Early physiologic predictors of injury severity and death in blunt multiple trauma
J. H. Siegel, A. I. Rivkind, S. Dalal and S. Goodarzi
Maryland Institute for Emergency Medical Services Systems, University of Maryland, Baltimore 21201.
The importance of admission physiological and biochemical variables was
modeled on data from 185 patients with blunt liver trauma with regard to
their significance in prediction of mortality. The variables used were
admission Glasgow Coma Score, base excess (or deficit), arterial lactate,
Injury Severity Score, and initial 24-hour volume of blood required for
replacement. Each variable was modeled as a predictor of survival alone and
in combination, using a linear logistic model. In any two-variable
combination, Glasgow Coma Score had a high likelihood ratio for prediction
representing the influence of brain injury. But as a single variable
reflecting the probability of death, both base excess (LD50 = -11.8 mmol/L)
and initial 24-hour volume of blood (LD50 = 5.4 L) were highly significant.
A combined logistic model of admission Glasgow Coma Score and base excess
had the greatest likelihood of accurate prediction of outcome: P death = e
lambda/l + e lambda; where lambda = -0.21(Glasgow Coma Score) -0.147(base
excess) + 0.285. Testing of this predictive model on data from 323
additional patients with multiple trauma who had pelvic fracture as their
index injury also showed it to be a highly significant early predictor of
outcome.
