Measures for Describing Injuries Focus on Anatomical Injury ...

Measures for Describing Injuries: Focus on Anatomical Injury Severity Ronald Maio, D.O. University of Michigan Categories • Nature – Type of Injury • Mechanism – External Cause of Injury • Intent – Intentional – Unintentional • Severity – Extent of damage from the Injury Nature and Mechanism of Injury • Based on International Classification of Diseases version 10 (ICD-10) N code – Specifically describes the injury • Based on International Classification of Diseases version 10 (ICD-10) E code – Specifically describes how the injury occurred Example • 58 year old emergency medicine physician from USA visiting Karpacz skis into tree and ruptures spleen • N code: 865.13 – Laceration of spleen extending into parenchyma • E code: 917.0 – Striking against or struck accidentally by objects in sports without subsequent fall • Unintentional Scales for Categorizing Injury Severity • Physiological – Change over duration of injury treatment period • Revised trauma score (RTS) • GCS • Anatomical – Location, specific lesion and relative severity • Probability measures for mortality – Combination • TRISS Anatomic Injury Scales Abbreviated Injury Scale (AIS) Injury severity Score - based on AIS Organ Injury Scaling - AAST grade I-V Anatomic Profile - more complex than ISS Abbreviated Injury Scale(AIS) AIS is an anatomically based ranking of individual injuries according to severity History of the AIS • First utilized in 1969 – Based in part on Cornell Aeronautical Labs through ACIR program (1950s) and GM modified version of the ACIR scale • Developed in response to the needs of: – Individual researchers – MDAI teams (established by Dr. Haddon) through USDOT • Standardized system for categorizing injury type and severity Intent of the AIS Ranking System • Provide vehicle safety designers with: – a scale that identified injuries as a threat to life or that cause impairment – Energy of force dissipated in producing the injury Body Regions • 9 body regions – – – – – – – – – Head Face Neck Thorax Abdomen and pelvic contents Spine Upper extremity Lower extremity Unspecified (Skin, Burns, Other Trauma) Type of Anatomic Structure • • • • • • • Whole Area Vessels Nerves Organs (include muscles and ligaments) Skeletal/Joints Head - LOC Skin Specific Anatomical Structure or Nature of Injury • • • • Whole Area Head Spine Vessels, Nerves, Organs, SkeletalBones, Joints Level • Specific injuries are assigned consecutive two-digit numbers beginning with 02 • NFS = 00 or 99 • A ranking of individual injuries according to severity Code 1 2 Category minor moderate Definition of AIS 3 4 5 6 serious(non life-threatening) severe(life-threatening, survival probable) critical(survival uncertain) Maximum Severity Injuries(currently untreatable) Minor Injury Category 1 • Superficial abrasions, contusions and lacerations • Most 1rst degree burns Moderate Category 2 • Major abrasion, contusion. Deep and/or extensive laceration. • 2nd - 3rd degree burns (10-19% tbsa) Serious (Not Life-Threatening) Category 3 • Laceration involving major nerves and/or vessels • 2nd - 3rd degree burns (20-29% tbsa) Severe (Life-Threatening) Category 4 • Open chest wound, flail chest, pneumomediastinum • 2nd-3rd degree burns (30-39% tbsa) Critical (Survival Uncertain) Category 5 • Rupture, avulsion or extensive laceration of intra-abdominal vessels or organs, except kidney, spleen or ureter • 2nd-3rd degree burns (40 -89% tbsa) Maximum severity (Currently untreatable) Category 6 • Aortic laceration (major) with hemorrhage not confined to mediastinum • 2nd - 3rd degree burn > 89% or charring to head or trunk or incinertion Aspect • • • • • • • • • • 1=Right 2=Left 3=Bilat. 4=Central 5=Anterior 6=Posterior 7=Superior 8= Inferior 9=Unknown 0=Whole Injury Severity Score • Anatomical scoring system that provides an overall score for patients with multiple injuries. Purpose of ISS • To classify and rate the severity of injuries in trauma • Predict mortality ISS Background • Based on 2,128 MVC occupants, pedestrians, and other road users whose injuries resulted in hospitalization or death (DOA, DIE included) • 7 area Baltimore hospitals participated Calculation of ISS • Based on highest AIS score allocated to one of six different body regions • ISS = (highest body region score)2 + (2nd highest body region score*)2 + (3rd highest body region score*)2 * cannot score the same body region twice ISS Body Regions (not the same as AIS) • • • • • • Head and Neck Face Chest Abdomen or pelvic contents Extremity or pelvic girdle External ISS calculation example • • • • • • Maximum AIS = 3 for head and neck Maximum AIS = 2 for face Maximum AIS = 0 for chest Maximum AIS = 0 for abdomen Maximum AIS = 2 for extremity Maximum AIS = 1 for external ISS = (3)2 + (2)2 + (2)2 = 17 ISS = 75 • Results in one of two ways, either with three AIS 5 injuries, or with at least one AIS 6 injury. ISS = 75 • Results in one of two ways, either with three AIS 5 injuries, or with at least one AIS 6 injury.