Trauma Scoring BC Trauma Registry October 24, 2011 Nasira Lakha Dori Williams

We’ll talk about…  Abbreviated Injury Scale (AIS)  Injury Severity Score (ISS)  Revised Trauma Score (RTS)  TRISS What do they mean? What do they mean? Why are they important? Why are they important? How does my documentation make an impact? How does my documentation make an impact? What is it all used for? What is it all used for?

Trauma Scoring  “Several trauma severity scales are used to quantify injury severity and describe patient severity casemix. Once injury is thus characterized, the results can be applied to triage, resourcing, research and quality of care assessment.”  1. Champion, HR: Trauma Scoring. Scandinavian Journal of Surgery 91: 2002.

 Different scoring systems exist to predict survival probability.  Although each scale can be used on its own as a predictive model, injury characterization involves complex descriptors which are both anatomical and physiological.  Therefore, there is a need for more than one single descriptor for injury characterization.

Abbreviated Injury Scale  The Abbreviated Injury Scale (AIS) is an anatomical global scoring system first introduced in 1971 by an Injury Scaling Committee of the Association for the Advancement of Automotive Medicine.  The AIS provides a standardized numerical method for ranking and describing the severity of injuries throughout the body.

history…  In mid-1960s, there was a need for a standardized system for categorizing injury type and severity at the same time as the first generation of multi-disciplinary motor vehicle crash investigation teams came to be.  Teams comprised of specialists in engineering, medicine, anatomy/physiology and crash investigation were responsible for collecting data for evaluation of vehicle design in relation to injury incidence and mechanism.  The goal was to obtain standardized data on frequency and severity of motor vehicle related injuries.  Under the sponsorship of the AAAM, American Medical Association and the Society of Automotive Engineers and about 35 other consultants, the first AIS was published.  The Injury Severity Score was then developed.  AIS was expanded to include injuries other than those that occur with vehicular trauma.  Several revisions followed – AIS 85, AIS 90, AIS 95, AIS 2005

AIS 9 Chapters Head Face Neck Thorax Abdomen & Pelvic Contents Spine Upper Extremities Lower Extremities External, Burns & Other Trauma

AIS Severity Code AIS Code Injury Description 1Minor 2Moderate 3Serious 4Severe 5Critical 6Maximal (currently untreatable)

Structure of Numerical Identifier: E.g. Tibial shaft fracture, open = = Body Region: Lower Extremity 5 = Type of Anatomic Structure: Skeletal 34 = Specific Anatomic Structure: Tibia 22 = Level of Injury: Shaft.3 = Severity Code: Serious

AIS injuries are categorized as follows within each chapter: Whole Area VesselsNerves Internal Organs Skeletal

Some chapters have more detail: Head– has two additional categories:  Length of Unconsciousness  Level of Unconsciousness Spine– is divided into 3 sections: Cervical, Thoracic and Lumbar and has a unique structure:  Cord Injury  Disc Injury  Ligament Injury  Nerve Root Injury  Whole Area Cervical Spine also contains: Brachial Plexus injury Cervical Spine also contains: Brachial Plexus injury Lumbar Spine also contains: Cauda Equina injury Lumbar Spine also contains: Cauda Equina injury

And… Abdomen & Pelvic Contents - does not contain skeletal injuries Upper & Lower Extremities - includes 2 additional categories:  muscles, tendons, ligaments  joints External, Burns, Other Trauma - has a unique structure:  Skin and Subcutaneous Tissue  Burns  Other Trauma

Injury descriptors affect the severity score of AIS: Loss of nerve function (total or partial) Basal skull fracture (CSF leak or not) Closed head injury/Blunt abdominal injury (leads to a non-specific code) Blood loss (pre-hospital and hospital) Vessel laceration (complete vs. incomplete transection) Pneumothorax (delayed appearance – complication?) Spinal cord injury (contusion vs. laceration and incomplete vs. complete) Skin injuries (length of laceration, size of avulsion or depth of penetrating injury) Pelvic Fracture (major vessel injury involvement?) Abdominal organ injuries (Organ Injury Scaling)

Primary Injury Types Blunt  Assault  Crush  Falls (3 categories)  Other Blunt  Vehicular Crash Penetrating  Cut  Firearm  Stab Thermal  Burn  Cold Exposure  Electrical Asphyxia  Drowning  Suffocation  Strangulation

Scenario  The patient was involved in a multi-vehicle car crash. Chest CT indicated multiple displaced and comminuted rib fractures bilaterally, a (L) pulmonary contusion, hemomediastinum, a fractured sternum and a (L) lung laceration. The patient was admitted to ICU for ventilatory support. There were also contusions to the arms, legs, chest and forehead.

INJURY SEVERITY SCORE  The Injury Severity Score was derived to summarize the severity of the condition of multiply injured patients.  Each injury is assigned an AIS score, allocated to one of six ISS body regions (Head or Neck, Face, Chest, Abdominal or Pelvic Contents, Extremities or Pelvic Girdle, External).  Only the highest AIS score in each ISS body region is used. 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 Sum of the squares of the highest AIS code in each of the three most severely injured ISS body regions

Example ISS Body Region Injury Description AIS Square Top Three Head & Neck Cerebral Contusion 39 Face No Injury - Chest Flail Chest 416 Abdomen Minor Contusion of Liver Complex Rupture Spleen Extremity Fracture femur 3 External No Injury - Injury Severity Score: 50

ISS ranges from 1 – 75  A score of 75 results in one of two ways, either with three AIS 5 injuries, or with at least one AIS 6 injury.  Any injury coded as AIS 6 is automatically assigned an ISS of 75.  It is not possible to calculate an ISS on a patient who has AIS 9 injury (the AIS code is unknown); hence, the need for detailed injury information.

Revised Trauma Score The Revised Trauma Score is a physiological scoring system. It is scored from the initial data obtained on the patient. The RTS correlates with the probability of survival. Components:  Glasgow Coma Score  Systolic Blood Pressure  Respiratory Rate

TRISS Methodology Trauma and Injury Severity Score (TRISS) was designed to calculate individual patient survival probabilities and to identify major trauma patients with unexpected outcomes. Risk adjusted mortality is calculated using TRISS methodology as a benchmarking tool to define performance against an historical international benchmark, the Major Trauma Outcome Study (MTOS). Components:  Revised Trauma Score (RTS)  Injury Severity Score (ISS)  Patient age  Mechanism of injury

This comprehensive dataset on the most severely injured patients in BC is utilized for:  Research activities  Injury prevention  Program reports  System planning  Performance improvement  Resource utilization  Patient care

QUESTIONS?