Injury Scoring & Assigning an ISS The Trauma Audit & Research Network (TARN)
Injury Coding Ensuring coding uniformity Injury coding performed centrally at TARN Ensuring coding uniformity Coders check injury descriptions & imaging reports Abbreviated Injury Scale dictionary (AIS2005) used Every submission assigned an Injury Severity Score (ISS) >70,000 submissions per year coded
Abbreviated Injury Scale: AIS THE Internationally recognised system for injury scoring Produced by AAAM (Association for the Advancement of Automotive Medicine) in U.S.A Introduced in 1970, originally for Vehicle Crash investigators Latest version: AIS2005 >2000 injury descriptors Anatomically based system, ranking injuries according to severity on a 6 point ordinal scale
AIS: 6 point severity scale Grade Injury example 1 Minor Bruise to abdomen 2 Moderate Small Liver laceration 3 Serious Liver laceration with >1 litre of blood loss 4 Severe Ruptured liver 5 Critical Liver laceration involving hepatic vessels 6 Maximum Avulsed liver
It’s not a disability scale AIS Severity indicates The relative risk of “threat to life” in an average person who sustains the coded injury as his or her only injury It’s not a disability scale
AIS code structure: 7 digits Injury Numerical identifier Severity Score 853271.3 Comminuted Femoral Shaft # 853271 .3 140656.5 Large Subdural haemorrhage 140656 .5
Abbreviated Injury Scale: Sections Skin Degloving Penetrating Hypothermia Crush Asphyxia: Hanging/Strangulation Traumatic Amputation Drowning Nerve Frostbite Vessel Burns Joint Inhalation Skeletal Electrocution
AIS: Spinal Injuries Cervical Spine (C1-C7) Thoracic Spine (T1-T12) Lumbar spine (L1-L5) Severity can be affected by location of spinal injury
AIS: Confirmed injuries only Suspected injuries Possible injuries Probable injuries Ruled out injuries
AIS: Not Coded Infections Pneumonia Death Blindness Miscarriage Epilepsy following head injury Pulmonary embolism following skeletal injury Don’t affect Severity score
NFS: Not Further Specified This appears throughout the AIS dictionary & allows the coding of injuries when detailed information is lacking Example: Injury description = Liver laceration Coded as: 541820.2 (Liver laceration NFS)
AIS 6 not used just because a patient dies! AIS 6: Maximum score AIS 6 not used just because a patient dies! Has to be documented medical evidence of an AIS 6 injury
AIS 6: Maximum score Head or Neck Brain stem: laceration, crush, penetrating or transection C3 or higher complete cord transection or contusion Sigmoid or Transverse sinus or Internal carotid artery: Bilateral lacerations Thorax Heart: rupture, multiple lacerations or avulsion Total chest crush Aortic rupture + haemorrhage not confined to mediastinum Bilateral pulmonary artery or vein transection Severe inhalation Abdominal & Pelvic contents Liver avulsion External 2nd or 3rd degree burns > 90% Total Body Surface Massive Whole body Explosion type injury
AIS: Localisers 2 additional localiser codes, allow coding of: Localiser 1 Side or aspect of an injury e.g. Right, left, Upper, Temporal, Frontal Localiser 2 Actual Site of an injury e.g. 5th rib, 12th Thoracic vertebrae, 2nd toe Numerical identifier Severity Localiser 1 Localiser 2
Latest Version: AIS 2005 (Update 2008) AIS dictionary www.aaam.org Latest Version: AIS 2005 (Update 2008) $250 each
Injury Coding exercise
EXAMPLE SUBMISSION 1: INJURIES Page AIS code 853251.3 Spiral Fracture of left Shaft of Femur 147 Open Comminuted fracture to Tibial Shaft 149 854272.3 Vertical Shear fracture to left side of pelvis with blood loss >20% 159 856173.5 450203.3 5 ribs fractured on left 82 Subdural haematoma bilateral & 2cm thick on both sides 46 140655.5 Base of skull fracture 49 150200.3 Full thickness Rectal laceration 95 543624.3
Calculating the ISS Injury Severity Score
Calculating the ISS: Step 1 Determine the scores of the individual injuries using the Abbreviated Injury Scale
Identify the highest severity score in each body area Calculating the ISS: Step 2 Identify the highest severity score in each body area
Injury Severity Score: 6 body areas Head & Neck & Cervical spine Face Chest & Thoracic spine Abdomen & pelvic contents & Lumbar spine Extremities & bony pelvis External (incl. Skin injuries and Burns)
Head Thorax Abdomen Extremities Subdural haematoma bilateral & 2cm thick on both sides 140655.5 Base of skull fracture 150200.3 Thorax 5 ribs fractured on left 450203.3 Abdomen Full thickness Rectal laceration 543624.3 Extremities Spiral Fracture of left Shaft of Femur 853251.3 Vertical Shear fracture to left side of pelvis with blood loss >20% 856173.5 Open Comminuted fracture to Tibial Shaft 854272.3
Square the highest score in each body area Calculating the ISS: Step 3 Square the highest score in each body area
Head 5² =25 Thorax Abdomen Extremities 3² =9 3² =9 5² = 25 140655.5 Subdural haematoma bilateral & 2cm thick on both sides 140655.5 Base of skull fracture 150200.3 Thorax 5 ribs fractured on left 450203.3 Abdomen Full thickness Rectal laceration 543624.3 Extremities Spiral Fracture of left Shaft of Femur 853251.3 Vertical Shear fracture to left side of pelvis with blood loss >20% 856173.5 Open Comminuted fracture to Tibial Shaft 854272.3 5² =25 3² =9 3² =9 5² = 25
Calculating the ISS: Step 4 Code individual injuries Identify the highest score in each body area Square the highest score in each body area Add together the highest AIS2 from 3 different body areas
Head 5² =25 Thorax Abdomen Extremities 3² =9 3² =9 5² = 25 140655.5 Subdural haematoma bilateral & 2cm thick on both sides 140655.5 Base of skull fracture 150200.3 Thorax 5 ribs fractured on left 450203.3 Abdomen Full thickness Rectal laceration 543624.3 Extremities Spiral Fracture of left Shaft of Femur 853251.3 Vertical Shear fracture to left side of pelvis with blood loss >20% 856173.5 Open Comminuted fracture to Tibial Shaft 854272.3 5² =25 3² =9 3² =9 5² = 25
Injury Severity Score (ISS) = 59
Injury Severity Score (ISS) Body area Injury AIS code Head Closed vault fracture 150402.2 Thorax 5+6 ribs fractured on left 450202.2 2² = 4 2² = 4 This patient has 3 different injuries. 2 body regions injuries Highest scores are 9 (Thorax) and 4 (Head). ISS = 13 ISS = 8
Injury Severity Score (ISS) Ranges from 1 to 75 Maximum 75 achieved in 2 ways: Severity 5 in 3 different body areas 52 + 52 + 52 = 75 ISS convention: AIS = 6 in any body area, ISS = 75
Importance of Injury Detail Length, depth or Grade of lacerations (especially to internal organs) Depth, size and location of haemorrhages and contusions (especially in the brain) Open or Closed fractures Stability & site of Fractures (e.g. Comminuted/Displaced Shaft/Proximal/Distal fracture) Articular (joint) involvement (e.g. Intra-articular, extra-articular) Blood loss Vessel damage Location & number of rib fractures Compression or effacement of ventricles/brain stem cisterns Neurology associated with spinal cord injuries Instability, Blood loss or Vascular damage associated with Pelvic Fractures Cardiac arrest associated with asphyxia or drowning Ensure all injuries are documented Include imaging reports or Post Mortems for every submission.
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