II. Background
- This page documents the APACHE 2 Score for historical purposes and for a general look overview of criteria
- APACHE 4 has replaced the APACHE 2 Score and is best performed via calculators
- APACHE 4 Calculator: Intensive Care network calculator
III. Indications
- Assess disease severity in Intensive Care unit patients (age >16 years old)
IV. Technique
- Calculate APACHE 2 score in the first 24 hours of ICU admission
V. Criteria: Rectal Temperature
- Score 4: Temperature > 41
- Score 3: Temperature 39 to 40.9
- Score 1: Temperature 38.5 to 38.9
- Score 0: Temperature 36 to 38.4
- Score 1: Temperature 34 to 35.9
- Score 2: Temperature 32 to 33.9
- Score 3: Temperature 30 to 31.9
- Score 4: Temperature <29.9
VI. Criteria: Mean arterial pressure (MAP)
- Score 4: Mean arterial pressure 160 mmHg or greater
- Score 3: Mean arterial pressure 130 to 159 mmHg
- Score 2: Mean arterial pressure 110 to 129 mmHg
- Score 0: Mean arterial pressure 70 to 109 mmHg
- Score 2: Mean arterial pressure 50 to 69 mmHg
- Score 4: Mean arterial pressure 49 mmHg or less
VII. Criteria: Heart Rate
- Score 4: Heart Rate 180 per minute or greater
- Score 3: Heart Rate 140 to 179 per minute
- Score 2: Heart Rate 110 to 139 per minute
- Score 0: Heart Rate 70 to 109 per minute
- Score 2: Heart Rate 55 to 69 per minute
- Score 3: Heart Rate 40 to 54 per minute
- Score 4: Heart Rate 39 per minute or less
VIII. Criteria: Respiratory Rate
- Score 4: Respiratory Rate 50 per minute or greater
- Score 3: Respiratory Rate 35 to 49 per minute
- Score 1: Respiratory Rate 25 to 34 per minute
- Score 0: Respiratory Rate 12 to 24 per minute
- Score 1: Respiratory Rate 10 to 11 per minute
- Score 2: Respiratory Rate 6 to 9 per minute
- Score 4: Respiratory Rate 5 per minute or less
IX. Criteria: A-a Gradient or PaO2
- Score 4: A-a Gradient 500 mmHg or greater (if on FIO2 >50%)
- Score 3: A-a Gradient 350 to 499 mmHg (if on FIO2 >50%)
- Score 2: A-a Gradient 200 to 349 mmHg (if on FIO2 >50%)
- Score 0: A-a Gradient <200 mmHg (if on FIO2 >50%) or PaO2 >70 mmHg (if on FIO2 <50%)
- Score 1: PaO2 61 to 70 mmHg (if on FIO2 <50%)
- Score 3: PaO2 55 to 60 mmHg (if on FIO2 <50%)
- Score 4: PaO2 55 mmHg or less (if on FIO2 <50%)
X. Criteria: Arterial pH or Bicarbonate (HCO3-)
- Score 4: Arterial pH 7.7 or Bicarbonate 52 or greater
- Score 3: Arterial pH 7.6 to 7.69 or Bicarbonate 41 to 51.9
- Score 1: Arterial pH 7.5 to 7.59 or Bicarbonate 32 to 40.9
- Score 0: Arterial pH 7.33 to 7.49 or Bicarbonate 23 to 31.9
- Score 2: Arterial pH 7.25 to 7.32 or Bicarbonate 18 to 22.9
- Score 3: Arterial pH 7.15 to 7.24 or Bicarbonate 15 to 17.9
- Score 4: Arterial pH <7.15 or Bicarbonate <15
XI. Criteria: Serum Sodium (Na+)
- Score 4: Serum Sodium 180 meq/L or greater
- Score 3: Serum Sodium 160 to 179 meq/L
- Score 2: Serum Sodium 155 to 159 meq/L
- Score 1: Serum Sodium 150 to 154 meq/L
- Score 0: Serum Sodium 30 to 149 meq/L
- Score 2: Serum Sodium 120 to 129 meq/L
- Score 3: Serum Sodium 111 to 119 meq/L
- Score 4: Serum Sodium 110 meq/L or less
XII. Criteria: Serum Potassium (K+)
- Score 4: Serum Potassium 7 meq/L or greater
- Score 3: Serum Potassium 6 to 6.9 meq/L
- Score 1: Serum Potassium 5.5 to 5.9 meq/L
- Score 0: Serum Potassium 3.5 to 5.4 meq/L
- Score 1: Serum Potassium 3 to 3.4 meq/L
- Score 2: Serum Potassium 2.5 to 2.9 meq/L
- Score 4: Serum Potassium <2.5 meq/L
XIII. Criteria: Serum Creatinine
- Score 8: Serum Creatinine 3.5 mg/dl or higher AND Acute Renal Failure
- Score 4: Serum Creatinine 3.5 mg/dl or higher
- Score 6: Serum Creatinine 2 to 3.4 mg/dl AND Acute Renal Failure
- Score 3: Serum Creatinine 2 to 3.4 mg/dl
- Score 4: Serum Creatinine 1.5 to 1.9 mg/dl AND Acute Renal Failure
- Score 2: Serum Creatinine 1.5 to 1.9 mg/dl
- Score 0: Serum Creatinine 0.6 to 1.4 mg/dl
- Score 2: Serum Creatinine <0.6 mg/dl
XIV. Criteria: Hematocrit
- Score 4: Hematocrit 60% or greater
- Score 2: Hematocrit 50 to 59.9%
- Score 1: Hematocrit 46 to 49.9%
- Score 0: Hematocrit 30 to 45.9%
- Score 2: Hematocrit 20 to 29.9%
- Score 4: Hematocrit <20%
XV. Criteria: White Blood Cell Count (WBC)
- Score 4: White Blood Cell Count 40 * 10^3/mm3 or higher
- Score 2: White Blood Cell Count 20 to 39.9 * 10^3/mm3
- Score 1: White Blood Cell Count 15 to 19.9 * 10^3/mm3
- Score 0: White Blood Cell Count 3 to 14.9 * 10^3/mm3
- Score 2: White Blood Cell Count 1 to 2.9 * 10^3/mm3
- Score 4: White Blood Cell Count <1 * 10^3/mm3
XVI. Criteria: Glasgow Coma Scale (GCS)
- Score = GCS - 15
XVII. Criteria: Age
- Score 6: Age 75 years or older
- Score 5: Age 65 to 74 years
- Score 3: Age 55 to 64 years
- Score 2: Age 45 to 54 years
- Score 0: Age 44 years or younger
XVIII. Criteria: Comorbidity
- Severe chronic health problems (one or more)
- Cirrhosis (confirmed by biopsy)
- Severe Congestive Heart Failure (NYHA Class 4)
- Severe COPD (hypercapnia, home oxygen or Pulmonary Hypertension >40 mmHg)
- End-stage renal disease on regularly scheduled Dialysis
- Immunocompromised
- Score 0: No severe comorbidities (from list above)
- Score 5: Medical (non-operative status) and one or more severe comorbidities
- Score 5: Post-operative status for emergent surgery and one or more severe comorbidities
- Score 2: Post-operative status for elective surgery and one or more severe comorbidities
XIX. Interpretation
- Total Score: 0 to 4
- Non-operative status: 4% mortality
- Post-operative status: 1% mortality
- Total Score: 5 to 9
- Non-operative status: 8% mortality
- Post-operative status: 3% mortality
- Total Score: 10-14
- Non-operative status: 15% mortality
- Post-operative status: 7% mortality
- Total Score: 15-19
- Non-operative status: 24% mortality
- Post-operative status: 12% mortality
- Total Score: 20-24
- Non-operative status: 40% mortality
- Post-operative status: 30% mortality
- Total Score: 25-29
- Non-operative status: 55% mortality
- Post-operative status: 35% mortality
- Total Score: 30-34
- Non-operative status: 73% mortality
- Post-operative status: 73% mortality
- Total Score: 35-100
- Non-operative status: 85% mortality
- Post-operative status: 88% mortality