Total SOFA-2 score = sum of six organ-system scores (0–4 points each; range 0–24). When multiple criteria apply within a domain, use the highest point value.

Organ-system definitions (SOFA-2):

Organ system	0 points	1 point	2 points	3 points	4 points
Brain (neurological)	GCS 15 or able to follow simple motor commands; no drugs needed for delirium.	GCS 13–14 or localises pain, or requires medication to treat delirium.	GCS 9–12 or withdrawal to pain.	GCS 6–8 or flexion to pain.	GCS 3–5, or extension/no response to pain, or generalised myoclonus.
Respiratory	PaO₂:FiO₂ >300 mmHg (>40 kPa).	PaO₂:FiO₂ ≤300 mmHg (≤40 kPa).	PaO₂:FiO₂ ≤225 mmHg (≤30 kPa).	PaO₂:FiO₂ ≤150 mmHg (≤20 kPa) with advanced ventilatory support (HFNO, CPAP/BiPAP/NIV, invasive or long-term home ventilation).	PaO₂:FiO₂ ≤75 mmHg (≤10 kPa) with advanced ventilatory support or ECMO.
Cardiovascular	MAP ≥70 mmHg, no vasopressor or inotrope.	MAP <70 mmHg, no vasopressor or inotrope.	Low-dose vasopressor: sum of norepinephrine+adrenaline ≤0.2 µg/kg/min, or any dose of another vasopressor or inotrope.	Medium-dose vasopressor: sum of norepinephrine+adrenaline >0.2–≤0.4 µg/kg/min, or low-dose norepinephrine/adrenaline plus another vasopressor or inotrope.	High-dose vasopressor: sum of norepinephrine+adrenaline >0.4 µg/kg/min, or medium-dose norepinephrine/adrenaline plus another vasopressor/inotrope, or mechanical circulatory support (eg VA-ECMO, IABP, LVAD).
Haemostasis (platelets)	>150 ×10³/µL (>150 ×10⁹/L).	101–150 ×10³/µL (101–150 ×10⁹/L).	81–100 ×10³/µL (81–100 ×10⁹/L).	51–80 ×10³/µL (51–80 ×10⁹/L).	≤50 ×10³/µL (≤50 ×10⁹/L).
Liver (total bilirubin)	≤1.20 mg/dL (≤21 µmol/L).	>1.20–≤3.0 mg/dL (>21–≤51 µmol/L).	>3.0–≤6.0 mg/dL (>51–≤103 µmol/L).	>6.0–≤12.0 mg/dL (>103–≤205 µmol/L).	>12.0 mg/dL (>205 µmol/L).
Kidney (creatinine / urine output / RRT)	Serum creatinine ≤1.20 mg/dL (≤110 µmol/L) and no oliguria.	Serum creatinine ≤2.0 mg/dL (≤170 µmol/L), or urine output <0.5 mL/kg/h for 6–12 h.	Serum creatinine ≤3.50 mg/dL (≤300 µmol/L), or urine output <0.5 mL/kg/h for ≥12 h.	Serum creatinine >3.50 mg/dL (>300 µmol/L), or urine output <0.3 mL/kg/h for ≥24 h, or anuria for ≥12 h.	Receiving or meeting criteria for renal replacement therapy (including chronic maintenance therapy).

Sequential Organ Failure Assessment (SOFA)-2 Score