Early Physiologic Predictors of Mortality After Blunt Multiple Trauma

 

Parameters used to derive logistic regression equations, alone and in pairs:

(1) Glasgow Coma Score

(2) Injury Severity Score

(3) blood replacement during first 24 hours in liters (approximately 4 units packed RBCs per liter)

(4) blood lactate

(5) base excess: The base excess of the extracellular fluid is felt to be a better estimate of the effective total body base deficit than the base excess in the blood.

 

base excess extracellular fluid (ECF) in mmol/L =

= (0.993 * (base excess for blood in mmol/L) + 0.184

 

The best predictor of mortality was use of both the Glasgow Coma Score and base excess.

 

X =

= (-0.21 * (Glasgow coma score)) - (0.147 * (base excess)) + 0.285

 

percent mortality =

= EXP(X) / (1 + EXP(X)) =

= 1 / (1 + EXP((-1)* X))

Variables	Equation for X	LD-50
blood replacement in first 24 hours (Figure 4)	= (0.35 * (blood volume in liters)) - 1.9	5.4 liters in 24 hours
Glasgow Coma Score (Figure 5)	= (-0.255 * (GCS)) + 1.88	GCS 7
Injury Severity Score (Figure 6)	= (0.063 * (ISS)) - 3.35	ISS 53
lactate on admission (Figure 7)	= (0.279 * (lactate in mmol/L)) - 2.65	9.5 mmol/L
base excess on admission (Figure 8)	= (-0.188 * (base excess ECF in mmol/L)) - 2.229	-11.8 mmol/L
GCS and blood replacement (Figure 9)	= (-0.254 * (GCS)) + (0.3 * (blood volume in liters)) + 1.1

 

Limitations:

• The commentary by Dr Trunkey on page 508 pointed that pulmonary and cardiac function were often early determinants of mortality. These were not included in the current studies but might be added in later versions.