Smoke inhalation injury: evaluation of radiographic manifestations and pulmonary dysfunction

Inhalation injury is a frequent complication in burned patients. Upper airway injury is reliably diagnosed endoscopically, but early diagnosis of pulmonary parenchymal injury is less reliable. Radiographic diagnosis in such cases is inconsistent. This study correlated degree of chest X-ray (CXR) change with pulmonary function in 29 adult patients during the first 5 days after inhalation injury. Daily CXRs were graded: 0 (normal), 1+ (peribronchial cuffing or perivascular edema), 2+ (edema involving one third of the lung field), 3+ (edema involving two thirds of the lung field), and 4+ (edema involving the entire lung field). Extravascular lung water volume (EVLW) was measured in vivo with the thermal/green dye double indicator technique. Twenty-five of the 29 patients were intubated on admission. Of these patients with serious inhalation injury, 84% showed some abnormality on CXR within 48 hours after injury. When abnormalities were present on CXR, pulmonary dysfunction (increases EVLW, increases Qs/Qt, decreases compliance) was clinically important. These data suggest that this grading scale may have utility in reports of CXR findings in inhalation injury.