Reference — Critical Care
SOFA Score Reference
Sequential Organ Failure Assessment (SOFA) — 6 organ systems, scoring criteria, Sepsis-3 definitions for sepsis and septic shock, qSOFA rapid bedside screening tool, score interpretation, and nursing implications for ICU and critical care settings.
Critical Care · ICU
Educational use only. SOFA scoring is used in clinical assessment and research settings. Apply Sepsis-3 criteria with clinical context — SOFA is a tool for identifying organ dysfunction, not a definitive diagnostic test. Always consult institutional protocols. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Sepsis-3 Definitions
| Sepsis | Life-threatening organ dysfunction caused by a dysregulated host response to infection. Operationalized as suspected infection + acute increase in SOFA score ≥ 2 from baseline (representing organ dysfunction). |
| Septic shock | Sepsis WITH both: (1) vasopressor requirement to maintain MAP ≥ 65 mmHg AND (2) serum lactate > 2 mmol/L — DESPITE adequate volume resuscitation. Hospital mortality > 40%. |
| SOFA baseline | Baseline SOFA = 0 (assumed for patients without prior known organ dysfunction). A SOFA score increase of ≥ 2 from baseline = organ dysfunction = Sepsis-3 sepsis criteria. Previously healthy patients with SOFA ≥ 2 qualify. |
| Systemic Inflammatory Response Syndrome (SIRS) — historical | Pre-Sepsis-3 definition: 2+ of: fever/hypothermia, tachycardia, tachypnea, leukocytosis/leukopenia. Replaced by SOFA-based definition in Sepsis-3 (2016) — SIRS criteria are not sufficiently specific (can occur from non-infectious causes). SIRS still appears on NCLEX. |
SOFA Scoring — 6 Organ Systems
Each organ system is scored 0–4. Total range: 0–24. Higher scores = worse organ dysfunction = higher mortality. A score ≥ 2 in any domain from baseline = organ dysfunction present.
Respiratory — PaO₂/FiO₂ ratio (mmHg)
| Score 0 | Score 1 | Score 2 | Score 3 | Score 4 |
|---|---|---|---|---|
| ≥ 400 | 300–399 | 200–299 | 100–199 (with respiratory support) | < 100 (with respiratory support) |
SpO₂/FiO₂ can substitute when ABG not available. Normal PaO₂/FiO₂ = 400–500 mmHg on room air (21% O₂). Lower ratio = worse oxygenation.
Coagulation — Platelets (× 10³/µL)
| Score 0 | Score 1 | Score 2 | Score 3 | Score 4 |
|---|---|---|---|---|
| ≥ 150 | 100–149 | 50–99 | 20–49 | < 20 |
Platelet consumption from DIC, endothelial activation, and bone marrow suppression all contribute to coagulopathy in sepsis.
Liver — Bilirubin (mg/dL)
| Score 0 | Score 1 | Score 2 | Score 3 | Score 4 |
|---|---|---|---|---|
| < 1.2 | 1.2–1.9 | 2.0–5.9 | 6.0–11.9 | ≥ 12.0 |
Hyperbilirubinemia in sepsis reflects hepatic dysfunction, biliary stasis, and hemolysis. Jaundice is a late sign of hepatic organ failure.
Cardiovascular — MAP or vasopressor dose
| Score 0 | Score 1 | Score 2 | Score 3 | Score 4 |
|---|---|---|---|---|
| MAP ≥ 70 mmHg | MAP < 70 mmHg (no vasopressors) | Dopamine < 5 OR dobutamine (any dose) | Dopamine 5.1–15 OR epinephrine ≤ 0.1 OR norepinephrine ≤ 0.1 (µg/kg/min) | Dopamine > 15 OR epinephrine > 0.1 OR norepinephrine > 0.1 (µg/kg/min) |
Vasopressor requirement (score ≥ 2) is the cardiovascular criterion for septic shock. Scores 3–4 reflect refractory vasodilatory shock.
CNS (Neurological) — Glasgow Coma Scale (GCS)
| Score 0 | Score 1 | Score 2 | Score 3 | Score 4 |
|---|---|---|---|---|
| 15 (normal) | 13–14 | 10–12 | 6–9 | < 6 |
GCS is the standardized CNS component. Altered mental status is also one of the 3 qSOFA criteria. Sedation and analgesic effects must be considered when interpreting GCS in ICU patients.
Renal — Creatinine (mg/dL) or urine output
| Score 0 | Score 1 | Score 2 | Score 3 | Score 4 |
|---|---|---|---|---|
| Cr < 1.2 | Cr 1.2–1.9 | Cr 2.0–3.4 | Cr 3.5–4.9 OR UO < 500 mL/day | Cr ≥ 5.0 OR UO < 200 mL/day |
Urine output criterion can be used when creatinine not available. AKI (KDIGO stage 2–3) reliably correlates with SOFA renal scores 3–4.
SOFA Score Interpretation
| Total Score | Approximate ICU Mortality | Clinical Context |
|---|---|---|
| 0–1 | < 10% | Normal or minimal organ dysfunction. Low sepsis mortality risk. |
| 2–3 | 10–20% | Sepsis-level organ dysfunction. Sepsis-3 sepsis criteria met with change from baseline ≥ 2. |
| 4–5 | 20–30% | Multi-system involvement. ICU admission and aggressive management required. |
| 6–9 | 30–50% | Significant multi-organ dysfunction. High risk of poor outcome. |
| ≥ 10 | > 50–80%+ | Severe MODS (multiple organ dysfunction syndrome). Extremely high mortality. Goals-of-care discussion often appropriate. |
Mortality estimates are approximate and vary by patient population, comorbidities, and institution. SOFA is a tool for clinical assessment and research — not a definitive mortality predictor for individual patients.
qSOFA — Quick Bedside Screening Tool
qSOFA is designed for OUTSIDE the ICU (ED, floor, step-down) — uses only bedside clinical parameters, requires no labs. A positive qSOFA (≥ 2/3 criteria) should prompt further assessment and SOFA scoring.
| qSOFA Criterion | Threshold | Score (if present) |
|---|---|---|
| Altered mental status | GCS < 15 (new confusion, agitation, decreased LOC) | +1 |
| Respiratory rate | RR ≥ 22 breaths/min | +1 |
| Systolic blood pressure | SBP ≤ 100 mmHg | +1 |
qSOFA ≥ 2/3 = prompt comprehensive sepsis evaluation (full SOFA, blood cultures, lactate, CBC, CMP). qSOFA is a SCREENING tool — a negative qSOFA does NOT rule out sepsis. Use clinical judgment with any signs of infection.
Nursing Applications
| Floor / ED screening | Apply qSOFA at bedside for any patient with suspected infection. qSOFA ≥ 2 = notify provider, begin sepsis workup, obtain blood cultures before antibiotics, check lactate. Time to antibiotics is critical — target < 1 hour from sepsis recognition. |
| ICU trending | Serial SOFA every 24–48 hours to trend trajectory. Improving SOFA = responding to treatment. Worsening SOFA = organ failure progression. Document organ function trends in nursing notes. |
| Vasopressor documentation | Document vasopressor type, dose, and MAP response hourly. Cardiovascular SOFA scoring requires vasopressor dose data — maintain accurate titration records. |
| Urine output tracking | Hourly urine output is a renal SOFA data point. UO < 500 mL/day = SOFA renal score 3. UO < 200 mL/day = score 4. Strict hourly I&O mandatory in sepsis patients. |
NCLEX Pearls
Sepsis-3 sepsis = suspected infection + SOFA ≥ 2 from baseline (organ dysfunction). SIRS criteria are historical — Sepsis-3 uses SOFA.
Septic shock = sepsis + vasopressor need (MAP ≥ 65) + lactate > 2 mmol/L despite adequate fluids. Hospital mortality > 40%.
qSOFA uses 3 bedside criteria (no labs): altered mental status + RR ≥ 22 + SBP ≤ 100. Score ≥ 2 = sepsis concern.
SOFA cardiovascular score 2 = dopamine < 5 OR dobutamine (any dose). Score 3–4 = higher vasopressor doses (norepinephrine, epinephrine, dopamine > 5).
SOFA respiratory = PaO₂/FiO₂ ratio (not PaO₂ alone). Normal ≈ 400+. ARDS: PaO₂/FiO₂ < 300.
qSOFA is a SCREENING tool — a negative qSOFA does NOT rule out sepsis. Clinical judgment always applies.
Related Resources
Standards & sources
Fact-checked Jun 20, 2026This page is written to align with Society of Critical Care Medicine (SCCM) · Surviving Sepsis Campaign · American Association of Critical-Care Nurses (AACN). It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →