π¨ Sepsis Risk Screener
SIRS plus qSOFA plus Sepsis-3, in one screen.
For informational purposes only, not medical advice. Consult a healthcare professional.
Sepsis-3 defines sepsis as life-threatening organ dysfunction caused by a dysregulated host response to infection, identified by an acute rise in SOFA score of 2 or more with suspected infection. Septic shock adds persistent hypotension needing vasopressors plus lactate over 2 despite fluids. At the bedside, SIRS criteria catch early inflammation and qSOFA flags high-risk patients without waiting for labs. This screener combines all three frameworks into one assessment with a clear recommendation, for education and clinical reference.
How to Use This Calculator
Confirm suspected infection, then check the SIRS and qSOFA criteria present plus any shock features. The screener synthesizes the Sepsis-3 picture.
Establish suspected infection first. Without it, these criteria describe inflammation, not sepsis.
Check the four SIRS items and three qSOFA items from vitals, labs, and mental status.
Add lactate and vasopressor status. The combination stages the result from monitor to septic shock.
How the Math Works
Count SIRS criteria: temperature over 38 or under 36, heart rate over 90, respiratory rate over 20 or PaCO2 under 32, WBC over 12,000 or under 4,000 or bands over 10 percent. Two or more is SIRS-positive. Count qSOFA: respiratory rate 22 plus, systolic 100 or less, GCS under 15; 2 or more is high risk. Sepsis-3 logic: suspected infection plus organ dysfunction (qSOFA 2+ as the bedside proxy, full SOFA confirming) equals sepsis; adding vasopressor-dependent hypotension with lactate over 2 equals septic shock. The screener reports SIRS status, qSOFA, and the Sepsis-3 stage together because each answers a different question.
Worked Example
A patient with suspected urinary infection, fever, tachycardia, tachypnea, and new confusion has 3 / 4 (positive) SIRS criteria and a qSOFA of 2. The calculator stages this as High risk: likely sepsis (Sepsis-3 concept): infection with bedside organ dysfunction, meeting the Sepsis-3 concept of sepsis pending full SOFA confirmation. That staging triggers the bundle: cultures, broad-spectrum antibiotics, fluids, and lactate, without waiting for the lab-based score.
Reading Your Result
Infection with SIRS under 2 and qSOFA under 2 is lower risk: treat the infection and monitor. SIRS 2+ with infection is systemic inflammation needing prompt antibiotics and watching for organ dysfunction. qSOFA 2+ with infection is high risk: escalate, measure lactate, and start the sepsis bundle. Adding vasopressor-dependent hypotension with high lactate is septic shock: ICU, aggressive resuscitation, and source control. The stages escalate care; none of them waits for perfect information.
| Stage | Criteria | Response |
|---|---|---|
| Infection, low risk | SIRS under 2, qSOFA under 2 | Treat, monitor |
| Systemic inflammation | SIRS 2+ | Prompt antibiotics |
| High risk / sepsis | qSOFA 2+ | Sepsis bundle, escalate |
| Septic shock | + vasopressors + lactate over 2 | ICU resuscitation |
Limitations
Bedside proxies are not the SOFA score: full organ dysfunction assessment needs labs including platelets, bilirubin, creatinine, and PaO2. SIRS is nonspecific and qSOFA insensitive early, so clinical suspicion outranks both. This screener educates and prompts; sepsis management follows institutional protocols and the surviving sepsis campaign bundles, not a web tool.
Related Calculators
Related tools: qSOFA sepsis score shock index calculator revised trauma score calculator.
For informational purposes only, not medical advice. Consult a healthcare professional.
Frequently Asked Questions
What is sepsis?
Life-threatening organ dysfunction caused by a dysregulated response to infection. Sepsis-3 defines it as suspected infection plus an acute SOFA increase of 2 or more. It is the body own response damaging its tissues, not the infection alone.
What is the difference between sepsis and septic shock?
Septic shock is sepsis with persistent hypotension requiring vasopressors to maintain MAP 65+ plus lactate over 2 despite fluids. It carries substantially higher mortality, around 30 to 40 percent. Shock is sepsis at its most severe, not a separate disease.
What are SIRS criteria?
Temperature over 38 or under 36, heart rate over 90, respiratory rate over 20 or low PaCO2, WBC over 12,000 or under 4,000 or high bands. Two or more define SIRS. Sensitive but nonspecific: many non-infectious conditions meet them.
Why did Sepsis-3 move away from SIRS?
Because SIRS missed the point: it describes inflammation, while organ dysfunction predicts death. Most ICU patients meet SIRS without infection. Sepsis-3 anchored the definition to SOFA-measured organ dysfunction, which tracks mortality far better.
What is the sepsis bundle?
The time-critical actions: measure lactate, draw blood cultures before antibiotics, give broad-spectrum antibiotics quickly, start fluids for hypotension or high lactate, and add vasopressors if needed. The one-hour bundle compresses these into the first hour of recognition.
How fast should antibiotics start in sepsis?
As soon as possible after recognition, ideally within the first hour. Each hour of delay in septic shock raises mortality in observational data. Cultures come first but must not delay the first dose meaningfully.
What lactate level matters?
Over 2 mmol/L signals hypoperfusion and enters the septic shock definition; over 4 has traditionally triggered aggressive resuscitation. Lactate clearance over hours guides therapy better than any single value.
Can sepsis happen without fever?
Yes. Elderly and immunocompromised patients often present hypothermic or afebrile, and absence of fever never excludes sepsis. Altered mentation or unexplained hypotension in a possible infection deserves the same urgency.
What is the SOFA score?
Sequential Organ Failure Assessment: six organ systems scored 0 to 4 from labs and vitals, total 0 to 24. The Sepsis-3 diagnostic standard uses an acute rise of 2 or more. qSOFA is its bedside screening cousin.
How can sepsis be prevented?
Vaccination, prompt treatment of infections, wound care, and hand hygiene reduce the infections that lead to sepsis. For high-risk patients, early warning systems and rapid response teams catch deterioration sooner. There is no sepsis vaccine; prevention targets the infections behind it.