Obesity and Trauma

Reviewed and revised 26 October 2016


  • Obesity has significant implications for the assessment, management, and outcomes of trauma
  • The relationship between obesity and negative outcome from injury has been controversial


Obese patients tend to have lower overall injury severity scores and the pattern of injuries in blunt trauma differs from non-obese patients.

Injuries that are more likely:

  • pulmonary contusion, rib fractures and chest injuries
  • pelvic injuries
  • extremity injuries

Injuries that are less likely:

  • head injuries
  • liver and other significant abdominal injuries

Obese patients tend to have longer extraction times which may put them at greater risk of crush injury


Assessment is confounded by the Pathophysiology and Complications of Obesity

  • clinical examination less reliable, for example:
    • skin folds may mask penetrating injuries
    • difficult to auscultate and detect pneumothorax
    • difficult to assess for abdominal or bone tenderness
    • masses/ deformities difficult to palpate
    • use of inappropriate BP cuff size
    • difficulty performing log roll
  • FAST scan has the advantage of not requiring patient transfer but suffers from:
    • technical challenges (beam penetration and image quality)
    • decreased sensitivity, and
    • adipose tissue may resemble clotted blood (e.g. false positive pericardial collections)
  • Other imaging:
    • mediastinum appears wide on chest x-ray
    • size may preclude CT/ MRI imaging


  • difficult airway maintenance
    • e.g. obstruction lying flat, difficult intubation grade, difficult to perform BVM
  • impaired ventilation
    • e.g. obesity hypoventilation syndrome, poor chest wall compliance
  • disordered gas exchange
    • e.g. atelectasis, reduced FRC
  • aspiration risk
  • haemodynamic instability
  • nutritional requirements differ
    • increased caloric requirements in trauma, but hypocaloric high protein diet preferred in obese patients
    • may need indirect calorimetry
  • thromboprophylaxis
    • difficulties with anticoagulant dosing
    • may need IVC filter
  • chronic inflammatory state
  • altered pharmacokinetics
  • transport and positioning difficulties
    • e.g. delays, risk of staff injury
  • difficult procedures
    • e.g. IV/ IO access, intercostal catheter insertion, needle thoracostomy, difficult intubation, surgery, interventional radiology
  • need for special equipment
    • e.g. bariatric beds, hoists
  • monitoring problems
    • e.g. greater need for invasive BP monitoring
  • risk of discrimination and negative attitudes to obesity


Though the evidence is conflicting, obesity in trauma patients has been associated with:

  • increased mortality (x6 in blunt trauma)
  • increased LOS in ICU and hospital
  • increased rates of complications
  • increased time on mechanical ventilation
  • increased rates of organ dysfunction

References and Links


Journal articles

  • Bochicchio GV, Joshi M, Bochicchio K, Nehman S, Tracy JK, Scalea TM. Impact of obesity in the critically ill trauma patient: a prospective study. J Am Coll Surg. 2006;203:533–538. [PubMed]
  • Boulanger BR, Milzman D, Mitchell K, Rodriquez A. Body habitus as a predictor of injury pattern after blunt trauma. J Trauma. 1992;33:228–232. [PubMed]
  • Choban PS, Weireter LJ, Jr, Maynes C. Obesity and increased mortality in blunt trauma. J Trauma. 1991;31:1253–1257. [PubMed]
  • Diaz JJ, Jr, Norris PR, Collier BR, et al. Morbid obesity is not a risk factor for mortality in critically ill trauma patients. J Trauma. 2009;66:226–231. [PubMed]
  • Dossett LA, Heffernan D, Lightfoot M, et al. Obesity and pulmonary complications in critically injured adults. Chest. 2008;134:974–980. [PMC free article] [PubMed]
  • Newell MA, Bard MR, Goettler CE, et al. Body mass index and outcomes in critically injured blunt trauma patients: weighing the impact. J Am Coll Surg. 2007;204:1056–1061. [PubMed]
  • Liu T, Chen JJ, Bai XJ, Zheng GS, Gao W. The effect of obesity on outcomes in trauma patients: a meta-analysis. Injury. 2013 Sep;44(9):1145-52. doi: 10.1016/j.injury.2012.10.038. Epub 2012 Dec 4. PMID: 23219239.
  • Ryb GE, Dischinger PC. Injury severity and outcome of overweight and obese patients after vehicular trauma: a Crash Injury Research and Engineering Network (CIREN) study. J Trauma. 2008;64:406–411. [PubMed]
  • Sifri ZC, Kim H, Lavery R, Mohr A, Livingston DH. The impact of obesity on the outcome of emergency intubation in trauma patients. J Trauma. 2008;65:396–400. [PubMed]
  • Twaij A, Sodergren MH, Pucher PH, Batrick N, Purkayastha S. A growing problem: implications of obesity on the provision of trauma care. Obes Surg. 2013 Dec;23(12):2113-20. PMID: 24096925.
  • Viano DC, Parenteau CS, Edwards ML. Crash injury risks for obese occupants using a matched-pair analysis. Traffic Inj Prev. 2008;9:59–64. [PubMed]
  • Zarzaur BL, Marshall SW. Motor vehicle crashes obesity and seat belt use: a deadly combination?J Trauma. 2008;64:412–419. [PubMed]

CCC 700 6

Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.