Trauma Scoring Systems

IntroductionTrauma is the major cause of mortality & morbidity3 types of scoring system to asscess trauma patients:Anatomical: depend on accurate description or measurement of the injuryPhysiological: from observation & measurement of vital signs & blood indices (determine the degree of derangement)Combination

Anatomicalthe static component of injury: Penetrating injuries, limb paralysis, amputation proximal to the wrist, flail chest, pelvic fracture, and long bone fractures in two or more limb segmentsWhen used alone, their correlation with outcome is lower than combined with measures of physiologic states

AISAbbreviated Injury Scale (1971)Developed to rate & compare blunt injuries from road vehicle accidents for the American Medical Association Committee on Medical Aspects of Automotive Safety6 categoriesTo relate to risk of death in each body regionEach injury identified is recorded, and the highest scoring injury in each region noted(-): subjectively, inconsistency

ISSInjury Severity Score derived from Abbreviated Injury Scale (AIS)Introduced by Susan Baker & co-workers in 1984, primarily to describe injury severity in patients with polytrauma or multiple injury6 areas: head and neck, face, thorax, abdomen (including pelvic viscera), limbs (including the bony pelvis), and body surfacethe sum of squares of the highest AIS grades in each of the three most severely injured body regions.ISS = a2 + b2 + c2Major trauma ISS 16associated with mortality 10%(-): one-dimensional score of injury locations and severitiesA second injury in an anatomic regionll not scored may be greater severity than another injury in a different region which is scoredgreater influence on outcomethe first widely used scale to capture multiple injuries & it is still

APSAnatomic Profile ScoreIntroduced by Copes et al in 1990Because of ISS limitationsAPS = .3199(mA) + .4381(mB) + .1406(mC) +.7961(mD)Where:mA = quantification of head / spine injuriesmB= quantification of chest and neck injuriesmC= Quantification of all other serious injuriesmD= Quantification of all other non serious injuriesSerious injuries are those with AIS 3 to 6, while non-serious injuries are AIS 1 and 2. A region with no injury is scored 0A2 + B2 + C2 + D2complexity in calculation not widely used in injury severity scoring

PhysiologicalTrauma Score, RTS, Crams Scalemeasure the acute dynamic component

Trauma ScoreRR, respiratory expansion, SBP, CRT0-16 (worst-best prognosis)TS of 5, 10 and 15 probability of survival of 4%, 55% and 98%capillary refill and respiratory expansion were difficult to assess, especially at night

RTSRevised Trauma ScoreGCS, SBP, RR (0-12)Weight: GCS: 0.9368 / SBP: 0.7326 / RR: 0.2908

11: to trauma centerRTS of 10 or less is associated with up to 30% mortalityless than 6 (serious), from 6 to 7 (severe), from 8 to 10 (moderate) and from 11 to 12 (slight)Score

CRAMS Scale5 components: circulation, respiration, abdominal injury, and motor and speech responsesnormal (2), mildly abnormal (1), or severely abnormal (0)9 or 10minor trauma, e.g., patient discharged home8major trauma

Trauma Score and CRAMS have similar predictive values.Both have high false-negative triage ratesThe effectiveness of the Trauma Score is enhanced when it is used with additional information, e.g., on mechanism of injury, and extent and location of identifiable anatomic injuryAmerican College of Surgeons Committee on Trauma guidelines (Fig. 1) emphasize the importance of evaluating anatomic damage, even in the presence of normal physiology, and factors such as age (< 5 and > 55) and pre-existing disease that might lower the threshold at which patients should be triaged to a trauma center.

Fig. 1. Field triage decision scheme (from Resources for optimal care of the injured 1999, with permission from American College of Surgeons).

CombinedTRISS (TRauma score and Injury Severity Score): RTS, ISS, age & mechanism of injuryThe key mathematical element of TRISS is the logistic function[1] Ps = 1/(1 + eb)where Ps = estimate of a patients survival probability[2] b = bo + b1(RTS) + b2(ISS) + b3(AGE)AGE = 0 for age

ChallengesUnavailable dataDifficult to measure GCS in patients who are intubated or paralyzed, on alcohol or drugs2. Missing dataIt is notoriously difficult to get accurate and complete data in the early phases of care of the acutely injured individuals both in the prehospital and inhospital phases of care. It is unfortunate that the largest sources of missing data are always the most critical patients.3. Complex and military injuries

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