Effect of acid aspiration on right lymph duct lymph flow and prostaglandin metabolites in dogs
Aoyagi, M.
Masui. Japanese Journal of Anesthesiology 44(3): 331-337
1995
ISSN/ISBN: 0021-4892 PMID: 7745784 Document Number: 440197
Aspiration of acid gastric contents into the airways is a major cause of pulmonary injury. The author investigated the effects of intratracheal instillation of hydrochloric acid in the anesthetized dogs on pulmonary hemodynamics, pulmonary lymph flow and protein content, and stable metabolites of prostaglandin F-1-alpha (PGF-2-alpha), prostacyclin (PGI-2) and thromboxane A-2 (TXA-2). The author measured the concentrations of 15-keto-13,14-H-2-PGF-2-alpha, 6-keto-PGF-1-alpha and TXB-2 in blood and pulmonary (right duct) lymph by specific radioimmunoassay. After intratracheal instillation of 0.1 N HCL, 3 ml cntdot kg-1, the right duct lymph flow increased significantly from 1.3 to 4.5 ml cntdot h-1, and pulmonary lymph-to-plasma protein ratio increased significantly from 0.63 to 0.70. There was no significant change in hemodynamics after acid instillation. There was no significant change in arterial or mixed-venous blood levels of any of the three metabolites. After acid instillation, the right duct lymph concentrations increased 2-fold for PGI-2 metabolite, 3-fold for TXB-2, and 7-fold for PGF-2-alpha metabolite. The flow of metabolites (concentration X flow) increased 13-fold for 6-keto-PGF-1-alpha, 14-fold for TXB-2, and 40-fold for PGF-1-alpha metabolite. The author concludes that intratracheal instillation of hydrochloric acid in anesthetized dogs: 1) increases pulmonary microvascular permeability, and 2) stimulates the pulmonary generation of PGF-2-alpha, prostacyclin and thromboxane, and that 3) the analysis of pulmonary lymph flow and its constituents is a useful means for the study of lung injuries.