Presentation on theme: "Aim of the lecture To understand the basic principles of injury scoring systems. To review the principal of anatomical and physiological injury scoring."— Presentation transcript:
Aim of the lecture To understand the basic principles of injury scoring systems. To review the principal of anatomical and physiological injury scoring systems.
So we should answer the following questions Why should severity be assessed in trauma patients How can severity be assessed in trauma patients Where pre-hospital or hospital What is advantages and dis- advantages
Trauma has been termed the neglected disease of modern society, is among the leading causes of death in all age groups. Each year it is estimated that around 5.8 million people worldwide die as a result of trauma, with 90% of these deaths occurring in middle- and low- income countries.
Trauma is the third cause of death after cancer and cardiovascular diseases in the overall population. Hemorrhagic shock and traumatic brain injury (TBI) remain the leading causes of death accounting respectively for 30% and 50% in trauma patients arriving alive at the hospital (Harrois;etal 2013)
Severity assessment in trauma patients is mandatory. when? It started during initial phone call that alerts emergency services when a trauma occurred. On-call physician assesses severity based on witness provided information, to adapt emergency response.
Whenever information comes, it helps providing adequate therapeutics and orientating the patient to the appropriate hospital. Severity assessment is based upon pre-trauma medical conditions, mechanism of injury, anatomical lesions and their consequences on physiology.
Why should severity be assessed in trauma patients? System for field triage Assessment of injury severity is important clinically to Correct triage of patients to a trauma centre Selecting the adequate intensity of care and to prognosticating on short-/long-term patient outcome It is also important to the comparison of trauma centres
Three main groups of trauma scores Anatomical ( measure static component of injury). Physiological (measure acute dynamic component). Combined
Anatomical Traumatic patients may have normal physiology but may have anatomical lesions that require high level of care Injury Severity Score (ISS) Abbreviated Injury Scale (AIS) New Injury Severity Score (NISS) Anatomic Profile (AP)
Combined Trauma related Injury Severity Score - (TRISS). International Classification of Diseases Diseases-based ISS - (ICISS).
Abbreviated Injury Scale - (AIS) One of the hospital scores Was developed to rate and compare blunt injuries from road vehicle accidents. It has undergone several modifications since its introduction in 1971. currently updating AIS -2000. The AIS scores individual injuries and classifies them into one of six categories, each with an associated severity score ranges from1 (minor) to 6 (lethal). The severity scores were subjectively assigned by experts.
AIS – Limitations No comprehensive measure of severity Subjective Not predicting patient outcomes or mortality
Injury Severity Score (ISS) Hospital score The first significant scoring system to be based primarily on anatomic criteria was developed in 1974. Was created to define injury severity for comparative purposes. The strength of this system lies in its incorporation of anatomic indices and severity indices.
Injury Severity Score Six body regions Head. Face. Chest. Abdomen (including Pelvis). Extremities. External.
Example Injury Severity Score Square top 3 AISinjury descripition Region 9 0 16 25 50 304530304530 Cerebral contusion No injury Flail chest Liver contusion, spleen Fracture femur No injury ------------------------------- Head&neck Face Chest Abdomen Extremity External ISS
Injury Severity Score… 3 most severely injured body regions – score squared and added : ISS = a 2 +b 2 +c 2 Values ( 0 : 75 ) Patient with an ISS above 15 is considered as severe trauma patient. Any lesion with an AIS of 6 will automatically lead to increase ISS severity score.
Limitations of Injury Severity Score Error in AIS scoring increases ISS error Limits total number of injuries to 3 regions Description of patient injuries unknown Not a triage tool Does not take into account age or co-morbidities Not accurate for grading penetrating trauma
New Injury Severity Score - NISS Modified in 1997 from ISS It equals The sum of the squares of the AIS of each of the three most severe AIS injuries, regardless of the body region in which they occur.
New Injury Severity Score Predicts survival Easier to calculate than ISS Limitations of New Injury Severity Score No account for physiological variables
Anatomic Profile - (AP) Because of ISS limitations,a multidimensional characterization was sought that considers the number, location and severity of anatomic injuries and their influence on outcome. Includes all the serious and non-serious a injuries.
Anatomic Profile To describe apatients injuries: It uses Four categories (variables) A - Head and spinal cord B - Thorax and anterior neck C - All remaining serious injuries D - All non serious injuries. Serious (AIS = 3)
Anatomic Profile The scores are combined using an Euclidean Distance Model viz. the square root of the sum of the squares of the AIS scores of all serious injuries in each region. No injury = Zero allowing for decreasing influence of injuries as the number of injuries increases. Limitations Mathematical complexity
Trauma Score 1980 (TS) The widely used pre-hospital field triage tool,it has stood the test of time. a useful predictor of outcome for patients with blunt or penetrating injuries. Components Glasgow Coma Scale (GCS) Systolic Blood Pressure (SBP) Respiratory Rate (RR ) Respiratory expansion Capillary refill Revised due to difficult to assess in the field(particularly at night)
The Revised Trauma Score Two types of RTS: The coded form of the RTS is more frequently used for quality assurance and outcome prediction. The coded RTS is calculated as follows: RTSc = 0.7326 SBPc + 0.2908 RRc + 0.9368 GCSc Triage RTS: Determined by adding each of the coded values together.
Triage-Revised Trauma Score… Ranges 0:12 Score < 11 - transfer to trauma center (specificity 82%, sensitivity59%) Predicting mortality with RTS: RTS Mortality(%) 12 <1 10 12 6 37 2 70 0 >99 Champion HR, Sacco WJ, Copes WS, et al. A revision of the trauma score. J Trauma 1989;29:625, with permission
Limitations of Revised Trauma Score Not practical in field Underestimate the severity of head injury Problems: Intubated patients Influence of alcohol Drugs
The Glasgow Coma Scale - (GCS) Best Eye Response. (4) Best Verbal Response. (5) Best Motor Response. (6) 1.No eye opening. 2.Eye opening to pain. 3.Eye opening to verbal command. 4.Eyes open spontaneously. 1.No verbal response 2.Incomprehensib le sounds. 3.Inappropriate words. 4.Confused 5.Orientated 1.No motor response. 2.Extension to pain. 3.Flexion to pain. 4.Withdrawal from pain. 5.Localising pain. 6.Obeys Commands.
Trauma related injury severity score (TRISS) 1989 Combination scoring system Probability of trauma survival using anatomical and physiological scores. A logarithmic regression equation is used: Ps = 1/ (1+e^(-b)), The bs are regression coefficients. where b = bo + b1(RTS) + b2(ISS) + b3(AgeScore). RTS = (0.9368 x GCS) + (0.7326 x BPsys) +(0.2908 x RR) ISS calculated as above AgeScore = 0 if 55y. Coefficients (b0 : b3) depend on type of trauma
TRISS – Limitations Only moderately accurate for predicting survival Problems already noted with the ISS Similar to RTS, it cant include tubed patients as RR & verbal responses not obtainable Multiple injuries to same body region cannot measure
ASCOT (A Severity Characteristic of Trauma) TRISS has been the pre-eminent trauma outcome prediction model for the past 20 years. It is used to compare patient outcomes. Its greatest frailty is related to the Injury Severity Score (ISS). For that reason, ISS was replaced in the TRISS formulation by AP to create ASCOT.
When comparing ASCOT and TRISS, the ASCOT performs much better on outcome prediction than TRISS. However its complexity has deterred many from implementing it and TRISS still remains the mainstay of comparative analysis of trauma patients. A study reporting the replacement of ISS with NISS in TRISS would be a worthwhile contribution.
In an attempt to create a score that assesses severity in patients with medical prehospital care, Sartorius et al. identified four items that should be pooled:
Risk categories in new GAP (Rebecca etal; 2010) MGAP (Total points) GAP (Total points) % 23 : 29 18 : 22 3 : 17 19 :24 11 :18 3 :10 <5% 5:50% >50% Low Medium High
Kondo et al. Critical Care 2011, They studied 35,732 trauma patients in the Japan Trauma Data Bank from 2004 to 2009 in multicenters, as a prospective, observational study to assess whether the new Glasgow Coma Scale, Age, and Systolic Blood Pressure (GAP) scoring system, better predicts in- hospital mortality and can be applied more easily than previous trauma scores among trauma patients in the emergency department (ED). they concluded that: The GAP scoring system can predict in-hospital mortality more accurately than the previously developed trauma scoring systems.
Conclusion All the above-mentioned scores have been developed to predict mortality. Severity assessment of trauma patient helps guiding therapeutic, as well as orientating the patient in an adequate hospital. the GCS, RTS and GAP recommend these as the most reliable prehospital triage instruments. Instruments include ISS,NISS, TRISS and ASCOT systems for assessing outcomes and mortality.
Summary Why should severity be assessed in trauma patients? How can severity be assessed in trauma patients? Where pre-hospital or hospital? What is advantages and dis-advantages?
References http.//www.ATLS.org http.//www.ITLS.org http://www.jhsph.edu/Research/Centers/CIRP/ The Johns Hopkins Center for Injury Research & Policy http://www.trauma.org/A British web web-based trauma resource center http://www.trauma.org/scores/rtscalc.html/Revised