TEMPORAL PATTERNS OF RADIOGRAPHIC INFILTRATION IN SEVERELY TRAUMATIZED PATIENTS WITH AND WITHOUT ADULT-RESPIRATORY-DISTRESS-SYNDROME

We prospectively evaluated the patterns of pulmonary structural and fu nctional changes in 100 consecutive surgical intensive care unit traum a patients who had (1) emergent major surgery, (2) a pelvic fracture, or (3) two or more major long bone fractures. For each patient, arteri al blood gas measurements (ABGs), central venous pressure (CVP), pulmo nary capillary occlusion pressure (PAOP), thoracic compliance, arteria l oxygen tension/fraction of inspired oxygen (PAo2/FIO2), pulmonary ve nous admixture (Qs/Qt), and portable chest roentgenograms were sequent ially tracked. The senior staff radiologist interpreted all chest roen tgenograms. Pulmonary infiltration was quantitated in each of six fiel ds using a scale ranging from 0 to 4, with 0 being no infiltration and 4 being the maximum. Adult respiratory distress syndrome (ARDS) was d efined as follows: Qs/Qt greater-than-or-equal-to 20%, PAo2/FIO2 < 250 or both; dependence on mechanical ventilation for life support for gr eater-than-or-equal-to 24 hours; PAOP or CVP or both <20 mm Hg; and th oracic compliance <50 mL/cm H2O. Time zero (T0) the time of onset of A RDS, was defined as the time these criteria were met. Eighty-three of 100 study group patients had penetrating injuries, and 17 were admitte d with blunt trauma. Fifty-one of 100 patients developed ARDS: 36 of 5 1 died. Only 4 of 49 (8%) patients without ARDS died. The injured lung s of patients with and without ARDS had similar amounts of infiltratio n over most measured time intervals. The noninjured lungs of the ARDS patients, however, had significantly greater infiltration than those w ithout ARDS at T0 and over subsequent time intervals. Before T0, the t otal infiltration of the injured lungs was significantly greater than that for the noninjured lungs in both the ARDS and nonARDS patient gro ups (4.5 +/- 0.6 vs. 0.7 +/- 0.2 and 2.4 +/- 0.4 vs. 0.4 +/- 0.3, resp ectively). The infiltration in the injured and noninjured lungs in bot h groups converged at T0 and remained similar for several days. We con clude that pulmonary infiltration develops simultaneously with lung dy sfunction in trauma patients with evolving ARDS. Densities associated with ARDS are first visible in the upper and middle lung fields.