increased in these animals killed 24 h after resuscitation (4.94 +/- 0.29) compared with values in our laboratory controls (4.13 +/- 0.09, mean +/- SD). These data demonstrate a loss of lung endothelial integrity in sheep after resuscitation from profound hemorrhagic shock.


1987 ◽  
Vol 63 (5) ◽  
pp. 1705-1710
Author(s):  
T. Horie ◽  
T. Izumi ◽  
K. Hodaka ◽  
T. Akashiba ◽  
Y. Hosokawa ◽  
...  

Effects of tidal volume (VT), end-expiratory pressure (EEP), and environmental temperature (Tenv) on elastic recoil force (Pel) and edema formation were examined in open-chest anesthetized rabbits. Sixty-two rabbits in four groups were ventilated for 3 h with VT of either 10 or 25 ml/kg body wt, EEP of 0 or 2 cmH2O, and Tenv of 18 or 35 degrees C. After ventilation, Pel at 80% of total lung capacity (P80) was significantly increased when ventilation was performed with the combination of large VT, 0 EEP, and low Tenv. This change was prevented by altering any one of the three conditions, e.g., small VT, positive EEP, or high Tenv. Similarly, elevation of minimum surface tension and reduction of surface activity index of lavages from excised lungs after ventilation were observed only when increased P80 was noted. Additionally, the increase of P80 was well correlated with increment of wet weight-to-dry weight ratio and degree of perivascular cuffing and alveolar edema formation of excised lungs. These results indicate that elevation of Pel after high tidal ventilation in open-chest animals in vivo was influenced by level of EEP and Tenv and that the degree of edema formation was closely related to the increase of Pel. The increased Pel is presumably primary and causes fluid accumulation.


1977 ◽  
Vol 42 (4) ◽  
pp. 624-629 ◽  
Author(s):  
P. D. Snashall ◽  
W. J. Weidner ◽  
N. C. Staub

We have compared extravascular lung water after extracellular fluid volume expansion with that predicted from lung sucrose space measured in control dogs. In control lungs mean extravascular water:dry weight ratio was 3.81 +/- 0.16 (SD) (n = 5) and extravascular sucrose space/dry weight was 1.79 +/- 0.45 (n = 4). After acute expansion of extracellular fluid volume by 10% of body weight mean extravascular water:dry lung weight was 4.17 +/- 0.27 (m = 5), less than half the predicted increase to 4.63 +/- 0.19, suggesting some degree of protection. After 20% (n = 4), 30% (n = 2), and 40% (n = 1) expansion, no protection was demonstrated and there was considerable scatter of lung water at each infusion volume. When volume expansion increased pulmonary capillary intravascular forces (due to decreased protein osmotic pressure and increased hydrostatic pressure) by more than 20 cmH2O there was a linear increase in extravascular lung water with increasing intravascular forces. Three dogs did not conform to this relationship and had disproportionately large increases in lung water, possibly due to alveolar flooding.


1995 ◽  
Vol 78 (5) ◽  
pp. 1635-1641 ◽  
Author(s):  
S. Tasaka ◽  
A. Ishizaka ◽  
T. Urano ◽  
K. Sayama ◽  
F. Sakamaki ◽  
...  

Hyperoxic lung injury is attributable to oxygen radicals produced under hyperoxic conditions. The 21-aminosteroid (AS), U-74389G, is a potent antioxidant. We examined the effect of U-74389G on lung injury in guinea pigs during exposure to 90% O2 for 48 h. We injected either vehicle or 10 mg/kg of U-74389G 30 min before the O2 exposure and injected the same dose 12, 24, and 36 h later. We performed two series of experiments after exposure. In the first series, we measured the clearance rate of 99mTc-labeled dialdehyde starch (DAS) from the lungs as an index of pulmonary epithelial damage in three experimental groups consisting of 1) control (n = 6) O2 alone (n = 6), and 3) O2 + AS (n = 6). In the second series, pulmonary endothelial injury was estimated by using 28 guinea pigs divided into four experimental groups consisting of 1) control (n = 8), 2) AS alone (n = 5), 3) O2 alone (n = 6), and 4) O2 + AS (n = 9). In the second series, we measured the wet-to-dry weight ratio (W/D) as an index of lung water and the concentration ratio of 125I-labeled albumin in lung tissue and bronchoalveolar lavage (BAL) fluid compared with plasma (T/P and BAL/P, respectively) as indexes of pulmonary endothelial damage. Cell accumulation in BAL fluid and lung tissue samples was also assessed in the second series.(ABSTRACT TRUNCATED AT 250 WORDS)


2004 ◽  
Vol 286 (2) ◽  
pp. H693-H700 ◽  
Author(s):  
Jeffrey M. Dodd-o ◽  
Laura E. Welsh ◽  
Jorge D. Salazar ◽  
Peter L. Walinsky ◽  
Eric A. Peck ◽  
...  

Cardiovascular surgery requiring cardiopulmonary bypass (CPB) is frequently complicated by postoperative lung injury. Bronchial artery (BA) blood flow has been hypothesized to attenuate this injury. The purpose of the present study was to determine the effect of BA blood flow on CPB-induced lung injury in anesthetized pigs. In eight pigs (BA ligated) the BA was ligated, whereas in six pigs (BA patent) the BA was identified but left intact. Warm (37°C) CPB was then performed in all pigs with complete occlusion of the pulmonary artery and deflated lungs to maximize lung injury. BA ligation significantly exacerbated nearly all aspects of pulmonary function beginning at 5 min post-CPB. At 25 min, BA-ligated pigs had a lower arterial Po2at a fraction of inspired oxygen of 1.0 (52 ± 5 vs. 312 ± 58 mmHg) and greater peak tracheal pressure (39 ± 6 vs. 15 ± 4 mmHg), pulmonary vascular resistance (11 ± 1 vs. 6 ± 1 mmHg·l–1·min), plasma TNF-α (1.2 ± 0.60 vs. 0.59 ± 0.092 ng/ml), extravascular lung water (11.7 ± 1.2 vs. 7.7 ± 0.5 ml/g blood-free dry weight), and pulmonary vascular protein permeability, as assessed by a decreased reflection coefficient for albumin (σalb; 0.53 ± 0.1 vs. 0.82 ± 0.05). There was a negative correlation ( R = 0.95, P < 0.001) between σalband the 25-min plasma TNF-α concentration. These results suggest that a severe decrease in BA blood flow during and after warm CPB causes increased pulmonary vascular permeability, edema formation, cytokine production, and severe arterial hypoxemia secondary to intrapulmonary shunt.


1987 ◽  
Vol 62 (4) ◽  
pp. 1363-1367 ◽  
Author(s):  
R. P. Fairman ◽  
C. N. Sessler ◽  
M. Bierman ◽  
F. L. Glauser

The polycation protamine sulfate increases microvascular permeability in the kidney by reducing glomerular charge. We have exposed the pulmonary vasculature to protamine sulfate to determine whether electrical charges play a role in protein permeability in lung vascular beds. In anephric rats, protamine sulfate increased hematocrit approximately 25%. With protamine sulfate doses of 0.08 and 0.04 mg/g body wt, lung blood-free wet-to-dry weight ratios were increased (5.24 +/- 0.8 and 4.89 +/- 0.7) compared with control (3.85 +/- 0.3) (P less than 0.05). In isolated, ventilated, and perfused lungs 0.04 mg/g body wt protamine sulfate increased pulmonary arterial pressure from 5.2 +/- 1.4 to 16.3 +/- 3.9 mmHg (P less than 0.01). These lungs gained weight and lung wet-to-dry weight ratios were significantly increased (15.33 +/- 4.26 compared with 6.04 +/- 0.24 for control lungs). Poly-L-lysine, another polycation, also caused significant increases in pulmonary arterial pressure, lung weight, and lung wet-to-dry weight ratios. The addition of diphenhydramine to the perfusate 10 min before the addition of protamine sulfate did not prevent these changes. Heparin (90 U/mg protamine sulfate) reversed the abnormalities. Pulmonary arterial pressure (7.0 +/- 1.1 mmHg) was not significantly different from the control value, lung weight did not increase, and the lung wet-to-dry weight ratio was 6.24 +/- 0.23 (P greater than 0.05). We conclude that polycations have a significant effect on pulmonary vascular resistance and perhaps on permeability.


1987 ◽  
Vol 63 (3) ◽  
pp. 907-911 ◽  
Author(s):  
T. Prien ◽  
L. D. Traber ◽  
D. N. Herndon ◽  
J. C. Stothert ◽  
H. J. Lubbesmeyer ◽  
...  

Despite experimental evidence for an increase in extravascular lung water (EVLW) after inhalation injury, thermal-dye estimations of EVLW, extravascular thermal volume (EVTV), have repeatedly failed to demonstrate its presence in patients. This situation was evaluated in a sheep model. Under halothane anesthesia one lung was insufflated with cotton smoke and the other with air. EVTV values were 8.4 +/- 0.48 ml/kg at base line and were not elevated at 24 h after smoke inhalation (8.3 +/- 0.45 ml/kg; means +/- SE). Gravimetric analysis 24 h after smoke inhalation showed the development of edema in smoke-exposed lungs. The blood-free wet weight-to-dry weight ratio of the smoke-exposed lungs (5.4 +/- 0.32) was significantly higher compared with the contralateral unsmoked lungs (4.3 +/- 0.15; P less than or equal to 0.05). The thermal-dye technique thus underestimates EVLW. Poor perfusion of the smoke-exposed lungs 24 h after injury was demonstrated indirectly by killing a group of sheep with T-61, an agent that causes a dark red coloration of well-perfused lung areas, as well as directly by measurement of blood flow utilizing a radiolabeled microsphere technique. Thus the inability of the thermal-dye technique to detect the lung edema may be the result of poor perfusion of the injured lung.


1994 ◽  
Vol 77 (3) ◽  
pp. 1116-1121 ◽  
Author(s):  
P. L. Khimenko ◽  
J. W. Barnard ◽  
T. M. Moore ◽  
P. S. Wilson ◽  
S. T. Ballard ◽  
...  

To determine the role of various Na+ transport systems in the edema fluid accumulation after ischemia and reperfusion in the lung, we evaluated the effect of amiloride (a Na+ channel blocker), ouabain (a Na(+)-K(+)-adenosinetriphosphatase blocker), and phloridzin (a Na(+)-glucose cotransport blocker) in isolated rat lungs. Ischemia and reperfusion (I/R) significantly increased the edema accumulation, with the wet-to-dry weight ratios increasing to 10.14 +/- 0.58 from 6.03 +/- 0.05 in control lungs (P < 0.04). Amiloride significantly augmented the amount of edema fluid (wet-to-dry weight ratio 12.26 +/- 0.77), and ouabain further increased the amount of edema (wet-to-dry weight ratio 18.58 +/- 1.00). Phloridzin did not significantly affect edema formation associated with I/R. Isoproterenol decreased the amount of edema formation in the presence and absence of amiloride. This occurred because the endothelial permeability as assessed by filtration coefficient was restored to normal values and less edema formed. The present study indicates that Na+ channels and Na(+)-K(+)-adenosinetriphosphatase, components of the active Na+ absorption transport system, are very important in opposing edema fluid accumulation in rat lungs subjected to I/R injury and operate as an edema safety factor. However, if the endothelial damage associated with I/R is allowed to persist, then the transport processes, even if operative, are insufficient to prevent continuous edema accumulation.


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