Sepsis Calculator (qSOFA Score)

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. It is one of the leading causes of death in intensive care units worldwide. Early recognition and treatment dramatically improve outcomes.

The qSOFA score (quick Sequential Organ Failure Assessment) was introduced as part of the Sepsis-3 definitions in 2016. It uses three bedside criteria requiring no laboratory tests:

1. Respiratory rate of 22 or more breaths per minute (+1 point)
2. Altered mentation, meaning any change in the Glasgow Coma Scale from baseline (+1 point)
3. Systolic blood pressure of 100 mmHg or below (+1 point)

A score of 2 or higher suggests the patient may have sepsis and is at higher risk for prolonged ICU stay or in-hospital death. Sensitivity is lower than the full SOFA score, but qSOFA can be assessed instantly at the bedside without waiting for labs.

The qSOFA is a screening tool, not a diagnostic criterion. Its role is to prompt further evaluation: blood cultures, lactate measurement, imaging, and the complete SOFA score. A patient with qSOFA of 1 is not necessarily low risk.

That last point deserves more weight than it usually gets. The 2021 Surviving Sepsis Campaign guidelines recommend against using qSOFA as a single screening tool compared with SIRS, NEWS, or MEWS, precisely because its sensitivity is poor. It is good at telling you a patient is in trouble and bad at telling you one is not. Treat a negative screen as uninformative rather than reassuring.

Enter the measured respiratory rate and systolic pressure rather than deciding in advance whether each one crosses its threshold. Where a value sits close to the line, the calculator says so, because a patient at 21 breaths a minute and 102 mmHg scores zero and can be an hour of drift away from scoring two.

Once sepsis is suspected, the Surviving Sepsis Campaign guidelines recommend:

• Blood cultures before antibiotics
• Broad-spectrum antibiotics within 1 hour where shock is present or sepsis is highly likely, and within 3 hours where sepsis is possible but not certain
• 30 mL/kg crystalloid bolus for hypotension or lactate >= 4 mmol/L
• Vasopressors if MAP (mean arterial pressure) remains below 65 mmHg after fluids

Septic shock is defined as sepsis with a vasopressor requirement to hold mean arterial pressure at 65 mmHg or above, plus a lactate above 2 mmol/L that persists despite adequate fluid resuscitation. Both halves matter: the lactate has to survive the fluids. In-hospital mortality for septic shock exceeds 40% in most cohorts.

This calculator is a clinical decision support tool only. It does not replace physician judgment.