SAPS II Score Calculator
Simplified Acute Physiology Score II – ICU Mortality Prediction
The Simplified Acute Physiology Score II (SAPS II) is a severity-of-disease classification system used in intensive care units to predict hospital mortality risk.
SAPS II uses 17 variables collected within the first 24 hours of ICU admission to generate a score (0-163) and predicted mortality percentage.
SAPS II Calculator
Clinical Interpretation
Based on the calculated SAPS II score, the patient has a low predicted mortality risk.
Risk Stratification
Low Risk Category
SAPS II Mortality Risk
About SAPS II
- Purpose
- To predict hospital mortality risk for ICU patients based on physiological parameters.
- Variables
- 17 parameters including age, type of admission, chronic diagnoses, and physiological measurements.
- Scoring Range
- 0 to 163 points, with higher scores indicating greater severity.
- Calculation
- Points are assigned for each variable based on deviation from normal values.
- Mortality Prediction
- Uses logistic regression equation to convert score to predicted mortality percentage.
Important: SAPS II is a prognostic tool and should not be used as the sole basis for clinical decisions. Always consider the individual patient’s overall clinical picture and response to treatment.
SAPS II Scoring System
| Variable | Range | Points |
|---|---|---|
| Age | <40 to ≥80 years | 0 to 17 |
| Heart Rate | <40 to ≥160 bpm | 0 to 11 |
| Systolic BP | <70 to ≥200 mmHg | 0 to 13 |
| Temperature | <30 to ≥41°C | 0 to 6 |
| PaO2/FiO2 | <100 to ≥400 mmHg | 0 to 11 |
| Urine Output | <0.5 to ≥1.0 L/24h | 0 to 11 |
| Serum Urea | <28 to ≥84 mg/dL | 0 to 10 |
| WBC | <1.0 to ≥20.0 ×10³/μL | 0 to 6 |
| Potassium | <3.0 to ≥5.0 mmol/L | 0 to 9 |
| Sodium | <125 to ≥145 mmol/L | 0 to 5 |
| Bicarbonate | <15 to ≥20 mmol/L | 0 to 6 |
| Bilirubin | <4 to ≥6 mg/dL | 0 to 9 |
| Glasgow Coma Score | 3 to 15 | 0 to 26 |
| Admission Type | Medical/Scheduled/Unsurgical | 0 to 8 |
| Chronic Diagnoses | AIDS, Hematologic malignancy, Metastatic cancer | 0 to 17 |
The Simplified Acute Physiology Score II (SAPS II) is a severity-of-disease classification system used in intensive care units (ICUs) to predict hospital mortality risk. Developed in 1993, it uses 17 variables collected within the first 24 hours of ICU admission:
- 12 physiology variables (vital signs, lab values)
- Age
- Type of admission (medical, scheduled surgical, unscheduled surgical)
- 3 chronic disease variables (AIDS, hematologic malignancy, metastatic cancer)
SAPS II provides:
- A score from 0 to 163 (higher scores indicate greater severity)
- A predicted mortality percentage using logistic regression
- Objective assessment of ICU patient severity
- Comparison of ICU performance across institutions

