title: Average chest wall thickness at two anatomic locations in trauma patients.
abstract: BACKGROUND
  Needle thoracostomy is the emergent treatment for tension pneumothorax. This procedure is commonly done using a 4.5cm catheter, and the optimal site for chest wall puncture is controversial. We hypothesize that needle thoracostomy cannot be performed using this catheter length irrespective of the site chosen in either gender.
  
  
  METHODS
  A retrospective review of all chest computed tomography (CT) scans obtained on trauma patients from January 1, 2011 to December 31, 2011 was performed. Patients aged 18 and 80 years were included and patients whose chest wall thickness exceeded the boundary of the images acquired were excluded. Chest wall thickness was measured at the 2nd intercostal (ICS), midclavicular line (MCL) and the 5th ICS, anterior axillary line (AAL). Injury severity score (ISS), chest wall thickness, and body mass index (BMI) were analyzed.
  
  
  RESULTS
  201 patients were included, 54% male. Average (SD) BMI was 26 (7)kg/m(2). The average chest wall thickness in the overall cohort was 4.08 (1.4)cm at the 2nd ICS/MCL and 4.55 (1.7)cm at the 5th ICS/AAL. 29% of the overall cohort (27 male and 32 female) had a chest wall thickness greater than 4.5cm at the 2nd ICS/MCL and 45% (54 male and 36 female) had a chest wall thickness greater than 4.5cm at the 5th ICS/AAL. There was no significant interaction between gender and chest wall thickness at either site. BMI was positively associated with chest wall thickness at both the 2nd and 5th ICS/AAL.
  
  
  CONCLUSIONS
  A 4.5cm catheter is inadequate for needle thoracostomy in most patients regardless of puncture site or gender.
authors.affiliation: Section of Trauma and Acute Care Surgery, Department of Surgery, George Washington University, United States.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Schroeder
authors.forename: Carrie
authors.initials: C
authors.lastname: Valdez
authors.forename: Andres
authors.initials: A
authors.lastname: Krauthamer
authors.forename: Nadia
authors.initials: N
authors.lastname: Khati
authors.forename: Jessica
authors.initials: J
authors.lastname: Rasmus
authors.forename: Richard
authors.initials: R
authors.lastname: Amdur
authors.forename: Kathleen
authors.initials: K
authors.lastname: Brindle
authors.forename: Babak
authors.initials: B
authors.lastname: Sarani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011030:Pneumothorax / Q000000981:diagnostic imaging / Q000601:surgery*; D012189:Retrospective Studies; D013898:Thoracic Injuries / Q000601:surgery*; D035441:Thoracic Wall / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery; D013907:Thoracostomy / Q000379:methods*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Needle thoracostomy; Tension pneumothorax