The Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring system is a severity-of-disease classification system. It leverages a collection of physiological measurements, age, and pre-existing health conditions to generate a score indicative of a patient’s overall health status upon admission to an intensive care unit. The higher the score, the greater the predicted risk of mortality. For instance, a patient with sepsis, renal failure, and advanced age would likely receive a substantially higher score than a younger patient admitted for observation after a minor injury.
The utility of such a scoring system lies in its ability to provide objective risk stratification. This supports clinical decision-making, enabling healthcare professionals to allocate resources effectively, compare outcomes across different patient populations, and assess the impact of interventions. Developed initially in the 1980s, the APACHE II system has been refined and adapted over time, becoming a standard tool for evaluating the severity of illness in critically ill patients. Its widespread adoption has significantly advanced the field of intensive care medicine by providing a standardized method for assessing and predicting patient outcomes.