[Diagnostic effect of bronchoalveolar lavage in early lung injury caused by enterogenic infection in rat].

OBJECTIVE: To study the diagnostic effect of bronchoalveolar lavage in early lung injury by observing changes in inflammatory mediators in early lung injury caused by enterogenic infection. METHODS: Eighty-four Sprague-Dawley rats were randomly divided into infection group and sham-operation group. Cecal ligation and perforation was utilized to produce abdominal infection in rats. Six groups were sacrificed respectively at 0, 24, 48, 72, 96, 120 hours after operation. The differential cell count in bronchoalveolar lavage fluid (BALF) was assessed. The concentrations of endotoxin, phospholipase A2 (PLA2) and tumor necrosis factor-alpha (TNF-alpha) in BALF, lung and plasma were assayed. RESULTS: The neutrophil percentage of BALF increased progressively. The concentrations of endotoxin, PLA2 and TNF-alpha in BALF, lung and plasma were significantly increased. The levels of endotoxin and PLA2 in lung tissue were respectively correlated positively with those in BALF and plasma (BALF and lung: r=0.904, P<0.05; BALF and plasma: r=0.895, P<0.05; lung and plasma: r=0.946, P<0.01). Significant positive correlation was also present between the TNF-alpha levels in BALF and lung (r=0.952 P<0.01), but not between the TNF-alpha level in plasma and that in lung or BALF (r=0.684, r=0.608, both P>0.05). CONCLUSION: The examinations of bronchoalveolar lavage may help discover early lung injury caused by enterogenic infection.