Sepsis is one of the leading causes of in-hospital mortality worldwide. It is estimated to affect more than 49 million people per year and causes around 11 million deaths — more than breast, colon, and prostate cancer combined. However, early detection and timely treatment can dramatically reduce this mortality.
In 2016, the Sepsis-3 consensus redefined the concept of sepsis and proposed two screening tools that are now standard in clinical practice: qSOFA for rapid detection outside the ICU, and SOFA for quantifying organ dysfunction.
What is sepsis? The Sepsis-3 definition
According to the current definition (Sepsis-3, 2016), sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. This definition eliminated the previous concept of SIRS (Systemic Inflammatory Response Syndrome) as a diagnostic criterion, as it was considered too non-specific.
qSOFA: rapid screening outside the ICU
The quick SOFA (qSOFA) is a rapid screening tool designed to identify patients with suspected infection who have a higher risk of deterioration outside the ICU — in the emergency department, general ward, or prehospital setting.
It evaluates only three clinical criteria, with no laboratory tests required:
| Criterion | Positive value | Points |
|---|---|---|
| Respiratory rate | ≥ 22 breaths/min | 1 |
| Altered mental status | Glasgow < 15 (or any acute change) | 1 |
| Systolic blood pressure | ≤ 100 mmHg | 1 |
Interpretation: A qSOFA ≥ 2 points identifies patients with higher risk of mortality and clinical deterioration. This result should prompt a full SOFA assessment and consideration of ICU transfer.
SOFA: quantifying organ dysfunction
The SOFA score (Sequential Organ Failure Assessment) evaluates the degree of dysfunction across six organ systems. It is primarily used in the ICU but also in the emergency department for confirmed or suspected sepsis patients.
| System | Parameter | Points (0–4) |
|---|---|---|
| Respiratory | PaO₂/FiO₂ (mmHg) | >400=0 · 301-400=1 · 201-300=2 · 101-200=3 · ≤100=4 |
| Coagulation | Platelets (×10³/µL) | >150=0 · 101-150=1 · 51-100=2 · 21-50=3 · ≤20=4 |
| Hepatic | Bilirubin (mg/dL) | <1.2=0 · 1.2-1.9=1 · 2.0-5.9=2 · 6.0-11.9=3 · ≥12=4 |
| Cardiovascular | MAP or vasopressors | MAP≥70=0 · MAP<70=1 · Dopamine≤5=2 · Dopamine>5=3 · Norepinephrine>0.1=4 |
| Neurological | Glasgow Coma Scale | 15=0 · 13-14=1 · 10-12=2 · 6-9=3 · <6=4 |
| Renal | Creatinine (mg/dL) or urine output | <1.2=0 · 1.2-1.9=1 · 2.0-3.4=2 · 3.5-4.9=3 · >5=4 |
Interpretation: Sepsis is defined by an acute increase of ≥ 2 points in SOFA from baseline (assuming 0 in patients without prior organ dysfunction). Higher scores correlate with higher expected mortality:
- SOFA 0–6: mortality < 10%
- SOFA 7–9: mortality ~15–20%
- SOFA ≥ 11: mortality > 50%
qSOFA vs. SOFA: when to use each?
| qSOFA | SOFA | |
|---|---|---|
| Setting | Outside ICU (ED, ward) | ICU, ED with lab access |
| Lab required | No | Yes |
| Calculation time | Seconds | 3–5 minutes |
| Purpose | Rapid screening | Diagnosis and prognosis |
| Alert threshold | ≥ 2 points | Increase ≥ 2 from baseline |
Response to sepsis: the golden hour
Upon suspicion of sepsis, the first-hour management protocol includes:
- Draw blood cultures (at least 2 sets) before starting antibiotics.
- Measure serum lactate (elevated > 2 mmol/L indicates hypoperfusion).
- Broad-spectrum antibiotics within the first hour of diagnosis.
- Fluid resuscitation: 30 mL/kg of crystalloids in the first 3 hours if hypotension or lactate > 4 mmol/L.
- Continuous vital sign monitoring and hourly urine output.
Conclusion
qSOFA and SOFA are complementary tools that, used correctly, allow identification of septic patients before deterioration becomes irreversible. qSOFA triggers the alarm in seconds; SOFA confirms and quantifies the severity. In sepsis, every minute counts — and having these tools at hand can make the difference between life and death.