The Trauma and Injury Severity Score (TRISS) revised

Early implementation of continuous renal replacement therapy optimizes casualty evacuation for combat-related acute kidney injury

BACKGROUND

The purpose of this report was to review the initial use and feasibility of continuous renal replacement therapy (CRRT) among combat casualties in a war zone. Although rapid evacuation to more advanced levels of care has emerged as the standard approach, life-threatening sequelae of acute kidney injury (AKI) can preclude safe patient evacuation. For the first time in US combat casualty care, a sustained, intensivist-led CRRT program was initiated during 2010 at an Air Force theater hospital.

METHODS

A prospective study of consecutive US service members (USSMs) who developed combat-related renal failure and underwent CRRT at the Craig Joint Theater Hospital was undertaken. Baseline patient characteristics, indications for CRRT, laboratory values, and outcomes were evaluated.

RESULTS

Nine USSMs were treated during 14-months. All were male, with a mean (SD) age of 28 (7) years and mean (SD) Injury Severity Score (ISS) of 34 (12). The dominant mechanism was blast injury (8 of 9), followed by gunshot wound (1 of 9). Most patients were Acute Kidney Injury Network (AKIN) 3 and all developed critical hyperkalemia (mean [SD], peak K⁺ 6.4 [0.4]). The peak plasma creatinine ranged from 1.4 mg/dL to 4.2 mg/dL (mean [SD], 3.3 [0.9] mg/dL). Patients had a mean (SD) of 17.6 [8.1] hours of CRRT before evacuation to higher echelons of care. All USSMs survived to achieve safe evacuation from the combat zone to the regional trauma center in Landstuhl, Germany (Landstuhl Regional Medical Center). Three patients died of multiorgan failure at Landstuhl Regional Medical Center. Six patients survived to undergo additional treatment in the United States.

CONCLUSION

Intensivist-led CRRT is an effective therapeutic adjunct in the treatment of combat-related AKI. Provision of this extracorporeal therapy provides physiologic stabilization of casualties who might otherwise succumb to the sequelae of combat-related renal failure. These findings suggest that a self-sustaining CRRT program can be successfully implemented in combat support hospitals.

Major trauma registry of Navarre (Spain): the accuracy of different survival prediction models

OBJECTIVE

To determine which factors predict death among trauma patients who are alive on arrival at hospital.

METHODS

Design prospective cohort study method. Data were collected on 378 trauma patients who were initially delivered by the emergency medical services of Navarre (Spain) with multiple injuries with a new injury severity score of 15 or more in 2011-2012. These data related to age, gender, presence of premorbid conditions, abbreviated injury score, injury severity score, new injury severity score (NISS), revised trauma score (RTS), and prehospital and hospital response times. Bivariate analysis was used to show the association between each variable and time until death. Mortality prediction was modeled using logistic regression analysis.

RESULTS

The variables related to the end result were the age of the patient, associated comorbidity, NISS, and hospital RTS. Two models were formulated: in one, the variables used were quantitative, while in the other model these variables were converted into dichotomous qualitative variables. The predictive capability of the two models was compared with the trauma and injury severity score using the area under the curve. The predictive capacities of the three models had areas under the curve of 0.93, 0.88, and 0.87. The response times of the Navarre emergency services system, measured as the sum of the time taken to reach the hospital (median time of 65 min), formulate computed tomography (46 min), and perform crucial surgery (115 min), when required, were not taken into account.

CONCLUSION

Age, premorbid conditions, hospital RTS, and NISS are significant predictors of death after trauma. The time intervals between the accident and arrival at the hospital, arrival at the hospital and the first computed tomography scan or the first crucial emergency intervention, do not appear to affect the risk of death.

Survival benefit of helicopter emergency medical services compared to ground emergency medical services in traumatized patients

INTRODUCTION

Physician-staffed helicopter emergency medical services (HEMS) are a well-established component of prehospital trauma care in Germany. Reduced rescue times and increased catchment area represent presumable specific advantages of HEMS. In contrast, the availability of HEMS is connected to a high financial burden and depends on the weather, day time and controlled visual flight rules. To date, clear evidence regarding the beneficial effects of HEMS in terms of improved clinical outcome has remained elusive.

METHODS

Traumatized patients (Injury Severity Score; ISS≥9) primarily treated by HEMS or ground emergency medical services (GEMS) between 2007 and 2009 were analyzed using the TraumaRegister DGU® of the German Society for Trauma Surgery. Only patients treated in German level I and II trauma centers with complete data referring to the transportation mode were included. Complications during hospital treatment included sepsis and organ failure according to the criteria of the American College of Chest Physicians/Society of Critical Care Medicine (ACCP/SCCM) consensus conference committee and the Sequential Organ Failure Assessment (SOFA) score.

RESULTS

A total of 13,220 patients with traumatic injuries were included in the present study. Of these, 62.3% (n=8,231) were transported by GEMS and 37.7% (n=4,989) by HEMS. Patients treated by HEMS were more seriously injured compared to GEMS (ISS 26.0 vs. 23.7, P<0.001) with more severe chest and abdominal injuries. The extent of medical treatment on-scene, which involved intubation, chest and treatment with vasopressors, was more extensive in HEMS (P<0.001) resulting in prolonged on-scene time (39.5 vs. 28.9 minutes, P<0.001). During their clinical course, HEMS patients more frequently developed multiple organ dysfunction syndrome (MODS) (HEMS: 33.4% vs. GEMS: 25.0%; P<0.001) and sepsis (HEMS: 8.9% vs. GEMS: 6.6%, P<0.001) resulting in an increased length of ICU treatment and in-hospital time (P<0.001). Multivariate logistic regression analysis found that after adjustment by 11 other variables the odds ratio for mortality in HEMS was 0.75 (95% CI: 0.636 to 862).

CONCLUSIONS

Although HEMS patients were more seriously injured and had a significantly higher incidence of MODS and sepsis, these patients demonstrated a survival benefit compared to GEMS.

Trauma survival prediction in Asian population: a modification of TRISS to improve accuracy

The probability of survival (PS) in blunt trauma as calculated by Trauma and Injury Severity Score (TRISS) has been an indispensable tool in trauma audit. The aim of this study is to explore the predictive performance of the latest updated TRISS model by investigating the Age variable recategorisations and application of local Injury Severity Score (ISS) and Revised Trauma Score (RTS) coefficients in a logistic model using a level I trauma centre database involving Asian population.

METHODS

Prospectively and consecutively collected 5684 trauma patients' data over a 10-year period at a regional level I trauma centre were reviewed. Four modified TRISS (mTRISS) models using Age coefficient from reclassifications of the Age variable according to their correlation with survival by logistic regression on the local dataset were acquired. RTS and ISS coefficients were derived from the local dataset and then applied to the mTRISS models. mTRISS models were compared with the existing Major Trauma Outcome Study (MTOS)-derived TRISS (eTRISS) model. Model 1=Age effect taken as linear; Model 2=Age classified into two groups (0-54, 55+); Model 3=Age classified into four groups (0-15, 16-54, 55-79, 80+) and Model 4=Age classified into two groups (0-69, 70+). Performance measures including sensitivity, specificity, accuracy and area under the Receiver Operating Characteristic (ROC) curve were used to assess the various models. The cross-validation procedure consisted of comparing the P(S) obtained from mTRISS Models 1 and 2 with the P(S) obtained from the MTOS derived from eTRISS.

RESULTS

A 5147 blunt trauma patients' dataset was reviewed. Model 1, where Age was taken as a scale variable, demonstrated a substantial improvement in the survival prediction with 91.6% accuracy in blunt injuries as compared with 89.2% in the MTOS-derived TRISS. The 95% CI for ROC derived from mTRISS Model 1 was (0.923, 0.940), when compared with the hypothesised ROC value 0.886 obtained from eTRISS, it clearly indicated a significant improvement in predicting survival at 5% level. Furthermore, ROCs have shown clearly the superiority of Model 1 over Model 2, and of Model 2 over MTOS-derived TRISS. The recategorisation of the Age variable (Models 3 and 4) also demonstrated improved performance, but their strength was not as intense as in Model 1. Overall, the results point to the adoption of Model 1 as the best model for PS. Cross-validation analysis has further assured the validity of these findings.

CONCLUSIONS

The present study has demonstrated that (1) having the Age variable being dichotomised (cut-off at 55 years) as in the eTRISS, but with the application of a local dataset-derived coefficients give better TRISS survival prediction in Asian blunt trauma patients; (2) improved performance are found with certain recategorisation of the Age variable and (3) the accuracy can further be enhanced if the Age effect is taken to be linear, with the application of local dataset-derived coefficients.

Injury profiles related to mortality in patients with a low Injury Severity Score: a case-mix issue?

BACKGROUND

Outcome prediction models are widely used to evaluate trauma care. External benchmarking provides individual institutions with a tool to compare survival with a reference dataset. However, these models do have limitations. In this study, the hypothesis was tested whether specific injuries are associated with increased mortality and whether differences in case-mix of these injuries influence outcome comparison.

METHODS

A retrospective study was conducted in a Dutch trauma region. Injury profiles, based on injuries most frequently endured by unexpected death, were determined. The association between these injury profiles and mortality was studied in patients with a low Injury Severity Score by logistic regression. The standardized survival of our population (Ws statistic) was compared with North-American and British reference databases, with and without patients suffering from previously defined injury profiles.

RESULTS

In total, 14,811 patients were included. Hip fractures, minor pelvic fractures, femur fractures, and minor thoracic injuries were significantly associated with mortality corrected for age, sex, and physiologic derangement in patients with a low injury severity. Odds ratios ranged from 2.42 to 2.92. The Ws statistic for comparison with North-American databases significantly improved after exclusion of patients with these injuries. The Ws statistic for comparison with a British reference database remained unchanged.

CONCLUSIONS

Hip fractures, minor pelvic fractures, femur fractures, and minor thoracic wall injuries are associated with increased mortality. Comparative outcome analysis of a population with a reference database that differs in case-mix with respect to these injuries should be interpreted cautiously.

LEVEL OF EVIDENCE

Prognostic study, level II.

The epidemiology of amputation injuries in the Austrian helicopter emergency medical service: a retrospective, nationwide cohort study

PURPOSE

Data on the epidemiological characteristics of traumatic amputations in prehospital emergency care, especially in the context of air rescue, are scarce. Therefore, we aimed to describe the epidemiology of total and subtotal amputation injuries encountered by the OEAMTC helicopter emergency medical service (HEMS) in Austria, based on an almost nationwide sample.

METHODS

We retrospectively reviewed all HEMS rescue missions flown for amputation injuries in 2009. Only primary missions were analyzed.

RESULTS

In total, 149 out of 16,100 (0.9 %) primary HEMS rescue missions were for patients suffering from amputation injuries. Among these, HEMS physicians diagnosed 63.3 % (n = 94) total and 36.9 % (n = 55) subtotal amputations, with both groups showing a predominance of male victims (male:female ratios were 8:1 and 6:1, respectively).The highest rate occurred among adults between 45 and 64 years of age (35.6 %, n = 53). The most common causes were working with a circular saw (28.9 %, n = 43) and processing wood (16.8 %, n = 25). The majority of the cases included digital amputation injuries (77.2 %, n = 115) that were mainly related to the index finger (36.2 %, n = 54). One hundred forty patients (94.0 %) showed a total GCS of more than 12. Amputations were most prevalent in rural areas (84.6 %, n = 126) and between Thursday and Saturday (55.0 %, n = 82). The replantation rate after primary air transport was low (28 %).

CONCLUSIONS

In the HEMS, amputation injuries are infrequent and mostly not life-threatening. However, HEMS crews need to maintain their focus on providing sufficient and fast primary care while facilitating rapid transport to a specialized hospital. The knowledge of the epidemiological characteristics of amputation injuries encountered in the HEMS gained in this study may be useful for educational and operational purposes.

Injury severity scoring systems: a review of application to practice

AIM

This study reviews the historical development of injury severity scoring systems and their application to clinical practice.

BACKGROUND

A variety of injury severity scoring systems have been developed and applied since more than four decades. It is increasingly important for nurses to be familiar with these scoring systems, their strengths and weaknesses, and their applications to nursing practice.

DESIGN

Systematic literature review.

METHODS

The injury severity scoring systems developed from the 1970s to 2011 were identified via electronic database searches, footnote chasing and contact with clinical experts. The most frequently used scoring systems in the literature were classified according to the criteria used in each scoring system.

CONCLUSIONS

All injury severity scoring systems are valuable but have certain problems. A universal scoring system applicable for various purposes appears difficult to achieve. However, the understanding and proper use of scoring systems will allow us to perform critical evaluations and continual refinement of trauma management.

RELEVANCE TO CLINICAL PRACTICE

As nurses and researchers, it is critical that we should know the application of these injury severity scoring systems to ensure their quality and appropriate utilization.