Changes in contused lung volume and oxygenation in patients with pulmonaryparenchymal injury after blunt chest trauma

Although it is well known that pulmonary parenchymal injury impairs oxygena tion, the relationship between hypoxemia and volume of the contused lung af ter blunt chest trauma remains unknown. We studied 23 blunt chest trauma pa tients who underwent thoracic computed tomography (CT) within 24 hours afte r admission and also underwent follow up CT at 1-week intervals until abnor mal lung findings disappeared, Contused lung volume was determined quantita tively by CT. CT findings of parenchymal injury were either a diffuse lesio n that disappeared within 1 week (n = 9 patients, group 1), or a solitary l esion that remained a few weeks after resolution of the diffuse lesion (n = 14 patients, group 2), PaO2/FiO(2) was positively correlated with the volu me of contused lung during the first 24 hours in both groups, however, ther e was no significant correlation after I week after injury. Degree of impai red oxygenation is related to the volume of the diffuse lesion that is reco gnized soon after injury.