When is the Acute Physiology and Chronic Health Evaluation (APACHE) II score used and how often?

From the Guidelines

The APACHE II score should be used within the first 24 hours of a patient's admission to an intensive care unit (ICU) to assess disease severity and predict mortality risk, as recommended by the 2024 clinical practice guideline update by the Infectious Diseases Society of America 1.

Key Points

• The APACHE II score is a widely validated instrument that evaluates the chronic health score and 12 physiologic measurements, but it is not specific for acute pancreatitis (AP) and is not designed for day-to-day evaluation in any patient 1.
• The score is typically calculated once during the initial period using the worst physiological values recorded during that time, but some clinicians may recalculate it if there is a significant change in the patient's condition or to track progress.
• The APACHE II score incorporates 12 physiological measurements, age, and chronic health status to generate a score ranging from 0 to 71, with higher scores indicating more severe disease and higher mortality risk.
• A study of 161 patients found that the APACHE-II score demonstrated the highest accuracy for the prediction of severe acute pancreatitis (SAP) among various scoring systems, with a significant cutoff value of ≥ 8 1.
• The APACHE II score helps clinicians make informed decisions about treatment intensity, resource allocation, and provides objective data for discussions with patients and families about prognosis.

Clinical Considerations

• The APACHE II score is not designed for repeated measurements, but it can be recalculated if there is a significant change in the patient's condition or to track progress.
• The score is widely used due to its relative simplicity and established validation across many clinical settings, despite the existence of newer versions (APACHE III and IV).
• The 2024 clinical practice guideline update by the Infectious Diseases Society of America suggests using the APACHE II score for risk stratification within 24 hours of hospitalization or ICU admission in adults with complicated intra-abdominal infection, with a conditional recommendation and low certainty of evidence 1.

From the Research

APACHE II Score Usage

• The APACHE II score is used to assess the severity of patients' diseases in general intensive care units (ICUs) 2.
• It is also used in neurologic ICUs to predict patient's condition and prognosis 2.
• The score is calculated within the first 24 hours of ICU admission 2, 3.
• APACHE II scores are associated with higher actual mortality, especially for patients with scores greater than 10 2.

Frequency of APACHE II Score Usage

• The APACHE II score is commonly used in ICUs to assess disease severity 2, 4.
• It is used in conjunction with other scoring systems, such as SAPS II and SOFA, to evaluate patient prognosis 4, 5, 6.
• The score is used to predict ICU admission and mortality in patients with COVID-19 3.
• APACHE II scores are calculated for all patients admitted to the ICU, regardless of their diagnosis or condition 2, 4, 3, 5, 6.

Comparison with Other Scoring Systems

• APACHE II has better calibration and discrimination power than SAPS II and SOFA in some studies 4, 5.
• SAPS II score was found to be an independent risk factor of patient death in patients with haematological malignancies 6.
• APACHE II, SAPS II, and SOFA scores are all used to evaluate patient prognosis, but their effectiveness may vary depending on the patient population and condition 4, 5, 6.