Alveolar albumin leakage during large tidal volume ventilation and surfactant dysfunction

Detergent given as an aerosol and large tidal volume ventilation (LTVV) have been observed, by us, to promote lung injury by an additive effect on alveolocapillary barrier function. The surfactant system may be further damaged if protein leakage occurs into the alveoli. The aim was to study the effect of detergent and LTVV on the alveolar leakage of albumin and also the effect of detergent on surface activity of lung washings and lung tissue extracts. Technetium-99m-labelled human serum albumin was given intravenously. The alveolar leakage of albumin was measured after perturbing the surfactant system with the detergent dioctyl sodium sulfosuccinate either singly or in combination with LTVV. Four groups of rabbits were studied after 3 h of experimental ventilation. Surface tension measurements of tissue extracts, lung mechanics and gas exchange did not show any differences between groups. Wet lung weight and albumin leakage were significantly increased in the two groups subjected to LTVV compared with groups given normal tidal volume ventilation. Low doses of detergent did not affect surface activity of lung tissue extracts or alveolar leakage of albumin. LTVV increased alveolar leakage of albumin and produced oedema. No additive effect was seen when detergent and LTVV were combined.