title: Rapid detection of pneumothorax by ultrasonography in patients with multiple trauma.
abstract: BACKGROUND
  Early detection of pneumothorax in multiple trauma patients is critically important. It can be argued that the efficacy of ultrasonography (US) for detection of pneumothorax is enhanced if it is performed and interpreted directly by the clinician in charge of the patients. The aim of this study was to assess the ability of emergency department clinicians to perform bedside US to detect and assess the size of the pneumothorax in patients with multiple trauma.
  
  
  METHODS
  Over a 14 month period, patients with multiple trauma treated in the emergency department were enrolled in this prospective study. Bedside US was performed by emergency department clinicians in charge of the patients. Portable supine chest radiography (CXR) and computed tomography (CT) were obtained within an interval of three hours. Using CT and chest drain as the gold standard, the diagnostic efficacy of US and CXR for the detection of pneumothorax, defined as rapidity and accuracy (sensitivity, specificity, positive predictive value, negative predictive value), were compared. The size of the pneumothorax (small, medium and large) determined by US was also compared to that determined by CT.
  
  
  RESULTS
  Of 135 patients (injury severity score = 29.1 +/- 12.4) included in the study, 83 received mechanical ventilation. The time needed for diagnosis of pneumothorax was significantly shorter with US compared to CXR (2.3 +/- 2.9 versus 19.9 +/- 10.3 minutes, p < 0.001). CT and chest drain confirmed 29 cases of pneumothorax (21.5%). The diagnostic sensitivity, specificity, positive and negative predictive values and accuracy for US and radiography were 86.2% versus 27.6% (p < 0.001), 97.2% versus 100% (not significant), 89.3% versus 100% (not significant), 96.3% versus 83.5% (p = 0.002), and 94.8% versus 84.4% (p = 0.005), respectively. US was highly consistent with CT in determining the size of pneumothorax (Kappa = 0.669, p < 0.001).
  
  
  CONCLUSIONS
  Bedside clinician-performed US provides a reliable tool and has the advantages of being simple and rapid and having higher sensitivity and accuracy compared to chest radiography for the detection of pneumothorax in patients with multiple trauma.
authors.affiliation: Department of Emergency Medicine, Second Affiliated Hospital, Zhejiang University, School of Medicine and Research Institute of Emergency Medicine, Hangzhou, China. zmhz@hotmail.com
authors.forename: Mao
authors.initials: M
authors.lastname: Zhang
authors.forename: Zhi-Hai
authors.initials: ZH
authors.lastname: Liu
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Yang
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Gan
authors.forename: Shao-Wen
authors.initials: SW
authors.lastname: Xu
authors.forename: Xiang-Dong
authors.initials: XD
authors.lastname: You
authors.forename: Guan-Yu
authors.initials: GY
authors.lastname: Jiang
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000150:complications / Q000000981:diagnostic imaging*; D011030:Pneumothorax / Q000150:complications / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors; D014463:Ultrasonography