Healthcare & Clinical Calculators
SNAPPE-II (Score for Neonatal Acute Physiology with Perinatal Extension-II)
Sum first-12-hour NICU physiologic and perinatal SNAPPE-II subscores (0–162) and compute Douglas Richardson et al.’s (2001) neonatal hospital mortality probability.
Benchmarking NICU acuity across ALL birthweights with 6 physiologic + 3 perinatal risk factors!
Whereas CRIB-II applies strictly to <= 32-week very-low-birthweight preterms, Douglas K. Richardson et al. (Journal of Pediatrics, 2001; n = 25,429 newborns across 30 NICUs) validated SNAPPE-II across ALL birthweight and gestational-age cohorts! SNAPPE-II sums 9 objective variables from the first 12 hours of NICU admission (0–162 points): Mean Blood Pressure (0/9/19), Lowest Temperature (0/8/15), PO2/FiO2 Ratio (0/5/16/28), Lowest Serum pH (0/7/16), Multiple Seizures (0/19), Urine Output (0/5/18), plus Perinatal Extension Birthweight (0/10/17), 5-Min Apgar < 7 (0/18), and Small for Gestational Age < 3rd percentile (0/12)!
Evaluate a critically ill newborn summing 50 SNAPPE-II points (Respiratory/Acidosis = 14, Hypotension = 9, Birthweight 750–999g = 10, Low Urine Output = 5, SGA < 3rd pct = 12): overall all-birthweight logistic risk P(%) = 100 / (1 + EXP(-(-5.188 + 0.0632 * S))) yields 11.63% NICU mortality—dropping to 0.76% for a mild 5-point admission!
| 12-Hour NICU SNAPPE-II Total (0–162) | All-Birthweight Logit (-5.188 + 0.0632*S) | Predicted NICU Mortality (%) | NICU Acuity Tier |
|---|---|---|---|
| 5 Points (Mild Transitional Distress) | -4.872 | 0.76% | Low Acuity (< 20) |
| 50 Points (Multi-System Perinatal Stress) | -2.028 | 11.63% | High Acuity (>= 40 High Risk) |
| Negative Subscore (< 0) | Undefined | "Subscores Cannot Be Negative" | Input Validation Guard |
Total SNAPPE-II 9-Item Physiologic + Perinatal Score (0–162)
Sums grouped physiologic and perinatal SNAPPE-II subscores B2:B6 after verifying non-negativity.
=IF(MIN(B2:B6) < 0, "Subscores Cannot Be Negative", SUM(B2:B6))Richardson (2001) All-Birthweight NICU Mortality Probability (%)
Evaluates 100 / (1 + EXP(-(-5.188 + 0.0632 * SUM(B2:B6)))).
=IF(MIN(B2:B6) < 0, "Subscores Cannot Be Negative", ROUND(100 / (1 + EXP(-(-5.188 + 0.0632 * SUM(B2:B6)))), 2))Try the example
Use the original values or change them to test your understanding.