高濃度トリクロロエチレン曝露に伴った急性肺損傷の1例

A Case of Acute Lung Injury due to Exposure to High Concentration of Vapor Trichloroethylene

要旨

　患者は清掃業の24歳，男性．50%トリクロロエチレン溶液を用いた真空管熱処理の炉内清掃中に気分不良を訴えた後，意識消失．約60分間，炉の底で左側臥位にて高濃度トリクロロエチレン揮発環境下に曝露後，救出された．当センター搬入時，P/F比300未満と急性肺損傷を呈し，胸部X線写真にて左肺の透過性が低下していた．翌日のHRCTにて左肺に間質影が残存していたため気管支肺胞洗浄検査を行ったところ，性状は淡血性であるも，分画は正常であった．また，気管支粘膜生検では粘膜の浮腫を，経気管支肺生検ではリンパ球浸潤と肺胞間質の軽度線維性肥厚を認め，搬入翌日の尿中トリクロル酢酸は異常高値であった．これまでに高濃度トリクロロエチレンの長時間吸入による急性肺損傷報告例はなく，かつ片側肺のみに異常影を呈した貴重な症例と考え，報告する．

Summary

　The patient is a 24 year old man who cleaned the room in the factory. He became unconscious while he was cleaning the wall of the chamber where the vaccum tubes had been washed using 50% trichloroethylene solution. He was rescured about one hour after he had been exposed with high concentration of vapor trichloroethylene while he was lying unconscious on tne left decubitus position on the floor of the chamber.

　At the time of admission to our institution, his laboratory data strongly suggested acute pulmonary injury(P/F oxygen ratio was less than 300) and chest X-ray revealed decreased pulmonary permeability of the left side. A bronchoalveolaer lavage was done next morning since pulmonary high resolution CT scan had shown interstitial shadow on the left. The fluid of the lavage was slightly blood-tinged although its analysis was within normal ranges. Furthermore a transbronchial biopsy was performed on the same day and the mucosa appeared somewhat swollen. The histologic examination showed some lymphocyte infiltrates and fibrous thickening of the interalveoar septa. Urinalysis on one day after admission demonstrated high concentration of trichloroacetic acid. The patient recovered from pulmonary injury and was discharged from ICU on the 15th day.

　There have been no reports on acute pulmonary injury in the relation to long standing exposure of high concentration of trichloroethylene.

　We believe that our case is worth reporting because our case is very rare and it showed only left sided pulmonary injury.