Emergency and Critical Care

SOFA Score Calculator (Sequential Organ Failure Assessment)

Assessment of multiorgan dysfunction (sepsis, ICU)

Primary source: Vincent JL et al. Intensive Care Med 1996; 22: 707-710. Singer M et al. JAMA 2016 (Sepsis-3)

Aleksandr A. Aulov, MD, internal medicine Last clinical review: April 28, 2026

Online calculation

Respiration (PaO₂/FiO₂, mm Hg)

Coagulation (platelets, ×10³/µL)

Liver (bilirubin, µmol/L)

Cardiovascular system

CNS (Glasgow Coma Scale)

Renal (creatinine, µmol/L)

About this score

SOFA (Sequential Organ Failure Assessment) is the standard scale for grading organ dysfunction in critically ill patients in the ICU. Developed by J.-L. Vincent et al. (Intensive Care Med, 1996). It evaluates six systems: respiratory (PaO₂/FiO₂), coagulation (platelets), liver (bilirubin), cardiovascular (blood pressure and vasopressor requirement), CNS (GCS), and renal (creatinine or urine output). Each system scores 0-4 points, for a total of 0-24.

With the Sepsis-3 consensus (2016), SOFA became central to the diagnosis of sepsis: sepsis = suspected infection + an increase in SOFA of ≥ 2 points from baseline. Septic shock additionally requires vasopressor support to maintain SBP ≥ 65 mm Hg and lactate > 2 mmol/L despite adequate fluid resuscitation.

The scale is used daily in the ICU to track the trajectory of organ dysfunction and evaluate response to treatment. International sepsis guidelines recommend SOFA as the standard tool in the critical care setting.

When to use

Patient in the ICU — daily monitoring of organ dysfunction.
Diagnosing sepsis per Sepsis-3 criteria when infection is suspected.
Predicting outcome in critically ill patients — each point increase is associated with higher mortality.
Documenting the trajectory during treatment and justifying escalation of care (mechanical ventilation, dialysis, vasopressors).

Clinical example

Case

58-year-old man, day 3 in the ICU with pneumonia. PaO₂/FiO₂ 180 (on mechanical ventilation, FiO₂ 0.5). Platelets 80×10⁹/L. Bilirubin 45 µmol/L. On norepinephrine 0.1 µg/kg/min to maintain SBP. GCS 13 (sedation). Creatinine 180 µmol/L.

Calculation

Respiration (P/F 180 on mechanical ventilation — 3) + Coagulation (platelets 80 — 2) + Liver (bilirubin 45 — 1) + Cardiovascular (norepinephrine ≤ 0.1 — 3) + CNS (GCS 13 — 1) + Renal (creatinine 180 — 2) = 12 points.

Interpretation and management

Severe multiorgan dysfunction. Predicted mortality ~50%. Approach: optimize mechanical ventilation, consider renal replacement therapy if creatinine rises or oliguria/anuria develops, continue vasopressor support, correct coagulopathy. Reassess daily — an increase of ≥ 2 points from baseline indicates further deterioration.

Limitations and cautions

Requires laboratory data — not suitable for the emergency department or prehospital setting (qSOFA is used there).
Sedation distorts assessment of the CNS component.
Chronic conditions (CKD on hemodialysis, baseline thrombocytopenia) produce a 'high baseline' SOFA — it is important to assess the delta, not the absolute value.
Not specific to a single diagnosis — reflects overall organ dysfunction.

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Frequently asked questions

How does SOFA differ from qSOFA?

qSOFA is a screening tool for the prehospital setting and emergency department (3 clinical criteria). SOFA is a full assessment in the ICU using laboratory data (6 systems, 0-24 points).

What does 'delta SOFA ≥ 2' mean?

An increase in score of ≥ 2 points from baseline in a patient with infection = sepsis per Sepsis-3 criteria. If the baseline SOFA is unknown, it is assumed to be 0 in previously healthy patients.

How often should SOFA be recalculated in the ICU?

At least daily. In case of acute deterioration, recalculate immediately after new labs and hemodynamic assessment are available.

What should be used for the CNS component in sedated patients?

If possible, assess during a sedation interruption (sedation vacation). If not possible, mark it as 'N/A' and exclude this component from the SOFA delta.

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Aleksandr A. Aulov Physician, internal medicine, Sechenov School — independent medical education platform. Calculators are compiled from the original publications and current clinical guidelines. Interpretation thresholds follow the source study unless stated otherwise.

This calculator is intended for healthcare professionals. Do not use it for self-diagnosis or self-treatment. Management decisions are made by the treating clinician based on the full clinical picture of the individual patient.