Score is based on clinical characteristics of the patients. The higher the score out of a possible total of 10, the greater the chance of having acute appendicitis.
M: Migration of pain to right lower quadrant = 1 point
A: Anorexia = 1 point
N: Nausea and vomiting = 1 point
T: Tenderness in right lower quadrant = 2 points
R: Rebound tenderness = 1 point
E: Elevated temperature = 1 point
L: Leukocytosis = 2 points
S: Shift of WBC count to left = 1 point
The APACHE score is commonly used to establish illness severity in the ICU and predict the risk of death. There is a high risk of death if the score is 25 or above.
There are several other models that have been developed for use in the ICU, including APACHE III, Mortality in Emergency Department Sepsis score, Simplified Acute Physiology Score, Sepsis-related Organ Failure Assessment, and Mortality Probability Model II.   
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