AIS versus ISS versus GCS-what’s going on here?

The development of reliable, rapid, and easy-to-use scoring systems for determination severity of injury has been a major focus of trauma care and resuscitation for the past few decades. Such scales, most especially the Glasgow Coma Score in traumatic brain injury, have dramatically enhanced the ability of emergency personnel, physicians, and nurses to communicate the status and severity of injury in shorthand form, both verbally and in records, so that the broader medical community can immediately understand the clinical scenario when interpreting them. Furthermore, utilization of scoring systems to prognosticate has also been attempted with some modicum of success, but the scoring systems when used in isolation or even in combination with one another do have limitations and should be used with this in mind. Commonly employed systems aimed at classifying the totality of injury burden either by organ system or the body as a whole include the Abbreviated Injury Score (AIS) and the Injury Severity Score (ISS). This chapter discusses these scales/scores, their origins, utility and limitations, and their correlation with outcome.