ESTIMATION OF CONDENSED PULMONARY PARENCHYMA FROM GAS-EXCHANGE PARAMETERS IN PATIENTS WITH MULTIPLE TRAUMA AND BLUNT CHEST TRAUMA

Pulmonary gas exchange in correlation with condensed lung volume was p rospectively studied in 10 patients with multiple injuries and blunt c hest trauma, The purpose was to find nomograms that allow the estimati on of the extent of pulmonary density from gas exchange parameters, Th e condensed lung volume was determined planimetrically from serial tra nsverse sections of chest computed tomographic scans, There was no cor relation between condensed lung volume and mean pulmonary artery press ure, pulmonary vascular resistance, systemic vascular resistance, or c ardiac index and a week negative correlation to the oxygenation index (Pao(2)/Fio(2)) (r(2) = 0.46) and to the total static lung compliance (r(2) = 0.29), A strong correlation between pulmonary density and intr apulmonary shunt fraction (Qs/Qt) (r(2) = 0.95) as well as alveoloarte rial Po-2 difference (P(A-a)o(2)) (r(2) = 0.86) was evident, By using linear regression equations (linear regression line with 95% confidenc e interval), nomograms were calculated, The extent of pulmonary densit y can easily be obtained from these nomograms by measuring Qs/Qt or P( A-a)o(2). The presented nomograms may be helpful in monitoring the eff ect of treatment in patients with blunt chest trauma.