Marquez-Gonzalez et al developed a score to predict mortality for a critically-ill neonate. This is based on 9 variables and is referred to as the Neonatal Mortality Score-9 Mexico or EMN-9 Mex. The authors are from multiple neontatal units in Mexico.
Patient selection: critically-ill neonate
Outcome: mortality
Parameters:
(1) Apgar score at 5 minutes
(2) birthweight in grams
(3) blood gases
(4) blood lactate in mmol/L
(5) PaO2 to FIO2 ratio
(6) P(A-a)O2 in mm Hg
(7) a/A ratio (arterial to alveolar oxygen tension ratio, or PaO2/PAO2)
(8) platelet count per µL
(9) serum glucose in mg/dL
Parameter |
Finding |
Points |
---|---|---|
Apgar score at 5 minutes |
9 or 10 |
0 |
|
7 or 8 |
1 |
|
<= 6 |
2 |
birthweight in grams |
>=2,500 grams |
0 |
|
1,500 to 2,499 grams |
1 |
|
< 1,500 grams |
2 |
blood gases |
normal |
0 |
|
metabolic acidosis |
1 |
|
metabolic acidosis and anion gap >= 15 mmol/L |
2 |
blood lactate |
<= 1 mmol/L |
0 |
|
1.1 to 3.9 mmol/L |
1 |
|
>= 4.0 mmol/L |
2 |
PaO2 to FIO2 ratio |
>= 350 mm Hg |
0 |
|
200 to 349 mm Hg |
1 |
|
< 200 mm Hg |
2 |
P(A-a)O2 |
<= 100 mm Hg |
0 |
|
101 to 299 mm Hg |
1 |
|
>= 300 mm Hg |
2 |
a/A ratio |
>= 0.6 |
0 |
|
0.26 to 0.59 |
1 |
|
<= 0.25 |
2 |
platelet count |
>= 150,000 per µL |
0 |
|
50,001 to 149,999 per µL |
1 |
|
<= 50,000 per µL |
2 |
serum glucose |
<= 126 mg/dL |
0 |
|
127 to 200 mg/dL |
1 |
|
> 200 mg/dL |
2 |
where:
• The paper uses the A/a ratio but the a/A ratio is used in textbooks.
total score =
= SUM(points for all 9 parameters)
Interpretation:
• minimum score: 0
• maximum score: 18
• The greater the score the greater the risk for mortality.
Score |
Positive Likelihood Ratio |
---|---|
<= 7 |
0.08 |
8 to 11 |
0.21 |
12 to 15 |
1.9 |
16 to 19 |
10 |
Performance:
• The area under the ROC curve for a cutoff >= 16 was 0.95.
Specialty: Critical Care, Emergency Medicine, Pedatrics