Risk factors that are treatable:
(1) low hemoglobin (< 10 g/dL)
(2) elevated prothrombin time (> 14 seconds; reference range not given but value termed elevated so will use upper limit of reference range as cutoff)
(3) elevated activated partial thromboplastin time (> 34 seconds, mean 27.5, reference range not given but value termed elevated so will use upper limit of reference range as the cutoff)
(4) low systolic blood pressure at scene (< 100 mm Hg)
(5) low systolic blood pressure on admission to the ED (< 100 mm Hg)
(6) elevated base deficit (< -2 mmol/L; an elevated base deficit indicates a more negative value)
Risk factors that are untreatable:
(1) head injury (positive CT scan, GCS < 8))
(2) age (risk increases with age; will use >= 55)
(3) Injury Severity Score (ISS; range 0 to 75; risk if high; will use >= 16)
(4) revised trauma score (RTS; range 0 to 12, risk if low; will use < 7)
where:
• Age, ISS and RTS were continuous variables.
• To simplify the implementation I selected cut-off values that made sense to me. These values are therefore subject to change. I based the cutoffs for age and ISS on page 72 of Mattox et al, Trauma, 4th edition, 2000.
• Some factors may be in more than one score. For example, systolic blood pressure and the Glasgow coma score are included in the RTS.
Other risk factors:
(1) male gender
(2) penetrating trauma
