Murdock et al developed a linear discriminant score for predicting survival in a neonate who develops the respiratory distress syndrome (RDS). The authors are from the University of Toronto and the Hospital for Sick Children in Toronto.
Parameters:
(1) birth weight in grams
(2) gestational age in weeks
(3) body temperature in °C (rectal)
(4) respiratory rate in breaths per minute
(5) PaO2 in mm Hg
(6) hydrogen ion concentration in nEq/L
(7) PaCO2 in mm Hg
discriminant score =
= (0.041 * (body weight in grams)) + (1.8 * (gestational age)) + (0.87 * (body temperature)) + (0.38 * (respiratory rate)) + (0.90 * (PaO2)) - (2.74 * (hydrogen ion concentration)) + (0.75 * (PaCO2))
where"
• pH = -LOG10(hydrogen ion concentration); hydrogen ion concentration in nEq/L = nmol/L = 10^(9 - (pH))
The probability of survival is read off the graph in Figure 2.
Discriminant Score
Probability of Survival
< - 150
< 3%
-150 to - 50
(0.000563 * ((score)^2)) + (0.2064 * (score)) + 20.93
-50 to 150
(0.000286 * ((score)^2)) + (0.2034 * (score)) + 21.29
150 to 400
(-0.000546 * ((score)^2)) + (0.4591 * (score)) + 1.304
> 400
> 97.5%
Limitations:
• The score was reported in 1971. Survival has improved since then so the reported survival is probably an underestimate.
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Specialty: Pulmonology, Pedatrics
