This sequential organ failure assessment (SOFA) score calculator evaluates and predicts ICU mortality based on clinical data. Discover more about the score, the answer choices for the variables and the result interpretation below the form.
How does this Sequential Organ Failure Assessment (SOFA) score calculator work?
This is a health tool that assesses clinical data of the intensive care unit patient in order to determine mortality rate. The score for morbidity severity is calculated at admission and monitored every 24 hours until the patient is discharged.
The clinical assessor is advised to input the worst value in the determinations from the last 24 hours. This score tries to check the condition and the degree of dysfunction in 6 of the body systems:
■ respiratory;
■ cardiovascular;
■ hepatic;
■ coagulation;
■ renal;
■ neurological.
SOFA is the acronym of Sequential Organ Failure Assessment and defines the type of evaluation that occurs when checking the following variables that were chosen by the European Society of Intensive Care Medicine:
■ PaO2/FiO2 – partial oxygen pressure or fraction of inhaled O2 – used to evaluate the state of the Platelet Count (×103/µL) – state of blood composition and coagulation.
■ Glasgow Coma Scale – assessment of the patient’s level of consciousness and reaction to pain, voice and movement. According to the GCS points, there is given the SOFA number of points.
■ Bilirubin (mg/dL / µmol/L) – evaluating the metabolic state of the body and the work of the liver.
■ Mean arterial pressure and whether there is hypotension present or the patient is under any medication to relieve pressure on the circulatory system.
■ Creatinine – checking the filtration function of the kidneys.
| Variable / Points | 0 | 1 | 2 | 3 | 4 |
| PaO2/FiO2 (mmHg) | < 400 | < 300 | < 200 | <100 | |
| Platelet Count (×103/µL) | < 150 | < 100 | < 50 | < 20 | |
| Glasgow Coma Scale | 13 – 14 | 10 – 12 | 6 – 9 | <6 | |
| Bilirubin (mg/dL / µmol/L) | 1.2 – 1.9 / >20 – 32 | 2 – 5.9 / 33 – 101 | 6 – 11.9 / 102 – 204 | >12 / >204 | |
| MAP | No hypotension | MAP below 70 | On vasopressors, dopamine < 5 µg/kg/min or dobutamine (any dose) | Dopamine > 5 µg/kg/min or Epi/Norepi < 0.1 µg/kg/min | Dopamine > 15 µg/kg/min or Epi/Norepi > 0.1 µg/kg/min |
| Creatinine (mg/dL /µmol/L) | < 1.2 /< 106 | 1.2-1.9 /106-168 | 2.0-3.4 / 177-301 | 3.5-4.9 / 309-433 | 5.0 / > 442 |
SOFA score interpretation
Each of the answer choices in the 6 variables has assigned points from 0 (normal function) to 4 (high degree of dysfunction). This means that the overall score is between 0 and 24. The following table presents by comparison, the score categories and the associated mortality percentages.
| SOFA score | Mortality risk |
| 0 - 6 | <10% |
| 7 - 9 | 15 - 20% |
| 10 - 12 | 40 - 50% |
| 13 - 14 | 50 - 60% |
| 15 | >80% |
| 16 - 24 | >90% |
Similar to APACHE II, another ICU scoring system, this score is administered in admission but also for prognosis so this way, the SOFA score can help in monitoring the evolution of the patient, the progression of the condition and also stratify further negative outcome risks.
The score has performed well in validation studies with a good correlation between the result and the degree of dysfunction or organ failure in critically ill patients.
There was also observed a score trend in the first 48h after admission with patient in which the score would increase having an over 50% mortality risk, patients with unchanged results having between 27 and 35% mortality risk and patients in which the score was decreasing with a below 27% risk of negative outcome.
Another observation is related to the association between the SOFA score result and the length of stay in the ICU of patient with cardiovascular disorders. At a first glace, survival rates were higher in patients with SOFA scores of below 6. Some clinicians might even use the score in establishing or monitoring the effectiveness of therapeutic strategies.
References
1) Vincent JL, Moreno R, Takala J, Willatts S, De Mendonça A, Bruining H, Reinhart CK, Suter PM, Thijs LG. (1996) The SOFA (Sepsis-related Organ Failure Assessment) score to describe organ dysfunction/failure. On behalf of the Working Group on Sepsis-Related Problems of the European Society of Intensive Care Medicine. Intensive Care Med; 22(7):707-10.
2) Vincent JL, de Mendonça A, Cantraine F, Moreno R, Takala J, Suter PM, Sprung CL, Colardyn F, Blecher S. (1998) Use of the SOFA score to assess the incidence of organ dysfunction/failure in intensive care units: results of a multicenter, prospective study. Working group on "sepsis-related problems" of the European Society of Intensive Care Medicine. Crit Care Med; 26(11):1793-800.
3) Ferreira FL, Bota DP, Bross A, Mélot C, Vincent JL. (2001) Serial evaluation of the SOFA score to predict outcome in critically ill patients. JAMA; 286(14):1754-8.
26 Sep, 2015