Influence of detergent aerosol on lung microvascular permeability

Abstract

Noncardiogenic edema fluid often contains high levels of plasma proteins, which may inhibit the function of the lung surfactant complex and thus decrease interstitial hydrostatic pressures. We questioned whether, in the awake and standing animal, displacement of the alveolar surface lining would alter the permeability of the thin and sparsely supported pulmonary capillaries. Sheep prepared with lung lymph fistulae were given an aerosolized detergent (Det) to displace the lung surfactant complex. After the sheep were given Det, protein flux was significantly increased (P < 0.05). To validate the suggested permeability increase, pulmonary vein occluders were surgically implanted and experiments repeated with pulmonary arterial pressures elevated 10 mmHg above baseline. After 2 h of elevated pulmonary arterial pressure, lung lymph increased fivefold. At this time, lymph-to-plasma total protein concentration ratios for air and saline-plus-ethanol vehicle were significantly lower (P < 0.01) than baseline ratios (0.26 +/- 0.06 and 0.34 +/- 0.07, respectively). No significant difference could be shown in lymph-to-plasma ratios after the sheep were given Det. We conclude that disruption of the alveolar lining can cause a detectable increase in protein flux due, in part, to an increase in microvascular permeability.

Ventilator-induced Lung Injury

“…The effects of surfactant inactivation on the microvascular endothelial barrier properties have not been unambiguously characterized. Experiments were conducted in dogs (145) and sheep (146) given aerosolized detergent. Microvascular permeability was assessed by analysis of lymph-to-plasma protein ratio during hydrostatic edema caused by increased pulmonary venous pressure.…”

“…Microvascular permeability was assessed by analysis of lymph-to-plasma protein ratio during hydrostatic edema caused by increased pulmonary venous pressure. Bredenberg and colleagues found that this ratio fell, indicating an unchanged protein reflection coefficient (145), whereas Wang and coworkers reported that this ratio was unchanged, indicating increased microvascular permeability to proteins (146). The reasons for these discrepancies were unclear.…”

Rapid Tracheal Infusion of Surfactant versus Bolus Instillation in Rabbits: Effects on Oxygenation, Blood Pressure and Surfactant Distribution

“…Since the initial report of surfactant substi tution for effective treatment of respiratory distress syndrome [1], various clinical trials have proven its value in decreasing mortality rates as well as reducing the incidence of com plications such as pneumothorax [2][3][4], The optimal mode of surfactant administration is K A R Ci F R © 1996 S. Karger AG, Basel l \ / 'V I \ V J c l \ 0006-3126/96/0692-0119S10.00/0 E-Mail karger(a>kargcr.ch F a x + 41 61 306 12 34 still under debate. The standard method of tracheal bolus instillation was derived from animal studies showing that the direct instilla tion of surfactant into the trachea improves oxygenation better and longer than delivery as an aerosol [5,6], However, undesirable side effects of bolus instillation have been re-ported, such as a transient decrease in blood pressure [7][8][9][10], changing cerebral blood flow velocity and cerebral blood volume [8, 9,11,12], as well as arterial carbon dioxide tension (PaCOy) changes [5,10].…”

Sustained improvement of gas exchange and lung mechanics by vaporized perfluorocarbon inhalation in piglet acute lung injury model

“…A 2% detergent solution containing dioctyl sulfosuccinate sodium salt (PN 323586, purity 98%, Sigma, USA), ethanol and saline was used to induce lung injury as described previously . The detergent solution (1–2 mL/kg) was instilled into the lung of the anesthetized animals until it was stable on the ventilator.…”