title: Body mass index affects the need for and the duration of mechanical ventilation after thoracic trauma.
abstract: BACKGROUND
  A higher body mass index (BMI) is associated with hypoxia, hypercarbia, and reduced functional residual capacity. The current study evaluates the association between BMI and the need for mechanical ventilation (MV) among patients who have sustained chest trauma.
  
  
  METHODS
  Demographic and clinical outcome data were collected from patients suffering blunt or penetrating thoracic traumatic injury admitted to a Level I academic trauma center between January 2001 and June 2006 (n = 3,649). Using logistic regression, the odds of being placed on MV were estimated according to BMI adjusting for the potentially confounding effects of age, mechanism of injury, severity of thoracic, head and overall injury, and pneumonia.
  
  
  RESULTS
  Compared with those with a normal BMI (18.5-24.9 kg/m), the odds of MV were not significantly different for underweight (BMI < 18.5 kg/m) patients (odds ratio [OR] 0.98, 95% confidence interval [CI] 0.53-1.80), but were elevated for overweight (BMI 25.0-29.9 kg/m) and obese (BMI 30+ kg/m) patients (OR 1.40, 95% CI 1.08-1.81 and OR 1.53, 95% CI 1.17-1.99, respectively).
  
  
  CONCLUSIONS
  Higher BMI values were positively associated with the initiation of MV. Among those patients on MV, an elevated BMI was significantly associated with a longer duration of MV. The field of acute trauma care would benefit from further evaluation of the association between BMI and MV so as to improve ventilation strategies for obese trauma patients.
authors.affiliation: Center for Injury Sciences at UAB, University of Alabama at Birmingham, Birmingham, Alabama 35294-0016, USA. dreiff@uab.edu
authors.forename: Donald A
authors.initials: DA
authors.lastname: Reiff
authors.forename: George
authors.initials: G
authors.lastname: Hipp
authors.forename: Gerald
authors.initials: G
authors.lastname: McGwin
authors.forename: Kayvon
authors.initials: K
authors.lastname: Modjarrad
authors.forename: Paul A
authors.initials: PA
authors.lastname: MacLennan
authors.forename: Loring W
authors.initials: LW
authors.lastname: Rue
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D012121:Respiration, Artificial; D013898:Thoracic Injuries / Q000628:therapy*; D013997:Time Factors