title: Utility of admission physiology in the surgical triage of isolated ballistic battlefield torso trauma.
abstract: BACKGROUND
  An assessment of hemodynamic stability is central to surgical decision-making in the management of battlefield ballistic torso trauma (BBTT).
  
  
  OBJECTIVE
  To analyse the utility of admission physiological parameters in characterising hemodynamic stability.
  
  
  METHODS
  A retrospective analysis of consecutive admissions, with BBTT, to forward surgical facility in Afghanistan.
  
  
  METHODS
  The cohorts' admission physiology, need for operative intervention, and mortality data were collected retrospectively. The cohort was divided into patients requiring surgery for Life-Threatening Torso Hemorrhage (LTTH) and those not requiring immediate surgery (non-LTTH).
  
  
  METHODS
  Parameters were compared using two sample t tests, Mann-Whitney, Fisher's exact, and Chi-square tests. Receiver operator characteristic curves were used to identify significant parameters and determine optimum cut-off values.
  
  
  RESULTS
  A total of 103 patients with isolated BBTT were identified: 44 in the LTTH group and 59 in the non-LTTH group. The mean New Injury Severity Score ± Standard Deviation (NISS±SD) was 28±14 and 13±12, respectively. The heart rate, systolic blood pressure (SBP), pulse pressure, shock index (SI=heart rate/SBP) and base excess were analysed. SI correlated best with the need for surgical torso hemorrhage control, P<0.05. An optimal cut-off of 0.9 was identified, producing a positive and negative predictive value of 81% and 82%, respectively.
  
  
  CONCLUSIONS
  Shock index (SI) is a useful parameter for helping military surgeons triage BBTT, identifying patients requiring operative torso hemorrhage control. SI performance requires a normal physiological response to hypovolemia, and thus should always be considered in clinical context.
authors.affiliation: Academic Department of Military Surgery and Trauma, Royal Centre for Defence Medicine, Birmingham Research Park, Vincent Drive, Edgbaston, Birmingham B15 2SQ, UK.
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Morrison
authors.forename: Euan J
authors.initials: EJ
authors.lastname: Dickson
authors.forename: Jan O
authors.initials: JO
authors.lastname: Jansen
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Midwinter