Prevalence and importance of pneumothoraces visualized on abdominal computed tomographic scan in children with blunt trauma.

BACKGROUND: Chest radiographs are routinely obtained for the identification of pneumothoraces in trauma patients. Computed tomographic (CT) scanning has a higher sensitivity for the detection of pneumothoraces, but the prevalence and importance of pneumothoraces detectable by CT scan but not by chest radiography in children sustaining blunt trauma is unclear.
METHODS: We conducted a prospective observational cohort study of children less than 16 years old with blunt trauma undergoing both abdominal CT scan and chest radiography in the emergency department of a Level I trauma center over a 28-month period. All abdominal CT scans were interpreted by a single faculty radiologist. The chest radiographs of all patients with pneumothoraces detected on CT scan as well as a random sample of chest radiographs from pediatric blunt trauma patients without pneumothoraces on abdominal CT scan (in a ratio of four normals per pneumothorax) were reviewed by a second faculty radiologist. Both radiologists were masked to all clinical data as well as to the objective of the study.
RESULTS: Five hundred thirty-eight children underwent both abdominal CT scan and chest radiography in the emergency department. Twenty patients (3.7%; 95% confidence interval [CI], 2.3-5.7%) were found to have pneumothoraces on CT scan. Of these 20 patients, 9 (45%; 95% CI, 23-68%) had pneumothoraces identified on initial chest radiography and 11 patients did not ("unsuspected pneumothoraces"). Twelve pneumothoraces were identified in these 11 patients; 6 were graded as minuscule and 6 as anterior according to a previously established scale. One patient with an unsuspected pneumothorax underwent tube thoracostomy. None of the 10 patients (0%; 95% CI, 0-26%) with unsuspected pneumothoraces who were managed without thoracostomy (including two patients who underwent positive pressure ventilation) had complications from their pneumothoraces.
CONCLUSION: Less than half of pediatric blunt trauma patients with pneumothoraces visualized on abdominal CT scan had these pneumothoraces identified on initial chest radiograph. Patients with pneumothoraces identified solely on abdominal CT scan, however, uncommonly require tube thoracostomy.