title: Bedside thoracic ultrasonography of the fourth intercostal space reliably determines safe removal of tube thoracostomy after traumatic injury.
abstract: BACKGROUND
  Thoracic ultrasonography is more sensitive than chest radiography (CXR) in detecting pneumothorax; however, the role of ultrasonography to determine resolution of pneumothorax after thoracostomy tube placement for traumatic injury remains unclear. We hypothesized that ultrasonography can be used to determine pneumothorax resolution and facilitate efficient thoracostomy tube removal. We sought to compare the ability of thoracic ultrasonography at the second through fifth intercostal space (ICS) to detect pneumothorax with that of CXR and determine which ICS maximizes the positive and negative predictive value of thoracic ultrasonography for detecting clinically relevant pneumothorax resolution.
  
  
  METHODS
  A prospective, blinded clinical study of trauma patients requiring tube thoracostomy placement was performed at a university-based urban trauma center. A surgeon performed daily thoracic ultrasonographies consisting of midclavicular lung evaluation for pleural sliding in ICS 2 through 5. Ultrasonography findings were compared with findings on concurrently obtained portable CXR.
  
  
  RESULTS
  Of the patients, 33 underwent 119 ultrasonographies, 109 of which had concomitant portable CXR results for comparison. Ultrasonography of ICS 4 or 5 was better than ICS 2 and 3 at detecting a pneumothorax, with a positive predictive value of 100% and a negative predictive value of 92%. The positive and negative predictive values for ICS 2 were 46% and 93% and for ICS 3 were 63% and 92%, respectively.
  
  
  CONCLUSIONS
  Bedside, surgeon-performed, thoracic ultrasonography of ICS 4 for pneumothorax can safely and efficiently determine clinical resolution of traumatic pneumothorax and aid in the timely removal of thoracostomy tubes.
  
  
  METHODS
  Diagnostic study, level II.
authors.affiliation: Department of Surgery, University of California, San Francisco-East Bay, Oakland, California, USA.
authors.forename: Rita O
authors.initials: RO
authors.lastname: Kwan
authors.forename: Emily
authors.initials: E
authors.lastname: Miraflor
authors.forename: Louise
authors.initials: L
authors.lastname: Yeung
authors.forename: Aaron
authors.initials: A
authors.lastname: Strumwasser
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Victorino
mesh_terms: D000328:Adult; D000465:Algorithms; D015505:Chest Tubes; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D008297:Male; D011030:Pneumothorax / Q000000981:diagnostic imaging* / Q000209:etiology; D019095:Point-of-Care Systems; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013898:Thoracic Injuries / Q000150:complications / Q000000981:diagnostic imaging*; D013907:Thoracostomy / Q000379:methods; D013909:Thorax / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography