Clinical Score Calculators

SOFA Score

Sequential Organ Failure Assessment — diagnoses sepsis (SOFA ≥2) and predicts ICU mortality. Singer et al., JAMA 2016 (Sepsis-3).

Respiratory — PaO₂/FiO₂ (mmHg)

Coagulation — Platelets (×10³/µL)

Liver — Bilirubin (mg/dL)

Cardiovascular — MAP / Vasopressors

CNS — GCS

Renal — Creatinine (mg/dL) or UO

📚 Singer M, et al. Sepsis-3 Definitions. JAMA. 2016;315(8):801. | Marino's ICU Book 5th Ed, Ch.17 (2025)

qSOFA (Quick SOFA)

Bedside sepsis prognostic tool (NOT diagnostic). qSOFA ≥2 predicts ICU admission or death. Use NEWS/MEWS for screening (SSC 2026).

Respiratory Rate

Altered Mentation

Systolic Blood Pressure

📚 Singer M, et al. JAMA 2016. | SSC 2026 (Prescott et al., Crit Care Med 2026)

Glasgow Coma Scale (GCS)

Neurological assessment tool. Total 3–15. Mild TBI: 13–15; Moderate: 9–12; Severe: ≤8 (intubate). Teasdale & Jennett, Lancet 1974.

Eye Opening (E)

Verbal Response (V)

Motor Response (M)

📚 Teasdale G, Jennett B. Lancet 1974. | Marino's ICU Book 5th Ed, Ch.45 (2025)

RASS — Richmond Agitation-Sedation Scale

Assess sedation depth in ICU. Target RASS –1 to 0 for most ventilated patients. PADIS 2018 guidelines. Sessler et al., AJRCCM 2002.

Current Patient Behaviour

📚 Sessler CN, et al. AJRCCM 2002. | Devlin JW, et al. PADIS 2018 (Crit Care Med 2018)

CPOT — Critical Care Pain Observation Tool

Pain assessment in non-verbal/sedated ICU patients. Score 0–8. CPOT ≥3 = significant pain → increase analgesia. PADIS 2018. Gélinas et al., AJCC 2006.

Facial Expression

Body Movements

Muscle Tension (passive flexion/extension)

Compliance with Ventilator (ventilated) / Vocalisations (not ventilated)

📚 Gélinas C, et al. AJCC 2006. | Devlin JW, et al. PADIS 2018 (Crit Care Med 2018)

APACHE II Score

Acute Physiology And Chronic Health Evaluation II — the classic ICU severity-of-disease & mortality-prediction score (0–71), from the worst values in the first 24 h of ICU admission. Used for risk stratification, benchmarking/audit and research — not for individual treatment decisions. Knaus et al., Crit Care Med 1985.

Temperature (core, °C)

Mean arterial pressure (mmHg)

Heart rate (bpm)

Respiratory rate (/min)

Oxygenation (A–aDO₂ if FiO₂≥0.5; else PaO₂)

Arterial pH

Serum sodium (mEq/L)

Serum potassium (mEq/L)

Serum creatinine (mg/dL) — double if acute renal failure

Acute renal failure?

Haematocrit (%)

White cell count (×10³/µL)

Glasgow Coma Scale (3–15) points = 15 − GCS

Age (years)

Chronic health (severe organ insufficiency / immunocompromise)

📚 Knaus WA, Draper EA, Wagner DP, Zimmerman JE. APACHE II: a severity of disease classification system. Crit Care Med 1985;13:818–829. Mortality estimates are population-level and assume diagnosis weighting; use for stratification/audit, not individual prognosis.

CURB-65 (Pneumonia Severity)

Community-acquired pneumonia severity score. Guides admission decision. BTS Guidelines. Lim et al., Thorax 2003.

C — Confusion (new onset)

U — Urea >7 mmol/L (BUN >19 mg/dL)

R — Respiratory Rate ≥30/min

B — BP (SBP <90 or DBP ≤60 mmHg)

65 — Age ≥65 years

📚 Lim WS, et al. Thorax 2003;58(5):377. | Marino's ICU Book 5th Ed, Ch.29 (2025)

NEWS2 — National Early Warning Score 2

Early warning score for acute deterioration. SSC 2026 recommends NEWS2 over qSOFA for sepsis screening. RCP Guidelines 2017.

Respiratory Rate (/min)

SpO₂ — Scale 1 (no supplemental O₂)

On Supplemental O₂?

Systolic BP (mmHg)

Pulse Rate (/min)

Level of Consciousness (ACVPU)

Temperature (°C)

📚 Royal College of Physicians. NEWS2 (2017). | SSC 2026: Recommend NEWS/NEWS2 over qSOFA for sepsis screening.

Wells Score — DVT

Pre-test probability for deep vein thrombosis. Wells et al., Lancet 1997. Use with D-dimer to guide imaging decisions.

Active cancer (treatment within 6 months or palliative)

Paralysis, paresis, or recent plaster immobilisation of legs

Recently bedridden >3 days or major surgery within 12 weeks

Localised tenderness along deep venous system

Entire leg swollen

Calf swelling >3 cm compared to other leg

Pitting oedema (greater in symptomatic leg)

Collateral superficial veins (non-varicose)

Alternative diagnosis at least as likely as DVT

📚 Wells PS, et al. Lancet 1997;350(9094):1795. | Marino's ICU Book 5th Ed, Ch.5 (2025)

Wells Score — Pulmonary Embolism

Pre-test probability for pulmonary embolism. Use with D-dimer to decide CT-PA. Wells et al., Ann Intern Med 2001.

Clinical signs/symptoms of DVT (leg swelling, pain on deep vein palpation)

PE is #1 diagnosis OR equally likely

HR >100 bpm

Immobilisation ≥3 days OR surgery in past 4 weeks

Previous DVT or PE

Haemoptysis

Malignancy (treatment within 6 months or palliative)

📚 Wells PS, et al. Ann Intern Med 2001;135(2):98. | Marino's ICU Book 5th Ed, Ch.22 (2025)

HEART Score (ACS Risk)

History, ECG, Age, Risk factors, Troponin. Stratifies chest pain patients. HEART score ≥7: high risk (65% MACE). Backus et al., Heart 2010.

H — History

E — ECG

A — Age

R — Risk Factors (DM, HTN, hypercholesterolaemia, obesity BMI>30, smoking, family Hx)

T — Troponin (× upper limit of normal)

📚 Backus BE, et al. Heart 2010;96(19):1569. | ACC/AHA/ACEP ACS Guidelines 2025

DECAF Score (COPD Exacerbation)

Predicts in-hospital mortality in COPD exacerbation. DECAF ≥3 = high risk (29% mortality). Steer et al., Thorax 2012.

D — Dyspnoea (MRC Grade 5b = too breathless to leave house or breathless when dressing)

E — Eosinopenia (eosinophils <0.05×10⁹/L)

C — Consolidation on CXR

A — Acidaemia (pH <7.30)

F — Atrial Fibrillation (on admission ECG or known AF)

📚 Steer J, et al. Thorax 2012;67(11):970. | GOLD 2026 Report (goldcopd.org)

P/F Ratio (ARDS Severity)

PaO₂/FiO₂ ratio — determines ARDS severity. 2023 Global ARDS Definition. Matthay et al., AJRCCM 2024.

PaO₂ (mmHg) — from ABG

FiO₂ (0.21–1.0) — fraction of inspired oxygen

📚 ARDS Network. NEJM 2000. | Matthay MA, et al. AJRCCM 2024;209(4):374 (Global ARDS Definition 2023)

Driving Pressure (ΔP)

ΔP = Pplat − PEEP. Best predictor of ARDS mortality. Target <14–15 cmH₂O. Amato et al., NEJM 2015.

Plateau Pressure (Pplat, cmH₂O)

PEEP (cmH₂O)

📚 Amato MB, et al. Driving Pressure and Survival in ARDS. NEJM 2015;372(8):747. | ARDSNet Protocol (2000)

IBW & Tidal Volume Calculator

Predicted Body Weight (Devine formula) + lung-protective tidal volume (6–8 ml/kg PBW). ARDSNet 2000. Mandatory for ARDS ventilation.

Sex

Height (cm)

📚 Devine BJ. Drug Intelligence 1974. | ARDS Network. NEJM 2000;342:1301. | Marino's ICU Book 5th Ed, Ch.27 (2025)

GRACE Score (ACS Mortality)

Predicts 6-month post-discharge mortality in NSTEMI/UA. GRACE >140: high risk → early invasive strategy (<24h). Fox KAA, et al., BMJ 2006.

Age (years)

Heart Rate (bpm)

Systolic BP (mmHg)

Serum Creatinine (mg/dL)

Killip Class (Heart Failure)

Cardiac Arrest at Admission

Elevated Cardiac Enzymes/Troponin

ST-Segment Deviation

📚 Fox KAA, et al. BMJ 2006;333:1091. | ACC/AHA/ACEP ACS Guidelines 2025

NIHSS — NIH Stroke Scale (Simplified)

Quantifies stroke severity. NIHSS ≥4: significant deficit. >16: severe. Guides tPA eligibility. Brott T, et al., Stroke 1989.

1a. Level of Consciousness

1b. LOC Questions (month + age — 0,1,2 errors)

1c. LOC Commands (open/close eyes + grip/release)

2. Gaze (horizontal eye movement)

3. Visual Fields

4. Facial Palsy

5a. Motor — Left Arm (10 sec test)

5b. Motor — Right Arm

6a. Motor — Left Leg (5 sec test)

6b. Motor — Right Leg

8. Sensory

9. Language/Aphasia

10. Dysarthria

📚 Brott T, et al. Stroke 1989;20(7):864. | AHA/ASA Ischaemic Stroke Guidelines 2023

MELD Score (Liver Disease)

Model for End-Stage Liver Disease. Predicts 90-day mortality. Used for transplant prioritisation. MELD ≥18: consider transplant listing. Kamath et al., Hepatology 2001.

Bilirubin (mg/dL)

INR

Creatinine (mg/dL)

On Dialysis / CRRT (≥2×/week)?

📚 Kamath PS, et al. Hepatology 2001;33(2):464. | Marino's ICU Book 5th Ed, Ch.39 (2025)

Child-Pugh Score

Liver disease severity. Class A (5–6): good function. Class B (7–9): significant compromise. Class C (10–15): decompensated. Child & Turcotte, 1964.

Bilirubin (mg/dL)

Albumin (g/dL)

PT prolongation (seconds) / INR

Ascites

Hepatic Encephalopathy

📚 Child CG, Turcotte JG. Surgery 1964. | Pugh RNH, et al. Br J Surg 1973. | Marino's ICU Book 5th Ed, Ch.39 (2025)

eGFR — Cockcroft-Gault (CrCl)

Estimates creatinine clearance for drug dosing in AKI/CKD. Essential for adjusting aminoglycosides, vancomycin, renally-cleared drugs.

Age (years)

Weight (kg) — use IBW if obese

Serum Creatinine (mg/dL)

Sex

📚 Cockcroft DW, Gault MH. Nephron 1976;16(1):31. | Still preferred for drug dosing (KDIGO).

eGFR — CKD-EPI 2021 (race-free)

The current internationally recommended estimate of GFR (NKF–ASN Task Force 2021, KDIGO 2024). Race-free creatinine equation. Reports ml/min/1.73m² and CKD (G) stage.

Age (years)

Serum Creatinine (mg/dL)

Sex

📚 Inker LA et al. New Creatinine & Cystatin C Equations without Race. N Engl J Med 2021;385:1737. | NKF–ASN Task Force 2021 · KDIGO 2024 CKD Guideline. Cystatin C–based (CKD-EPI 2021 cr-cys) is preferred when confirmation needed.

Corrected Calcium (for albumin)

Total calcium must be corrected for albumin (each 1 g/dL fall in albumin lowers total Ca ~0.8 mg/dL). Ionised Ca is the gold standard when available.

Measured total Calcium (mg/dL)

Serum Albumin (g/dL)

📚 Payne RB et al. Br Med J 1973. Corrected Ca = measured + 0.8 × (4.0 − albumin). Verify with ionised Ca in critical illness.

Sodium Correction Rate (Hyponatraemia)

Adrogué–Madias: predicts the rise in serum Na per litre of infusate, and the volume/rate to safely raise Na. ⛔ Max 8–10 mEq/L per 24 h (ODS risk).

Current serum Na⁺ (mEq/L)

Weight (kg)

Sex / age (TBW factor)

Infusate

Target rise in 24 h (mEq/L)

📚 Adrogué HJ, Madias NE. N Engl J Med 2000;342:1581. | EJI Hyponatraemia Guideline 2014. ΔNa/L = (infusate Na − serum Na) ÷ (TBW + 1).

Free Water Deficit (Hypernatraemia)

Estimates the free-water deficit to correct hypernatraemia. ⛔ Lower Na no faster than 10 mEq/L per 24 h (cerebral oedema risk).

Current serum Na⁺ (mEq/L)

Weight (kg)

TBW factor

📚 Adrogué HJ, Madias NE. N Engl J Med 2000;342:1493. FWD = TBW × (Na/140 − 1). Add ongoing/insensible losses.

Potassium Deficit (estimate)

Approximate total-body K⁺ deficit. Rule of thumb: serum K⁺ falls ~0.3 mEq/L per ~100 mEq total deficit (steeper below 3.0). Replace Mg²⁺ too — hypomagnesaemia causes refractory hypokalaemia.

Current serum K⁺ (mEq/L)

Target K⁺ (mEq/L)

📚 Marino's ICU Book 5th Ed, Ch.35. Estimate only — recheck serum K⁺ after each 40 mEq. Peripheral max 10 mEq/h; central 10–20 mEq/h with ECG.

Ranson's Criteria (Pancreatitis)

Severity scoring for acute pancreatitis. Score ≥3: severe pancreatitis. At admission + at 48h criteria. Ranson JHC, et al., Surg Gynecol Obstet 1974.

At Admission

Age >55 years

WBC >16,000/mm³

Blood Glucose >200 mg/dL (11.1 mmol/L)

Serum LDH >350 IU/L

AST >250 IU/L

At 48 Hours

Haematocrit fall >10%

BUN rise >5 mg/dL

Serum Ca <8 mg/dL (2 mmol/L)

Arterial PO₂ <60 mmHg

Base deficit >4 mEq/L

Fluid sequestration >6L

📚 Ranson JHC, et al. Surg Gynecol Obstet 1974;139:69. | Marino's ICU Book 5th Ed, Ch.40 (2025)

ASA Physical Status Classification

American Society of Anesthesiologists classification. Assesses perioperative risk. ASA 2020 update. Essential for pre-operative assessment and consent.

Select Patient's Condition

Emergency Surgery? (Adds "E" suffix)

📚 ASA Physical Status Classification System. American Society of Anesthesiologists. Updated 2020. | Washington Manual of Critical Care, 4th Ed.