Printed on 3/17/2026
For informational purposes only. This is not medical advice.
The Sequential Organ Failure Assessment (SOFA) score quantifies the degree of organ dysfunction in six systems: respiratory (PaO₂/FiO₂), coagulation (platelets), liver (bilirubin), cardiovascular (MAP/vasopressors), neurological (GCS), and renal (creatinine/urine output). Each system is scored 0-4, yielding a total score of 0-24. Under the Sepsis-3 definitions, sepsis is defined as suspected infection with a SOFA score increase of 2 or more points. The SOFA score is widely used in ICU settings for prognostication, treatment decisions, and research. Higher scores correlate with increased mortality.
Formula: Total SOFA = Respiration + Coagulation + Liver + Cardiovascular + CNS + Renal (each 0-4). Range 0-24.
Collect PaO₂/FiO₂ ratio (respiratory), platelet count (coagulation), bilirubin (liver), MAP and vasopressor doses (cardiovascular), [Glasgow Coma Scale](/tools/glasgow-coma-scale) (neurological), and creatinine/urine output (renal).
Use the standardized thresholds to assign a score for each organ system. Higher scores indicate worse dysfunction. The cardiovascular component requires knowledge of specific vasopressor doses.
Sum all six components (range 0–24). Compare to baseline and prior scores. An increase of ≥2 points with suspected infection defines sepsis under Sepsis-3.
ICU physicians, hospitalists
Under Sepsis-3 definitions, sepsis is diagnosed when a patient with suspected infection has an acute SOFA increase of ≥2 points from baseline. This replaced older SIRS-based criteria.
Intensivists, palliative care teams
SOFA predicts ICU mortality and helps frame goals-of-care discussions. Serial SOFA trends over 48–96 hours are particularly powerful predictors of outcome.
Clinical researchers, trial investigators
SOFA is a standard endpoint in critical care trials. SOFA-free days, maximum SOFA, and delta-SOFA are commonly used outcomes that allow comparison across studies.
ICU nurses, trainees
Many ICUs calculate daily SOFA as part of structured rounds. Tracking trends helps identify patients who are improving versus those who are deteriorating.
Emergency physicians, rapid response teams
When qSOFA screening is positive (≥2 outside ICU), the full SOFA score confirms organ dysfunction and completes the sepsis diagnosis per Sepsis-3 criteria.
ICU directors, hospital administration
During surge periods or pandemics, SOFA has been used as part of crisis standards of care frameworks to guide allocation of scarce resources like ventilators.
An increasing SOFA over 48 hours predicts mortality up to 50%. A patient with initial SOFA 8 who improves to 4 has a much better prognosis than one who increases to 12. Trend is everything.
For patients without known pre-existing organ dysfunction, assume baseline SOFA = 0. For patients with chronic kidney disease, chronic liver disease, or chronic respiratory failure, use their chronic baseline values.
For patients on room air, FiO₂ = 0.21. For nasal cannula, estimate FiO₂ (each liter adds ~4% above 21%). Accuracy of the respiratory component depends on accurate FiO₂ documentation.
The cardiovascular subscore depends on specific vasopressor doses in mcg/kg/min. Ensure you're using the correct units and know the patient's weight for accurate dose calculation.
Sedated or paralyzed patients can't have their true [GCS](/tools/glasgow-coma-scale) assessed. Some protocols use the pre-sedation GCS; others score sedated patients as unable to assess. Know your institution's convention.
For the renal component, urine output <500 mL/day scores 3, and <200 mL/day scores 4. This requires accurate 24-hour urine measurement, not just spot checks.
GI failure, endocrine dysfunction, and immune status aren't scored. Two patients with SOFA 10 may have vastly different underlying conditions and prognoses.
In patients with pre-existing organ dysfunction (CKD, cirrhosis), calculate the change from their chronic baseline rather than assuming baseline 0. This gives a more accurate picture of acute deterioration.
A patient with infection but no organ dysfunction has infection, not sepsis. The SOFA increase is what distinguishes sepsis (life-threatening organ dysfunction) from uncomplicated infection.
qSOFA (3 bedside criteria) is for initial screening on wards. Full SOFA requires labs and is calculated in the ICU. They serve different purposes in different settings.
The SOFA score was developed by the European Society of Intensive Care Medicine in 1994–1996 (Vincent et al., Intensive Care Med 1996). It was incorporated into the Sepsis-3 definitions (Singer et al., JAMA 2016) as the criterion for organ dysfunction in sepsis. The Sepsis-3 task force chose SOFA because it is well-validated, objective, and can be calculated serially to track patient trajectory.
Your SOFA score quantifies the degree of organ dysfunction across six organ systems, with each system scored from 0 (normal function) to 4 (severe dysfunction). A total SOFA score of 0 to 1 indicates minimal or no organ dysfunction with an associated mortality of less than 3%. Scores of 2 to 6 suggest mild to moderate organ dysfunction with mortality ranging from approximately 10% to 20%.
Scores of 7 to 12 indicate significant multi-organ dysfunction with mortality rates of 30% to 50%, and scores of 13 or above are associated with mortality exceeding 50%. Under the Sepsis-3 definitions, an acute increase of 2 or more SOFA points from baseline in a patient with suspected infection constitutes a diagnosis of sepsis. A baseline SOFA of 0 is assumed for patients without known pre-existing organ dysfunction.
Beyond the total score, examining individual organ system scores provides valuable information about which organs are failing and may guide targeted interventions. For example, a high cardiovascular subscore indicates the need for vasopressor support, while a high renal subscore may prompt consideration of renal replacement therapy. The trend in SOFA scores over 24 to 96 hours is one of the strongest predictors of ICU outcome — an increasing SOFA over 48 hours is strongly associated with mortality.
The SOFA score should be calculated for all patients admitted to the ICU, at the time of admission and then every 24 hours throughout the ICU stay. It serves multiple purposes: establishing the severity of illness at admission, tracking the trajectory of organ dysfunction over time, diagnosing sepsis (when an acute SOFA increase of 2 or more occurs with suspected infection), and providing prognostic information to guide goals-of-care discussions.
The SOFA score should also be calculated when qSOFA screening is positive (score of 2 or more) in a patient with suspected infection outside the ICU, as the full SOFA score is required to confirm organ dysfunction and establish a sepsis diagnosis under Sepsis-3 criteria. It is also commonly used in clinical research as a standardized measure of organ dysfunction severity and as a primary or secondary outcome in critical care trials.
The SOFA score requires laboratory values (PaO2, platelets, bilirubin, creatinine) that may not be immediately available, limiting its use as a rapid bedside screening tool — this is why qSOFA was developed as a simpler initial screen. Some SOFA components may be difficult to assess in certain clinical situations: the respiratory component requires an arterial blood gas, the cardiovascular component requires knowledge of vasopressor doses, and urine output measurement requires a urinary catheter.
The SOFA score assumes a baseline of 0 for patients without known pre-existing organ dysfunction, which may not be accurate for patients with chronic kidney disease, chronic liver disease, or chronic respiratory failure. In these patients, the SOFA score may overestimate the degree of acute organ dysfunction. Some institutions calculate a delta-SOFA (change from baseline) to address this issue.
The SOFA score does not capture all aspects of critical illness. It does not assess gastrointestinal function, endocrine dysfunction, or immune status, and it does not account for the specific diagnosis or the reversibility of the underlying condition. Two patients with the same SOFA score may have vastly different prognoses depending on the etiology and trajectory of their illness. The SOFA score should be interpreted in the full clinical context and used alongside clinical judgment.
Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.
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