Occult Pneumothoraces in Children With Blunt Torso Trauma

Abstract

Objectives: Plain chest x-ray (CXR) is often the initial screening test to identify pneumothoraces in trauma patients. Computed tomography (CT) scans can identify pneumothoraces not seen on CXR ("occult pneumothoraces"), but the clinical importance of these radiographically occult pneumothoraces in children is not well understood. The objectives of this study were to determine the proportion of occult pneumothoraces in injured children and the rate of treatment with tube thoracostomy among these children.Methods: This was a planned substudy from a large prospective multicenter observational cohort study of children younger than 18 years old evaluated in emergency departments (EDs) in the Pediatric Emergency Care Applied Research Network (PECARN) for blunt torso trauma from May 2007 to January 2010. Children with CXRs as part of their trauma evaluations were included for analysis. The faculty radiologist interpretations of the CXRs and any subsequent imaging studies, including CT scans, were reviewed for the absence or presence of pneumothoraces. An "occult pneumothorax" was defined as a pneumothorax that was not identified on CXR, but was subsequently demonstrated on cervical, chest, or abdominal CT scan. Rates of pneumothoraces and placement of tube thoracostomies and rate differences with 95% confidence intervals (CIs) were calculated.Results: Of 12,044 enrolled in the parent study, 8,020 (67%) children (median age = 11.3 years, interquartile range [IQR] = 5.3 to 15.2 years) underwent CXRs in the ED, and these children make up the study population. Among these children, 4,276 had abdominal CT scans performed within 24 hours. A total of 372 of 8,020 children (4.6%; 95% CI = 4.2% to 5.1%) had pneumothoraces identified by CXR and/ or CT. The CXRs visualized pneumothoraces in 148 patients (1.8%; 95% CI = 1.6% to 2.2%), including one false-positive pneumothorax, which was identified on CXR, but was not demonstrated on CT. Occult pneumothoraces were present in 224 of 372 (60.2%; 95% CI = 55.0% to 65.2%) children with pneumothoraces. Tube thoracostomies were performed in 85 of 148 (57.4%; 95% CI = 49.0% to 65.5%)

Occult pneumothoraces in ventilated pediatric trauma patients: a review

“…1,2 In adults, pneumothoraces can occur in up to 64% of the most severely injured, ventilated patients. 3 Currently there is no clinical consensus on how to treat occult versus overt pneumothoraces in adults, and even less research has been done in children.…”

“…A more recent study with a larger population of ventilated children showed a progression rate up to 38%. 2 Our objective was to understand how our institution has managed occult pneumothoraces in severely injured children on mechanical ventilation.…”

“…9 The largest prospective trial on occult pneumothoraces in children after blunt trauma was recently conducted by Lee and colleagues. 2 Out of 224 children with occult pneumothoraces (4.7% incidence rate), only 35 (16%) needed chest tubes. However, all of the children who required tube thoracostomy were either intubated in the PICU (17 of 45) or intubated for an operation (19 of 80).…”

“…However, all of the children who required tube thoracostomy were either intubated in the PICU (17 of 45) or intubated for an operation (19 of 80). 2 Owing to the large number of centres involved in the study, there was considerable variety in the percentage of intubated patients who received tube thoracostomies (6%-49%). The authors acknowledge that this variability indicates that management of tube thoracostomies should be standardized across institutions.…”

Occult Pneumothorax Identification on Extended Focused Assessment with Sonography for Trauma Examination in Children

“…One large study of more than 8000 pediatric trauma patients reported that tube thoracostomy was performed in 57.4% of patients with nonoccult pneumothorax (PTX) and 15.6% of patients with OPTXs, with an interfacility range of 0% to 49% for all PTXs. 2 However, studies on the need for intervention in patients with OPTXs are difficult to interpret, as tube thoracostomy might be performed prophylactically, without clear patient decompensation. When end points of patient decompensation or PTX expansion are studied, smaller studies demonstrate these outcomes in approximately 6% of all patients, 3 with even lower frequency for children.…”