AP BIOLOGY

Detailed explanation-1: -The ISS is an internationally recognised scoring system which correlates with mortality, morbidity and other measures of severity. The ISS is calculated as the sum of the squares of the highest AIS code in each of the three most severely injured ISS body regions.

Detailed explanation-2: -The ISS score takes values from 0 to 75. A score of 1 represents a minor injury and a score of 75 represents a fatal injury. By definition, any AIS body region score of 6 results automatically in an ISS of 75. An ISS score of 1 is possible if only one body region is injured.

Detailed explanation-3: -As a modification of ISS, NISS was proposed by Osler et al. in 1997. NISS was defined as the sum of squares of the three most severe injuries regardless of body region injured. By definition, NISS is at least equal to ISS when the most severe injuries are located in different ISS regions.

Detailed explanation-4: -Standardizes severity of traumatic injury based on worst injury of 6 body systems. Rate only the most severe injury from each body system. Used primarily in research settings, so calculation of the ISS should not delay initial management of patients with traumatic injuries.