title: The immediate effect of burn wound excision on pulmonary function in sheep: the role of prostanoids, oxygen radicals, and chemoattractants.
abstract: Pulmonary dysfunction is a well-recognized complication of burn wound excision. It remains unclear whether this is caused by bacteria or inflammatory mediators released during excision of the wound. We produced a 15% full-thickness burn in 18 sheep, and between days 5 and 7 completely excised the wound under general anesthesia. Pulmonary parameters of static and dynamic lung compliance (CSTAT and CDYN), PaO2/FiO2, and pulmonary artery pressure (Ppa) were measured, as well as burn lymph, venous and aortic thromboxane B2 (TxB2), chemotactic index (chemotaxis/chemikinesis), and oxygen radical activity reflected in the level of lipid peroxidation in lung tissue. We noted a transient increase in burn lymph and venous TxB2 during excision, increasing from a preburn value of 200 and 220 +/- 50 pg/ml to 950 +/- 210 and 980 +/- 280 pg/ml, respectively. In 13 of 18 sheep, chemotactic activity and lung tissue lipid peroxidation, measured as malondialdehyde (MDA) content, were not increased. In this group only a very transient decrease in CDYN, PaO2/FiO2, and a 3 mm Hg increase in mean Ppa was seen with excision, with these parameters returning rapidly to baseline. Five of the 13 sheep had wound biopsy specimens that were greater than 10(6) organisms/gm tissue. In the remaining five sheep, plasma chemotactic index was also significantly increased with excision, as was lung MDA content, while decreases in CDYN, CSTAT, and PaO2/FiO2 and an increase in Ppa were more protracted. Three of these five sheep had wound biopsy specimens greater than 10(6) organisms/gm. We conclude that a release of thromboxane occurs during excision, which corresponds in time to transient lung dysfunction. If there is also a release of chemotactic factors, a more protracted pulmonary response occurs with evidence of O2 radical-induced lung changes.
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000378:metabolism; D000758:Anesthesia; D000818:Animals; D002056:Burns / Q000601:surgery*; D002630:Chemotactic Factors / Q000097:blood / Q000502:physiology*; D004195:Disease Models, Animal; D008168:Lung / Q000378:metabolism / Q000503:physiopathology*; D008170:Lung Compliance; D008196:Lymph / Q000032:analysis; D008315:Malondialdehyde / Q000096:biosynthesis; D010100:Oxygen / Q000378:metabolism*; D011453:Prostaglandins / Q000502:physiology*; D011669:Pulmonary Wedge Pressure; D012756:Sheep; D013929:Thromboxane B2 / Q000378:metabolism; D014655:Vascular Resistance
chemical_list: D002630:Chemotactic Factors; D011453:Prostaglandins; D008315:Malondialdehyde; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D010100:Oxygen