What is the SOFA Score?
The Sequential Organ Failure Assessment (SOFA) score is a clinical tool used in intensive care units worldwide to quantify the degree of organ dysfunction in critically ill patients. It evaluates six organ systems — respiration, coagulation, liver, cardiovascular, central nervous system, and renal — assigning each a subscore from 0 (normal function) to 4 (severe failure). The total ranges from 0 to 24, with higher scores associated with greater morbidity and mortality. This calculator is for educational and clinical decision-support purposes and does not replace professional judgment.
How to Use the Calculator
For each of the six organ systems, select the option that matches your patient's most abnormal recorded value during the assessment period (typically the worst value in a 24-hour window). The calculator adds the six subscores to produce a total SOFA score and shows an approximate ICU mortality band associated with that score.
The Formula Explained
The score is a simple sum: $$\text{SOFA} = \text{Resp} + \text{Coag} + \text{Liver} + \text{CV} + \text{CNS} + \text{Renal}$$ Each component is scored against published thresholds — for example, the respiratory subscore uses the PaO₂/FiO₂ ratio, the coagulation subscore uses platelet count, the liver subscore uses bilirubin, and the renal subscore uses creatinine or urine output. The cardiovascular subscore depends on mean arterial pressure and vasopressor doses, while the CNS subscore uses the Glasgow Coma Scale.
Worked Example
Consider a patient with PaO₂/FiO₂ < 200 on support (Resp = 3), platelets < 100 (Coag = 2), bilirubin 2.0–5.9 (Liver = 2), MAP < 70 (CV = 1), GCS 10–12 (CNS = 2), and creatinine 2.0–3.4 (Renal = 2). The total SOFA = $$3 + 2 + 2 + 1 + 2 + 2 = 12 \text{ points}$$ placing the patient in a high-mortality band.
FAQ
What is a normal SOFA score? A score of 0 indicates no organ dysfunction. Scores rise as organ failure worsens.
Does a higher SOFA mean higher mortality? Yes — increasing scores and rising scores over time correlate with higher ICU mortality.
How is SOFA different from qSOFA? qSOFA is a rapid bedside screen using just three criteria, whereas the full SOFA score requires laboratory values and is more detailed.
