Systemic thermal injury in anesthetized rabbits causes early pulmonary vascular injury that is not ablated by lazaroids

Purpose: To study the effects of a systemic thermal injury on the pulmonary vasculature with and without inhibitors of lipid peroxidation (U74389G). Methods: In a prospective, placebo control. randomized, and blinded multi-g roup study. burn shock was induced by scalding thermal injury (65C) to 35% body surface area in rabbits (n = 28). Hemodynamics and gas exchange were f ollowed for 240 min post burn in four groups; No Burn, Bum-Control, Burn-U7 4 (10 mg.Kg(-1) U74389G), No Burn-U74 (10 mg.Kg(-1) U74389G). Results: Scald resulted in early pulmonary injury-as measured by increased pulmonary vascular resistance in the pooled Burn group compared with the No Burn groups (942 +/- 358 vs 605 +/- 255 dynes.sec(-1).cm(-5) respectively, P < 0.05), These pulmonary changes were associated with alveolar sequestra tion or leukocytes (4.8 +/- 2.9 vs 17.7 +/- 6.0 cells x 10(9).L-1, P < 0.05 ) in the No Burn and Burn groups respectively, Histological evidence of dec reased neutrophil sequestration after scald injury was present in U74 treat ed animals (3(+) vs 2(+), P < 0.05 in the Burn and No Burn groups respectiv ely and 2(+) vs 2(+), P > 0.05 in the Burn-U74 and No Burn-U74 groups respe ctively) although bronchial alveolar lavage still demonstrated neutrophil s equestration (5.3 +/- 2.5 vs 12.2 +/- 3.3 cell 10(9)L(-1), P < 0.05 in No B urn-U74 and Burn-U74 groups respectively). Similarly circulating while bloo d cells were increased in the Burn group but not Burn-U74 group tour hours post burn, The increase in pulmonary vascular resistance after burn was not altered by administration of U74, Conclusions: Systemic burn results in early pulmonary vascular changes asso ciated with leukocyte sequestration, After raid injury administration of la zaroids (U744389G) did not lessen pulmonary vascular resistance changes but did reduce neutrophil sequestration.