Anaesthesia / Critical Care Emergency Medicine Strong — Crit Care Med 1985

APACHE II Score

Acute Physiology and Chronic Health Evaluation II. 14-parameter score predicting ICU mortality from acute physiology (12 variables), age, and chronic health points. Range 0–71.

Rectal Temperature (°C)*

Mean Arterial Pressure (MAP, mmHg)*

MAP = (SBP + 2 × DBP) / 3

Heart Rate (bpm)*

Respiratory Rate (breaths/min)*

Use spontaneous rate. If ventilated, use set rate.

Oxygenation*

If FiO₂ ≥0.5 (50%): use A-a gradient. If FiO₂ <0.5 (<50%): use PaO₂ (mmHg)

Arterial pH*

Serum Sodium (mmol/L)*

Serum Potassium (mmol/L)*

Serum Creatinine (μmol/L)*

Score is DOUBLED if acute renal failure (ARF) is present. Select the row that matches creatinine AND ARF status.

Haematocrit (%)*

White Cell Count (× 10⁹/L)*

Glasgow Coma Scale (GCS)*

APACHE II contribution = 15 − GCS. Select the patient's current GCS total.

Age (years)*

Chronic Health Points*

Organ insufficiency = hepatic (cirrhosis / portal hypertension), cardiovascular (NYHA IV), respiratory (chronic hypoxia / hypercapnia / pulmonary hypertension), renal (on dialysis), or immunocompromised

References

Knaus WA et al. APACHE II: A severity of disease classification system. Crit Care Med. 1985;13(10):818–829.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Pathways

Decision support only — verify against MDCalc, NICE, or your local guideline before clinical use.

References

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