The Most Common Tools to Measure Trauma Severity: A review Study

 

ARTICLE INFO	ABSTRACT
REVIEW ARTICLE	Introduction: Due to the increasing mortality rate from trauma, determining the severity of injury has a very important role in the prognosis of the injured person. On the other hand, the quality of medical care provided to the casualties is evaluated using the Trauma Scoring System. Various scales were used to determine the trauma severity of injured. In this study, the most commonly used tools are investigated. Methods: This review was conducted by searching throughout the Persian data bases of Magiran, Barakat, SID and English databases of Scopus, Web of sciences, PubMed, and Google scholar. To conduct the search, the following keywords were used: "Severity of Trauma", "Trauma scoring", and "Trauma Scoring System" without considering any time intervals. Our early search resulted in 2125 articles. Finally, 17 articles were analyzed and different functions of traumatic assessment tools were compared and studied. Results: Traumatic assessment methods vary based on the anatomical and physiological parameters and composition of these two methods. In this study, the Abbreviated Injury Scale (AIS), Injury Severity Score (ISS), and New Injury Severity Score (NISS) were considered as anatomical parameters; Revised Trauma Score (RTS) as physiological parameters; Trauma Score Injury Severity Score (TRISS) and A Severity Characterization of Trauma (ASCOST) were mentioned as a hybrid ranking system. Conclusion: Application of accurate scientific evaluations in trauma severity assessment methods and application of each method in its appropriate position would result in appropriate improvements in the development of trauma care.  In addition, these systems can play an important role in providing care to patients with traumatic injuries in the present and future. Keywords: Trauma scoring system; Trauma; Severity of trauma Abbreviations: AIS (Abbreviated Injury Scale), ISS (Injury Severity Score),  NISS(New ISS), RTS (Revised Trauma Score), TRISS )Trauma Score Injury Severity Score )ASCOST A Severity Characterization of Trauma)
Article history: Received: 16 Nov. 2018 Revised: 20 May 2019 Accepted: 10 July 2019
*Corresponding author: Adel Eftekhari Address: Department of Health in Emergency and Disaster, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Email: eftekhari@gmail.com Tel: +98-35-31492226

 
Introduction

T

rauma is the first cause of mortality and one of the main causes of disability and disorder among active population in the developing countries (1). Any injury, lesion, shock, harm, or accident that happen to human body is considered as a trauma in the medical sciences, provided that it was entered from the outside and no internal factor caused the injury (2). Management of the traumatic injuries is a major issue in medical science. In the management of traumatic patients, two important challenges exist that include delivering the injured person to the closer and more appropriate traumatic center and estimating the severity of the trauma. Due to an increase in the mortality rate caused by trauma, determining the casualty's severity of injury has a very vital role for prognosis of the injured person. Furthermore, this kind of assessments can be applied to evaluate the quality of medical care provided for casualties (3). Evaluating the trauma scores are necessary to perform any research, accurate assessment of injuries, compilation of preventive programs, quality of care improvement, assessment of the trauma centers' results and triage activities, and a quantitative measurable scale (4).
The trauma scoring system has different functions; provides accurate, reliable and demonstrable description about the injuries, and predicts mortality in all circumstances (5). In fact, these systems provide databases that include injured and severity scores, which can assess the quality of care and management of trauma. Furthermore, it estimates the mortality rate, predicts the length of hospital admission, and provides a criterion to monitor trauma centers (3).
Since several years ago, various scales have been used to determine the severity of trauma in casualties; some countries are using these scales currently. These scales use anatomical and physiological criteria as well as combination of them to determine the trauma severity (6). Different studies have provided a review and research of various methods for assessing the severity of trauma and the advantages and disadvantages of the methods. In this study, we tried to explain the calculation method of each case, summarizing the advantages and disadvantages of each process (7-9).
In the present study, we evaluated the methods of measurement, and function of six most commonly used trauma scoring systems (10), including abbreviated injury scale (AIS), injury severity score (ISS), new ISS (NISS) of the anatomical parameters, revised trauma score (RTS) of physiological parameters, trauma score-injury severity score (TRISS), and a severity characterization of trauma (ASCOST), as hybrid ranking systems.
Materials and Methods
This review was conducted by searching the Persian databases including; Danesh Gostar Barakat system, Magiran, SID, and English databases including Scopus, Web of Sciences, PubMed, and the Google scholar using the following keywords: "severity of trauma", "trauma scoring", and "trauma scoring systems" with no time limitation.
Of the total studied databases, 2125 articles were obtained; 1129 Records remained after removing duplicates. Consequently, 1105 articles were excluded after the title and abstract, and 124 full-text articles were analyzed. Furthermore, 14 articles were selected and other articles were excluded due to lack of necessary criteria.  Inclusion criteria were studies that indicated one of the six trauma severity assessment methods considered in this study and stated the reason for choosing this method and its computational method. The types of articles (including research, systematic review, etc.) were also included in the study. The included studies' reference lists were investigated and three other articles were included. As a result, a total of 17 related articles were analyzed (Information extracted from each article includes article title, introduced tool, calculation method, application, strengths, weaknesses). The results are shown in Figure 1.

 

Records after removing duplicates (n = 1229)

Articles and other records screened (n =124)

Articles and records excluded based on title and abstract  (n = 1105)

Articles and other records assessed for eligibility (n = 17)

Articles and records excluded based on contents (n = 110)

Articles and records assessed for references and Additional records identified by other sources (n = 3)

Articles identified by database searching (n = 2125)

 
Figure 1. Searching and selecting articles
 

Results
Initially, each trauma scoring system was explained along with the measurement method; then, the methods were compared based on the functionality and non-functionality (Table 1).

Table 1. Comparison of the trauma scoring system according to studies

Row	Trauma scoring system	Function/non-function
1	Abbreviated Injury Scale (AIS)	The AIS is an appropriate method to determine the severity of injury to parts of the body, but in a simple description, it is not appropriate among patients with multiple injuries (12,13).
2	INJURY SEVERITY SCORE (ISS)	It is often calculated in the initial assessment and recovery in the emergency department. It is difficult to predict results for injured people with severe injury to one part of the body. Generally used to evaluate the epidemiology of trauma (14,15). Major limitations are decreasing the ability to classify the ISS in grades higher than 15 (ISS> 15) and higher ages (3).
3	Trauma Score-Injury Severity Score )TRISS(	Mortality prediction of traumatic brain injuries to evaluate the survival rate of injured patients with regard to their characteristics(13,18,20)
4	Revised Trauma Score (RTS)	It is more worthwhile to identify traumatic injuries (triage) and determine their need to use specific facilities
5	ASCOST (A Severity Characterization of Trauma)	An appropriate criterion to identify injuries is without problem.
6	NISS (NEW ISS)	It is an edited scoring system of ISS. It has more prediction of complications and mortality than ISS. It is more efficient in severe traumas (25, 26). The limitation includes the lack of discrimination among severity of injury in different areas of the body (3).

 

1. Abbreviated Injury Scale (AIS)
One of the first methods to measure the severity of trauma was developed by the Committee on Medical Traffic Disaster (USA) in 1971. Since 1985, its penetrating and non-penetrating wounds were determined separately. From 1971, it was revised in the AIS system six times in different years and the latest change was called AIS-6 (11).
In this method, the amount of injury is investigated in six important parts of the body (head and neck, face, chest, abdomen, limbs, and external surface of the body). The severity of injuries ranges from 1= no injury to 6= fatal injury. Scores one and two are considered as weak to moderate injuries and six is perceived as fatal injuries. The AIS scoring method shows that 1= minor, 2 = moderate, 3 = serious, 4=severe, 5 = critical, and 6 = fatal injury (11).
2. Injury Severity Score (ISS):
 Considering that AIS was used to measure the severity of injury in a body organ and was not used for patients with multiple trauma, Baker et al. (1974) invented the ISS system. This system indicates the severity of injury in patients with multiple trauma (9). The ISS is defined as the sum squares of the highest AIS scores in each of the three severely injured physical areas. In the case that there was more than one injury in a particular area of the body, the highest AIS score would be used.
ISS = a² + b² + c²
In order to calculate the ISS, the AIS score of each injured body organ should be determined.

Then, three injuries that get the highest AIS scores will be selected. Later, the ISS is calculated by making the sum scores squared (8).
ISS = a² + b² + c²
The minimum and maximum ISS rates were three and 75, respectively. It is worth mentioning that if the AIS score of an organ is six (Nonsurvivable), the ISS score will be 75 automatically. In addition, if each of the three scores equals six, the score is calculated as 75 automatically. Since the score of 6 (Nonsurvivable) indicates the importance of having more medical care in life-sustaining, this may mean stopping more care in the patient's preference for a 6 score in each category (10,11).
3. Trauma injury severity score (TRISS):
Trauma injury severity score is a hybrid indicator, in which the patient's age, mechanism of injury, the condition of the symptoms, and vital signs of casualties are considered along with ISS. In order to calculate TRISS, the following equation is used (16, 17).
TRISS = B0 + B1 (RTS) + B2(ISS) + B3(AGE)
In the above-mentioned equation, regression coefficients are calculated using the related coefficients for penetrating and non-penetrating trauma according to the following coefficients.

Table 2. Regression coefficients in TRISS equation

	B3	B2	B1	B0
Non-penetrating trauma	-1,9052	-0,0768	0,9544	-1,2470
Penetrating trauma	-2,6676	-0,1516	1,430	-0,6029

 

Age was considered as zero for patients less than 55 years and one for older patients (18, 19).
4. Revised Trauma Score (RTS):
According to three Glasgow Coma Scale

(GCS *), the systolic blood pressure and respiratory rate are calculated according to the following table.
RTS: GCS + SBP + RR
 

Table 3. Coded values of RTS calculation variables

Coded values	RR	SBP	GCS
4	10-29	>89	13-15
3	>29	76-89	9-12
2	6-9	50-75	6-8
1	1-5	1-49	4-5
0	0	0	3

 

* The GCS or Japan Coma Scale (JCS) is a neurological criterion used to determine the depth. In other words, it is used to measure the severity of consciousness decrease among people higher than five years (14, 21).
The GCS consists of three parts. The first part is related to opening of eyes with four scores, the second part is the verbal answer with five scores, and the third part is attributed to motor response with six scores (18).
5. A severity characterization of trauma (ASCOST):
In 1990, another scale called ASCOST was used for the first time. In this method, the anatomical description of the lesion is performed using
the four components A, B, C, and D of the Anatomic Profile (an anatomical method to determine the severity of the trauma). Component A includes all the dangerous injuries (with AIS of more than 2) to the areas of the head, brain, and the spinal cord; component B includes dangerous injuries to the chest and anterior part of the neck; component C includes all harmful injuries (except the follow-ups); and component D includes non-dangerous injuries with AIS of one or two.
In order to calculate the values of each four components, the second root of the AIS total squares is calculated for the injuries related to that organ. The patients 'survival possibility with very appropriate or inappropriate prognoses is already determined (22). This probability is calculated for other patients using this equation:
  References