title: Risk factors for post-traumatic pneumonia in patients with retained haemothorax: results of a prospective, observational AAST study.
abstract: BACKGROUND
  Retained haemothorax (RH) is a problematic sequela of thoracic trauma, reported in up to 20% of patients following chest injury. RH is associated with a higher severity of thoracic trauma and may portend the onset of other serious post-traumatic complications, including pneumonia. The development of pneumonia has previously been reported to be as high as 19.5% in the setting of traumatic RH. The purpose of this study was to identify risk factors for the development of pneumonia as a complication in RH.
  
  
  METHODS
  We utilized the American Association for the Surgery of Trauma Post-Traumatic Retained Haemothorax database. Patients with post-traumatic RH were prospectively enrolled from 2009 to 2011. Inclusion criteria were placement of a thoracostomy tube within 24h of admission for the evacuation of pneumothorax or haemothorax and subsequent chest computed tomography scan chest showing RH. Patients treated with thoracotomy before placement of tube thoracostomy were excluded. For univariate analysis, the Chi-square test with Yates correction was used for comparison of categorical risk factors and the Student's t-test or the Mann-Whitney test for comparison of continuous risk factors. To identify independent risk factors for the development of pneumonia, variables from the univariate analysis significant at p<0.2 were entered into a forward logistic regression model. Adjusted odds ratio and 95% confidence intervals (CI) were derived.
  
  
  RESULTS
  328 patients with post-traumatic RH from 20 United States centres were enrolled. After stepwise regression analysis, ISS>25 (adjusted OR: 7.1; 95% CI: 3.1, 16.4; p<0.001), blunt mechanism of injury (adjusted OR: 3.5; 95% CI: 1.7, 7.2; p=0.001), and failure to administer peri-procedural antibiotics on the initial thoracostomy tube placement (adjusted OR: 2.6; 95% CI: 1.30, 5.4; p=0.01) were found to be independent predictors of the pneumonia in patients with post-traumatic RH.
  
  
  CONCLUSIONS
  To our knowledge, our current study is the largest attempt to identify the independent predictors for pneumonia in this population. Our data show that elevated ISS, blunt thoracic trauma, and failure to administer peri-procedural antibiotics on tube thoracostomy placement are the statistically significant independent risk factors.
authors: Department of Trauma and Surgical Critical Care, University of Maryland Medical System/R Adams Cowley Shock Trauma, Baltimore, MD 21201, USA. mjbrad7@yahoo.com
authors: Matthew
authors: M
authors: Bradley
authors: Obi
authors: O
authors: Okoye
authors: Joseph
authors: J
authors: DuBose
authors: Kenji
authors: K
authors: Inaba
authors: Demetrios
authors: D
authors: Demetriades
authors: Thomas
authors: T
authors: Scalea
authors: James
authors: J
authors: O'Connor
authors: Jay
authors: J
authors: Menaker
authors: Carlos
authors: C
authors: Morales
authors: Tony
authors: T
authors: Shiflett
authors: Carlos
authors: C
authors: Brown
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D015505:Chest Tubes / Q000009:adverse effects*; D016009:Chi-Square Distribution; D005260:Female; D006491:Hemothorax / Q000150:complications* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000209:etiology* / Q000517:prevention & control*; D011446:Prospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric; D013898:Thoracic Injuries / Q000150:complications; D014949:Wounds, Nonpenetrating; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antibiotics; Pneumonia; Prospective observational study; Retained haemothorax; Risk factors; Trauma