title: AIS>2 in at least two body regions: a potential new anatomical definition of polytrauma.
abstract: BACKGROUND
  The term 'polytrauma' lacks a universally accepted, validated definition. In clinical trials the commonly applied injury severity based anatomical score cut-offs are ISS > 15, ISS > 17 and a recently recommended AIS > 2 in at least two body regions (2 × AIS > 2).
  
  
  OBJECTIVE
  To compare the outcomes of clinically defined polytrauma patients with those defined based on anatomical scores.
  
  
  METHODS
  A prospective observational study on all trauma team activation patients over a 7-month period presenting at a level-1 trauma centre were included in the study. The prospective data collection included AIS in each body region, ISS, ICU length of stay (LOS), multiple organ failure (MOF) and mortality.
  
  
  RESULTS
  336 patients met inclusion criteria (age: 41 ± 20, 74% male, ISS: 15 ± 11, NISS: 19 ± 15, MOF: 3%, mortality: 4%, 25% ICU admission). ISS > 15: 13 deaths (10%), 71 (54%) required ICU admission and 10 (8%) developed MOF. ISS > 17 captured 11 deaths (11%), with 63 (62%) requiring ICU admission and 10 (10%) developing MOF. Defining as (2 × AIS > 2): 8 deaths (13% of the group), with 43 patients requiring ICU admission (67%) and 9 (14%) developing MOF. When examining the performance of these three approaches, the ISS > 15 and the ISS > 17 captured statistically the same amount of clinically defined polytrauma patients (p = 0.4106), while the 2 × AIS > 2 definition captured significantly more polytrauma patients than ISS > 15 (p = 0.0251) and ISS > 17 (p = 0.0019).
  
  
  CONCLUSIONS
  2 × AIS > 2 captured the greatest percentage of the worst outcomes and significantly larger % of the clinically defined polytrauma patients. 2 × AIS > 2 has higher accuracy and precision in defining polytrauma than ISS > 15 and ISS > 17. This simple, retrospectively also reproducible criteria warrants larger scale validation.
authors: Department of Traumatology, Division of Surgery, John Hunter Hospital and University of Newcastle, Newcastle, NSW, Australia.
authors: Nerida
authors: N
authors: Butcher
authors: Zsolt J
authors: ZJ
authors: Balogh
mesh_terms: D015998:Abbreviated Injury Scale; D000328:Adult; D000368:Aged; D005260:Female; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000175:diagnosis / Q000453:epidemiology*; D009104:Multiple Trauma / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D014194:Traumatology / Q000592:standards