Free Sepsis Calculator

Sepsis Screening with the qSOFA Score

This free online sepsis screening tool is built upon the Sepsis-3 criteria and serves as a qSOFA score calculator to aid in the early detection of sepsis. By delivering a quick SOFA assessment, it helps clinicians stratify patients based on their risk of organ dysfunction and in‑hospital mortality, making it an essential part of sepsis risk assessment.

Defining Sepsis

Sepsis is a syndrome triggered by a dysregulated host response to infection, resulting in life‑threatening organ dysfunction. It remains a leading cause of death from infection worldwide, even with modern vaccines and antibiotics. The critical difference between an uncomplicated infection and sepsis lies in the presence of abnormal immune regulation and concurrent organ failure.

Sepsis-3 Diagnostic Criteria

The Third International Consensus (Sepsis‑3) introduced a two‑stage screening strategy to identify patients with suspected infection who are at high risk.

Stage 1 — Quick SOFA (qSOFA)

The qSOFA score can be obtained rapidly at the bedside without laboratory tests. It uses three clinical indicators:

• Altered mental status (e.g., Glasgow Coma Scale below 15)
• Systolic blood pressure $\leq 100\ \text{mmHg}$
• Respiratory rate $\geq 22/\text{min}$

Each indicator contributes 1 point. A qSOFA score of 2 or more signals a high likelihood of prolonged ICU stay or in‑hospital death and should prompt an evaluation for organ dysfunction.

Stage 2 — SOFA Score

Organ dysfunction is defined as an acute increase of 2 or more points in the SOFA (Sequential Organ Failure Assessment) score from baseline (assumed zero in patients without prior organ failure). The SOFA score assesses six organ systems:

• Respiratory: PaO₂/FiO₂ ratio
• Neurological: Glasgow Coma Scale
• Cardiovascular: Mean arterial pressure or need for vasopressors
• Renal: Serum creatinine or urine output
• Hepatic: Bilirubin level
• Coagulation: Platelet count

If the SOFA score change is 2 or more after infection, the patient meets the Sepsis‑3 definition of sepsis.

Septic Shock Criteria

Septic shock, a severe subset of sepsis, dramatically increases mortality. According to Sepsis‑3, it requires:

1. Meeting sepsis criteria (infection + ΔSOFA of 2 or more).
2. Persistent hypotension that mandates vasopressors to keep mean arterial pressure $\gt 65\ \text{mmHg}$.
3. Serum lactate $\gt 2\ \text{mmol/L}$ (or $\gt 18\ \text{mg/dL}$) despite adequate fluid resuscitation.

The presence of all three criteria is linked to an in‑hospital mortality rate above 40%.

Clinical Implications & Limitations

Neither qSOFA nor SOFA should be viewed as absolutes for diagnosing sepsis. A score below 2 does not exclude infection or justify delaying therapy; these tools are designed to prompt, not replace, clinical judgment. The strength of qSOFA lies in its simplicity—it can be performed in minutes without blood draws, enabling early suspicion. Once flagged, laboratory investigations are needed to confirm organ dysfunction.

This sepsis calculator is derived from the Sepsis‑3 consensus and aims to provide consistent, rapid assessments. It is intended as an educational and screening aid, not as a substitute for professional medical advice. Always consult a qualified healthcare provider for diagnosis and treatment decisions.