Pulmonary contusions: quantifying the lesions on chest X-ray films and the factors affecting prognosis.

OBJECTIVES: To quantify pulmonary contusions on chest x-ray film and to evaluate factors correlating with the size of the pulmonary contusions, changes in the first 24 hours, the need for ventilatory assistance, and death.
METHODS: The medical records and chest x-ray films of 103 patients with blunt chest trauma diagnosed as having a pulmonary contusion were reviewed.
RESULTS: A pulmonary contusion score was developed (3 = one third of a lung; 9 = an entire lung). In the emergency department, pulmonary contusions were not present in 11, were mild (one ninth to two ninths of a lung) in 15 patients, moderate-severe (three ninths to nine ninths of a lung) in 53 patients, and very severe in 24 patients. Within 24 hours, the pulmonary contusion score increased in 26 patients by 7.9 +/- 5.5 (SD). The 26 patients with an increasing contusion had a higher mortality rate (38% vs. 17%) (p = 0.044) and tended to need ventilatory assistance more frequently (73% vs. 49%) (p = 0.061). The 35 patients with very severe pulmonary contusions (pulmonary contusion score = 10-18) had the lowest PaO2:FIO2 ratio at 24 hours (175 +/- 103 mm Hg), longest hospital length of stay (28 +/- 35 days), and the highest Injury Severity Score (26 +/- 9). The factors correlating highest with a need for ventilatory support (57/103) were the 24 hour or initial PaO2/FIO2 ratio < 300, an Injury Severity Score > or = 24, Revised Trauma Score < 6.4, Glasgow Coma Scale score < or = 12, and shock or need for blood in the first 24 hours (p < 0.001). Death correlated highly with a need for ventilatory assistance, Injury Severity Score > or = 26, Revised Trauma Score < or = 6.3, and Glasgow Coma Scale score < or = 11 (p < 0.001).
CONCLUSION: Quantifying and noting changes in the extent of the pulmonary contusions and PaO2/FIO2 ratio during the first 24 hours may be of value in determining the need for ventilatory assistance and predicting outcome.