APACHE II
Encyclopedia
APACHE II is a severity-of-disease classification system (Knaus et al., 1985), one of several ICU scoring systems
. It is applied within 24 hours of admission of a patient to an intensive care unit
(ICU): an integer score from 0 to 71 is computed based on several measurements; higher scores correspond to more severe disease and a higher risk of death.
This scoring system is used in many ways:
Even though newer scoring systems, such as SAPS II
, have replaced APACHE II in many places, APACHE II continues to be used extensively because so much documentation is based on it.
measurements, such as blood pressure, body temperature, heart rate, etc., during the first 24 hours after admission, information about previous health status, and some information obtained at admission (such as age). The calculation method is optimized for paper schemas, by using integer values and reducing the number of options so that data fit on a single-sheet paper form. The resulting point score should always be interpreted in relation to the illness of the patient.
The score is not recalculated during the stay—it is by definition an admission score. If a patient is discharged from the ICU and readmitted, a new APACHE II score is calculated.
The appendix of the document (see references) that originally described the APACHE II score, attempts to describe how to calculate a predicted death rate for a patient. In order to improve the accuracy of this calculation of predicted mortality, the principal diagnosis leading to ICU admission was added as a category weight: the predicted mortality is computed based on the patient's APACHE II score and their principal diagnosis at admission.
ICU scoring systems
-Adult scoring systems:* APACHE II was designed to provide a morbidity score for a patient. It is useful to decide what kind of treatment or medicine is given...
. It is applied within 24 hours of admission of a patient to an intensive care unit
Intensive Care Unit
thumb|220px|ICU roomAn intensive-care unit , critical-care unit , intensive-therapy unit/intensive-treatment unit is a specialized department in a hospital that provides intensive-care medicine...
(ICU): an integer score from 0 to 71 is computed based on several measurements; higher scores correspond to more severe disease and a higher risk of death.
Application
APACHE II was designed to measure the severity of disease for adult patients admitted to Intensive care units. The lower age bound is not specified in the original article, but a good limit is to use Apache II only for patients aged 15 or older.This scoring system is used in many ways:
- Some procedures and some medicine is only given to patients with a certain APACHE II score
- APACHE II score can be used to describe the morbidity of a patient when comparing the outcome with other patients.
- Predicted mortalities are averaged for groups of patients in order to specify the group's morbidity.
Even though newer scoring systems, such as SAPS II
SAPS II
SAPS II is a severity of disease classification system . Its name stands for "Simplified Acute Physiology Score", and is one of several ICU scoring systems.-Application:...
, have replaced APACHE II in many places, APACHE II continues to be used extensively because so much documentation is based on it.
Calculation
The point score is calculated from 12 routine physiologicalPhysiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...
measurements, such as blood pressure, body temperature, heart rate, etc., during the first 24 hours after admission, information about previous health status, and some information obtained at admission (such as age). The calculation method is optimized for paper schemas, by using integer values and reducing the number of options so that data fit on a single-sheet paper form. The resulting point score should always be interpreted in relation to the illness of the patient.
The score is not recalculated during the stay—it is by definition an admission score. If a patient is discharged from the ICU and readmitted, a new APACHE II score is calculated.
The appendix of the document (see references) that originally described the APACHE II score, attempts to describe how to calculate a predicted death rate for a patient. In order to improve the accuracy of this calculation of predicted mortality, the principal diagnosis leading to ICU admission was added as a category weight: the predicted mortality is computed based on the patient's APACHE II score and their principal diagnosis at admission.
APACHE III
A method to compute a refined score known as APACHE III was published in 1991. The score was validated on the dataset from 17,440 adult medical/surgical intensive care unit (ICU) admissions at 40 US hospitals. APACHE III scores range from 0 to 299 .See also
- ASA physical status classification system
- Glasgow Coma ScaleGlasgow Coma ScaleGlasgow Coma Scale or GCS is a neurological scale that aims to give a reliable, objective way of recording the conscious state of a person for initial as well as subsequent assessment...
(used by APACHE II)