[Experimental study of pulmonary infection and its systemic dissemination in the early stage of severe burn]

A total of 138 rabbits were used for the study of pulmonic infection and systemic dissemination in early stage of severe burns. One group of animals was inflicted with third degree burns on the back covering 20% of total body surface area; coincidently an intratracheal introduction of sero-type IX pseudomonas aeruginosa (IXPA) were performed. Above group of animals were compared with the simple body surface burns, simple intratracheal colonization and amikacin treatment groups. For observation, a series of blood samples, swabs of throat were taken at regular times for bacterial culture and IXPA identification. Endotoxin levels of blood plasma were measured too. Animals were killed at 8, 16, 24, 72 hours post-injury, tissue specimens of lung, liver, spleen and kidney were taken for quantitative bacterial cultures, and lung tissues for histological examination. The results showed that the predominant colonization of IXPA in the throats in burned animals are more difficult to be eliminated than that of in non-burned ones. The susceptibility of drugs to IXPA in burned group is higher than that of in control groups, with more severe tissue damages under microscopic examination. The pathogen of pulmonary infection began to invade into the blood stream at four hours post-injuries, and multiple organs dissemination occurred, in which the livers and kidneys were primarily affected. Coincidently a process of endotoxemia was proved. The systemic use of sensitive antibiotics immediately after burns showed benefit to decrease the rate of bacteremia and dissemination of other organs, as well as the rate of death.