Predicting early death in patients with traumatic bleeding: development and validation of prognostic model

Development and validation of risk prediction model for adverse outcomes in trauma patients

BACKGROUND

The prognosis of trauma patients is highly dependent on early medical diagnosis. By constructing a nomogram model, the risk of adverse outcomes can be displayed intuitively and individually, which has important clinical implications for medical diagnosis.

OBJECTIVE

To develop and evaluate models for predicting patients with adverse outcomes of trauma that can be used in different data availability settings in China.

METHODS

This was a retrospective prognostic study using data from 8 public tertiary hospitals in China from 2018. The data were randomly divided into a development set and a validation set. Simple, improved and extended models predicting adverse outcomes were developed, with adverse outcomes defined as in-hospital death or ICU transfer, and patient clinical characteristics, vital signs, diagnoses, and laboratory test values as predictors. The results of the models were presented in the form of nomograms, and performance was evaluated using area under the receiver operating characteristic curve (ROC-AUC), precision-recall (PR) curves (PR-AUC), Hosmer-Lemeshow goodness-of-fit test, calibration curve, and decision curve analysis (DCA).

RESULTS

Our final dataset consisted of 18,629 patients (40.2% female, mean age of 52.3), 1,089 (5.85%) of whom resulted in adverse outcomes. In the external validation set, three models achieved ROC-AUC of 0.872, 0.881, and 0.903, and a PR-AUC of 0.339, 0.337, and 0.403, respectively. In terms of the calibration curves and DCA, the models also performed well.

CONCLUSIONS

This prognostic study found that three prediction models and nomograms including the patient clinical characteristics, vital signs, diagnoses, and laboratory test values can support clinicians in more accurately identifying patients who are at risk of adverse outcomes in different settings based on data availability.

Burden of fever and hospital mortality in patients admitted to the intensive care unit with isolated traumatic brain injury-A retrospective cohort study using continuous temperature data

BACKGROUND

Fever has been shown to be associated with poor outcomes in patients with traumatic brain injury. Earlier studies have used peak daily temperature to derive the burden of fever. The association between hospital mortality and fever burden calculated as the area under the temperature-time curve for the entire duration of intensive care unit (ICU) stay has not been studied before.

OBJECTIVES

The objective of this study was to investigate the association between the burden of fever and hospital mortality in patients with isolated traumatic brain injury admitted to the ICU.

METHODS

We conducted this retrospective cohort study using an electronic database in a tertiary ICU in Sydney. We included all adult patients admitted to the ICU with isolated traumatic brain injury over 3 years from 1 July 2017 to 30 June 2020. We collected data on demographics, clinical characteristics, and interventions for all patients. We defined the burden of fever as an area under the temperature-time curve above 37 °C. The primary outcome was hospital mortality. We used multivariable logistic regression to determine the association between burden of fever and hospital mortality. We assessed the importance of the burden of fever in a predictive model using machine-learning methods (Bagging and Random Forest).

RESULTS

A total of 88 patients (76% males, mean age: 54 ± 23 years, mean Acute Physiology and Chronic Health Evaluation [APACHE] II score: 15 ± 7) were included in the study, and 18 (20.5%) of the 88 patients died in hospital. Compared to survivors, the nonsurvivors had lower mean Glasgow Coma Scale (GCS) score at the scene, higher mean APACHE II and III scores, and higher rates of intracranial pressure monitoring, surgery, mechanical ventilation, use of vasopressors, and cooling. On multivariable logistic regression, age (odds ratio: 1.05, 95% confidence interval: 1.02-1.09, p = 0.01) was found to be an independent predictor of hospital mortality. A higher GCS score at the scene (odds ratio: 0.81, 95% confidence interval: 0.66-0.98, p = 0.03) was associated with survival. The burden of fever was not associated with hospital mortality. The top three important variables in the predictive model were APACHE III, GCS score at scene, and age.

CONCLUSION

The burden of fever was not an independent predictor of hospital mortality. The results of this study need to be confirmed in a large multicenter study.

SPIN-PM: a consensus framework to evaluate the presence of spin in studies on prediction models

OBJECTIVES

To develop a framework to identify and evaluate spin practices and its facilitators in studies on clinical prediction model regardless of the modeling technique.

STUDY DESIGN AND SETTING

We followed a three-phase consensus process: (1) premeeting literature review to generate items to be included; (2) a series of structured meetings to provide comments discussed and exchanged viewpoints on items to be included with a panel of experienced researchers; and (3) postmeeting review on final list of items and examples to be included. Through this iterative consensus process, a framework was derived after all panel's researchers agreed.

RESULTS

This consensus process involved a panel of eight researchers and resulted in SPIN-Prediction Models which consists of two categories of spin (misleading interpretation and misleading transportability), and within these categories, two forms of spin (spin practices and facilitators of spin). We provide criteria and examples.

CONCLUSION

We proposed this guidance aiming to facilitate not only the accurate reporting but also an accurate interpretation and extrapolation of clinical prediction models which will likely improve the reporting quality of subsequent research, as well as reduce research waste.

Pre-hospital tranexamic acid administration in patients with a severe hemorrhage: an evaluation after the implementation of tranexamic acid administration in the Dutch pre-hospital protocol

PURPOSE

To evaluate the pre-hospital administration of tranexamic acid in ambulance-treated trauma patients with a severe hemorrhage after the implementation of tranexamic acid administration in the Dutch pre-hospital protocol.

METHODS

All patients with a severe hemorrhage who were treated and conveyed by EMS professionals between January 2015, and December 2017, to any trauma-receiving emergency department in the eight participating trauma regions in the Netherlands, were included. A severe hemorrhage was defined as extracranial injury with > 20% body volume blood loss, an extremity amputation above the wrist or ankle, or a grade ≥ 4 visceral organ injury. The main outcome was to determine the proportion of patients with a severe hemorrhage who received pre-hospital treatment with tranexamic acid. A Generalized Linear Model (GLM) was performed to investigate the relationship between pre-hospital tranexamic acid treatment and 24 h mortality.

RESULTS

A total of 477 patients had a severe hemorrhage, of whom 124 patients (26.0%) received tranexamic acid before arriving at the hospital. More than half (58.4%) of the untreated patients were suspected of a severe hemorrhage by EMS professionals. Patients treated with tranexamic acid had a significantly lower risk on 24 h mortality than untreated patients (OR 0.43 [95% CI 0.19-0.97]).

CONCLUSION

Approximately a quarter of the patients with a severe hemorrhage received tranexamic acid before arriving at the hospital, while a severe hemorrhage was suspected in more than half of the non-treated patients. Severely hemorrhaging patients treated with tranexamic acid before arrival at the hospital had a lower risk to die within 24 h after injury.

Road Accidents, Polytrauma Patients, and Their Economic Burden

Trauma is a problem of global public health with economic, social and political extensions. It is constantly growing due to road accidents. The cost of hospitalization and the loss of working hours for those who managed to reach the hospital are huge for the national economy of each country. The purpose of the present study is to record the polytrauma patients of road accidents and to search for their economic cost. A total of 68 injured people were the study sample during the period 2014-2017. The study was conducted in a University hospital in Athens (Greece). The mean age of the patients was 36.67 years. The mortality was 13.2% and the mean cost of every polytrauma patient was 14.272 Euros. Nearly half of them had an infection, which increased the cost. Accident prevention, proper and timely treatment of injuries, monitoring, recording and controlling infections and reducing the length of hospitalization are some of the ways to reduce the financial cost of a traumatized person.

Blood management practices during rapid transfer of urgent trauma patients pre- and post-implementation of ROTEM®-guided transfusion

Objective

The ‘Red Blanket’ protocol fast tracks trauma patients with severe blood loss to the designated trauma operating theatre directly from the hospital helipad or Emergency Department. This study aimed to assess the impact of patient blood management (PBM) strategies on severely injured trauma patients treated under the ‘Red Blanket’ protocol at a quaternary referral hospital.

Methods

This retrospective review was conducted on all urgent trauma cases that were treated under the ‘Red Blanket’ protocol in a ten-year period between January 2007 and December 2017. The use of blood products and patient outcomes was compared between the 3.5-year periods pre- and post-ROTEM® implementation on 30th June 2014 (Jan 2011-June 2014 versus July 2014-Dec 2017).

Results

During the study period, 120 trauma patients were treated under the ‘Red Blanket’ protocol at our institution. Intention to treat analysis showed a reduction in fresh frozen plasma usage following the introduction of ROTEM®-guided transfusion. Furthermore, subgroup analysis suggested reduced blood product usage in patients who survived.

Conclusions

Patient blood management is a coordinated package of systems and tools, including education, patient logistics, anaemia management, intraoperative cell salvage, rotational thromboelastometry and massive transfusion protocols that together conserve blood products and improve outcomes. The implementation of ROTEM®-guided transfusion demonstrated a reduction in fresh frozen plasma usage.

Predictive value of tachycardia for mortality in trauma-related haemorrhagic shock: a systematic review and meta-regression

OBJECTIVES

Heart rate (HR) is one of the physiological variables in the early assessment of trauma-related haemorrhagic shock, according to Advanced Trauma Life Support (ATLS). However, its efficiency as predictor of mortality is contradicted by several studies. Furthermore, the linear association between HR and the severity of shock and blood loss presented by ATLS is doubtful. This systematic review aims to update current knowledge on the role of HR in the initial haemodynamic assessment of patients who had a trauma.

DESIGN

This study is a systematic review and meta-regression that follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations.

DATA SOURCES

EMBASE, MEDLINE, CENTRAL and Web of Science databases were systematically searched through on 1 September 2020.

ELIGIBILITY CRITERIA

Papers providing early HR and mortality data on bleeding patients who had a trauma were included. Patient cohorts were considered haemorrhagic if the inclusion criteria of the studies contained transfusion and/or positive focused assessment with sonography for trauma and/or postinjury haemodynamical instability and/or abdominal gunshot injury. Studies on burns, traumatic spinal or brain injuries were excluded. Papers published before January 2010 were not considered.

DATA EXTRACTION AND SYNTHESIS

Data extraction and risk of bias were assessed by two independent investigators. The association between HR and mortality of patients who had a trauma was assessed using meta-regression analysis. As subgroup analysis, meta-regression was performed on patients who received blood products.

RESULTS

From a total of 2017 papers, 19 studies met our eligibility criteria. Our primary meta-regression did not find a significant relation (p=0.847) between HR and mortality in patients who had a trauma with haemorrhage. Our subgroup analysis included 10 studies, and it could not reveal a linear association between HR and mortality rate.

CONCLUSIONS

In accordance with the literature demonstrating the multiphasic response of HR to bleeding, our study presents the lack of linear association between postinjury HR and mortality. Modifying the pattern of HR derangements in the ATLS shock classification may result in a more precise teaching tool for young clinicians.

Interleukin-6 as a prognostic biomarker of clinical outcomes after traumatic brain injury: a systematic review

Traumatic brain injury (TBI) is a major cause of mortality and morbidity worldwide. There are currently no early biomarkers for prognosis in routine clinical use. Interleukin-6 (IL-6) is a potential biomarker in the context of the established role of neuroinflammation in TBI recovery. Therefore, a systematic review of the literature was performed to assess and summarise the evidence for IL-6 secretion representing a useful biomarker for clinical outcomes. A multi-database literature search between January 1946 and July 2021 was performed. Studies were included if they reported adult TBI patients with IL-6 concentration in serum, cerebrospinal fluid (CSF) and/or brain parenchyma analysed with respect to functional outcome and/or mortality. A synthesis without meta-analysis is reported. Fifteen studies were included, reporting 699 patients. Most patients were male (71.7%), and the pooled mean age was 40.8 years; 78.1% sustained severe TBI. Eleven studies reported IL-6 levels in serum, six in CSF and one in the parenchyma. Five studies on serum demonstrated higher IL-6 concentrations were associated with poorer outcomes, and five showed no signification association. In CSF studies, one found higher IL-6 levels were associated with poorer outcomes, one found them to predict better outcomes and three found no association. Greater parenchymal IL-6 was associated with better outcomes. Despite some inconsistency in findings, it appears that exaggerated IL-6 secretion predicts poor outcomes after TBI. Future efforts require standardisation of IL-6 measurement practices as well as assessment of the importance of IL-6 concentration dynamics with respect to clinical outcomes, ideally within large prospective studies. Prospero registration number: CRD42021271200

Pre-hospital administration of tranexamic acid in trauma patients: A systematic review and meta-analysis

Background

The Clinical Randomization of an Antifibrinolytic in Significant Hemorrhage-2 (CRASH-2) trial proved that tranexamic acid (TXA) is a time-dependent drug, having a better outcome if given within 1-hour of injury. In order to test this theory, studies have been conducted to examine the effect of TXA in the pre-hospital setting. We conducted a systematic search and meta-analysis to evaluate the role of TXA administration in the civilian pre-hospital setting on patient outcomes.

Methods

Embase, Medline, CINAHL and Cochrane were searched for randomized control trials (RCTs), retrospective, and prospective studies that examined the effect of TXA on patients in the pre-hospital setting versus a control group. Outcome measures were overall mortality rate and thromboembolic events. Two authors extracted the data independently. To appraise the included studies, we used the NIH quality assessment tool for cohort and cross-sectional studies. Results are presented as Risk Ratio (RR), a random-effect model was implemented, and the I2 test was used to assess heterogeneity.

Results

The search identified 1886 papers, but only five retrospective studies met the inclusion/exclusion criteria and were selected for further analysis. A meta-analysis confirmed that TXA reduced the overall mortality rate (pooled risk ratio of 0.74 (95% CI 0.45, 1.25)) and thromboembolic events (risk ratio of 0.71 (95% CI 0.35, 1.44)).

Conclusion

The pooled effects for both outcome measures favour the administration of TXA in the pre-hospital setting, although none of the findings reported a significant effect. Our study highlights the need for additional high-quality evidence to validate the significance of these findings.

Level of evidence

Level III, therapeutic study.

Efficacy and safety of the second in-hospital dose of tranexamic acid after receiving the prehospital dose: double-blind randomized controlled clinical trial in a level 1 trauma center

Background

Prehospital administration of tranexamic acid (TXA) to injured patients is increasing worldwide. However, optimal TXA dose and need of a second infusion on hospital arrival remain undetermined. We investigated the efficacy and safety of the second in-hospital dose of TXA in injured patients receiving 1 g of TXA in the prehospital setting. We hypothesized that a second in-hospital dose of TXA improves survival of trauma patients.

Methods

A prospective, double-blind, placebo-controlled randomized, clinical trial included adult trauma patients receiving 1 g of TXA in the prehospital settings. Patients were then blindly randomized to Group I (second 1-g TXA) and Group II (placebo) on hospital arrival. The primary outcome was 24-h (early) and 28-day (late) mortality. Secondary outcomes were thromboembolic events, blood transfusions, hospital length of stay (HLOS) and organs failure (MOF).

Results

A total of 220 patients were enrolled, 110 in each group. The TXA and placebo groups had a similar early [OR 1.000 (0.062–16.192); p = 0.47] and late mortality [OR 0.476 (95% CI 0.157–1.442), p = 0.18].The cause of death (n = 15) was traumatic brain injury (TBI) in 12 patients and MOF in 3 patients. The need for blood transfusions in the first 24 h, number of transfused blood units, HLOS, thromboembolic events and multiorgan failure were comparable in the TXA and placebo groups. In seriously injured patients (injury severity score > 24), the MTP activation was higher in the placebo group (31.3% vs 11.10%, p = 0.13), whereas pulmonary embolism (6.9% vs 2.9%, p = 0.44) and late mortality (27.6% vs 14.3%, p = 0.17) were higher in the TXA group but did not reach statistical significance.

Conclusion

The second TXA dose did not change the mortality rate, need for blood transfusion, thromboembolic complications, organ failure and HLOS compared to a single prehospital dose and thus its routine administration should be revisited in larger and multicenter studies.

Trial registration

ClinicalTrials.gov Identifier: NCT03846973.

The Impact of Age on Predictive Performance of National Early Warning Score at Arrival to Emergency Departments: Development and External Validation

STUDY OBJECTIVE

To investigate how age affects the predictive performance of the National Early Warning Score (NEWS) at arrival to the emergency department (ED) regarding inhospital mortality and intensive care admission.

METHODS

International multicenter retrospective cohorts from 2 Danish and 3 Dutch ED. Development cohort: 14,809 Danish patients aged ≥18 years with at least systolic blood pressure or pulse measured from the Danish Multicenter Cohort. External validation cohort: 50,448 Dutch patients aged ≥18 years with all vital signs measured from the Netherlands Emergency Department Evaluation Database (NEED). Multivariable logistic regression was used for model building. Performance was evaluated overall and within age categories: 18 to 64 years, 65 to 80 years, and more than 80 years.

RESULTS

In the Danish Multicenter Cohort, a total of 2.5% died inhospital, and 2.8% were admitted to the ICU, compared with 2.8% and 1.6%, respectively, in the NEED. Age did not add information for the prediction of intensive care admission but was the strongest predictor for inhospital mortality. For NEWS alone, severe underestimation of risk was observed for persons above 80 while overall Area Under Receiver Operating Characteristic (AUROC) was 0.82 (confidence interval [CI] 0.80 to 0.84) in the Danish Multicenter Cohort versus 0.75 (CI 0.75 to 0.77) in the NEED. When combining NEWS with age, underestimation of risks was eliminated for persons above 80, and overall AUROC increased significantly to 0.86 (CI 0.85 to 0.88) in the Danish Multicenter Cohort versus 0.82 (CI 0.81 to 0.83) in the NEED.

CONCLUSION

Combining NEWS with age improved the prediction performance regarding inhospital mortality, mostly for persons aged above 80, and can potentially improve decision policies at arrival to EDs.

Why did European Radiology reject my radiomic biomarker paper? How to correctly evaluate imaging biomarkers in a clinical setting

This review explains in simple terms, accessible to the non-statistician, general principles regarding the correct research methods to develop and then evaluate imaging biomarkers in a clinical setting, including radiomic biomarkers. The distinction between diagnostic and prognostic biomarkers is made and emphasis placed on the need to assess clinical utility within the context of a multivariable model. Such models should not be restricted to imaging biomarkers and must include relevant disease and patient characteristics likely to be clinically useful. Biomarker utility is based on whether its addition to the basic clinical model improves diagnosis or prediction. Approaches to both model development and evaluation are explained and the need for adequate amounts of representative data stressed so as to avoid underpowering and overfitting. Advice is provided regarding how to report the research correctly. KEY POINTS: • Imaging biomarker research is common but methodological errors are encountered frequently that may mean the research is not clinically useful. • The clinical utility of imaging biomarkers is best assessed by their additive effect on multivariable models based on clinical factors known to be important. • The data used to develop such models should be sufficient for the number of variables investigated and the model should be evaluated, preferably using data unrelated to development.

Associations of On-arrival Vital Signs with 24-hour In-hospital Mortality in Adult Trauma Patients Admitted to Four Public University Hospitals in Urban India: A Prospective Multi-Centre Cohort Study

INTRODUCTION

In India, more than a million people die annually due to injuries. Identifying the patients at risk of early mortality (within 24 hour of hospital arrival) is essential for triage. A bilateral Government Australia-India Trauma System Collaboration generated a trauma registry in the context of India, which yielded a cohort of trauma patients for systematic observation and interventions. The aim of this study was to determine the independent association of on-arrival vital signs and Glasgow Coma Score (GCS) with 24-hour mortality among adult trauma patients admitted at four university public hospitals in urban India.

METHODS

We performed an analysis of a prospective multicentre observational study of trauma patients across four urban public university hospitals in India, between April 2016 and February 2018. The primary outcome was 24-hour in-hospital mortality. We used logistic regression to determine mutually independent associations of the vital signs and GCS with 24-hour mortality.

RESULTS

A total of 7497 adult patients (18 years and above) were included. The 24-hour mortality was 1.9%. In univariable logistic regression, Glasgow Coma Score (GCS) and the vital signs systolic blood pressure (SBP), heart rate (HR), respiratory rate (RR) and peripheral capillary oxygen saturation (SpO2) had statistically significant associations with 24-hour mortality. These relationships held in multivariable analysis with hypotension (SBP<90mm Hg), tachycardia (HR>100bpm) and bradycardia (HR<60bpm), hypoxia (SpO2<90%), Tachypnoea (RR>20brpm) and severe (3-8) and moderate (9-12) GCS having strong association with 24-hour mortality. Notably, the patients with missing values for SBP, HR and RR also demonstrated higher odds of 24-hour mortality. The Injury Severity Scores (ISS) did not corelate with 24-hour mortality.

CONCLUSION

The routinely measured GCS and vital signs including SBP, HR, SpO2 and RR are independently associated with 24-hour in-hospital mortality in the context of university hospitals of urban India. These easily measured parameters in the emergency setting may help improve decision-making and guide further management in the trauma victims. A poor short-term prognosis was also observed in patients in whom these physiological variables were not recorded.

Protocol for a multicentre prehospital randomised controlled trial investigating tranexamic acid in severe trauma: the PATCH-Trauma trial

INTRODUCTION

Haemorrhage causes most preventable prehospital trauma deaths and about a third of in-hospital trauma deaths. Tranexamic acid (TXA), administered soon after hospital arrival in certain trauma systems, is an effective therapy in preventing or managing acute traumatic coagulopathy. However, delayed administration of TXA appears to be ineffective or harmful. The effectiveness of prehospital TXA, incidence of thrombotic complications, benefit versus risk in advanced trauma systems and the mechanism of benefit remain uncertain.

METHODS AND ANALYSIS

The Pre-hospital Anti-fibrinolytics for Traumatic Coagulopathy and Haemorrhage (The PATCH-Trauma study) is comparing TXA, initiated prehospital and continued in hospital over 8 hours, with placebo in patients with severe trauma at risk of acute traumatic coagulopathy. We present the trial protocol and an overview of the statistical analysis plan. There will be 1316 patients recruited by prehospital clinicians in Australia, New Zealand and Germany. The primary outcome will be the eight-level Glasgow Outcome Scale Extended (GOSE) at 6 months after injury, dichotomised to favourable (GOSE 5-8) and unfavourable (GOSE 1-4) outcomes, analysed using an intention-to-treat (ITT) approach. Secondary outcomes will include mortality at hospital discharge and at 6 months, blood product usage, quality of life and the incidence of predefined adverse events.

ETHICS AND DISSEMINATION

The study was approved by The Alfred Hospital Research and Ethics Committee in Victoria and also approved in New South Wales, Queensland, South Australia, Tasmania and the Northern Territory. In New Zealand, Northern A Health and Disability Ethics Committee provided approval. In Germany, Witten/Herdecke University has provided ethics approval. The PATCH-Trauma study aims to provide definitive evidence of the effectiveness of prehospital TXA, when used in conjunction with current advanced trauma care, in improving outcomes after severe injury.

TRIAL REGISTRATION NUMBER

NCT02187120.

The Traumatic Brain Injury Model Systems National Database: A Review of Published Research

The Traumatic Brain Injury Model Systems (TBIMS) is the largest longitudinal TBI data set in the world. Our study reviews the works using TBIMS data for analysis in the last 5 years. A search (2015–2020) was conducted across PubMed, EMBASE, and Google Scholar for studies that used the National Institute on Disability, Independent Living and Rehabilitation Research NIDILRR/VA-TBIMS data. Search terms were as follows: [“TBIMS” national database] within PubMed and Google Scholar, and [“TBIMS” AND national AND database] on EMBASE. Data sources, study foci (in terms of data processing and outcomes), study outcomes, and follow-up information usage were collected to categorize the studies included in this review. Variable usage in terms of TBIMS' form-based variable groups and limitations from each study were also noted. Assessment was made on how TBIMS' objectives were met by the studies. Of the 74 articles reviewed, 23 used TBIMS along with other data sets. Fifty-four studies focused on specific outcome measures only, 6 assessed data aspects as a major focus, and 13 explored both. Sample sizes of the included studies ranged from 11 to 15,835. Forty-two of the 60 longitudinal studies assessed follow-up from 1 to 5 years, and 15 studies used 10 to 25 years of the same. Prominent variable groups as outcome measures were “Employment,” “FIM,” “DRS,” “PART-O,” “Satisfaction with Life,” “PHQ-9,” and “GOS-E.” Limited numbers of studies were published regarding tobacco consumption, the Brief Test of Adult Cognition by Telephone (BTACT), the Supervision Rating Scale (SRS), general health, and comorbidities as variables of interest. Generalizability was the most significant limitation mentioned by the studies. The TBIMS is a rich resource for large-sample longitudinal analyses of various TBI outcomes. Future efforts should focus on under-utilized variables and improving generalizability by validation of results across large-scale TBI data sets to better understand the heterogeneity of TBI.

Efficacy and Safety of Tranexamic Acid in Emergency Trauma: A Systematic Review and Meta-Analysis

In trauma patients, bleeding can lead to coagulopathy, hemorrhagic shock, and multiorgan failure, and therefore is of fundamental significance in regard to early morbidity. We conducted a meta-analysis to evaluate the efficacy and safety of tranexamic acid (TXA) in civil and military settings and its impact on in-hospital mortality (survival to hospital discharge or 30-day survival), intensive care unit and hospital length of stay, incidence of adverse events (myocardial infarct and neurological complications), and volume of blood product transfusion. The systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic review of the literature using PubMed, Scopus, EMBASE, Web of Science, and the Cochrane Central Register and Controlled Trials (CENTRAL) database was conducted from inception to 10 January 2021. In-hospital mortality was reported in 14 studies and was 15.5% for the TXA group as compared with 16.4% for the non-TXA group (OR = 0.81, 95% CI 0.62-1.06, I2 = 83%, p = 0.12). In a civilian TXA application, in-hospital mortality in the TXA and non-TXA groups amounted to 15.0% and 17.1%, respectively (OR = 0.69, 95% CI 0.51-0.93, p = 0.02, I2 = 78%). A subgroup analysis of the randomized control trial (RCT) studies showed a statistically significant reduction in in-hospital mortality in the TXA group (14.3%) as compared with the non-TXA group (15.7%, OR = 0.89, 95% CI 0.83-0.96, p = 0.003, I2 = 0%). To summarize, TXA used in civilian application reduces in-hospital mortality. Application of TXA is beneficial for severely injured patients who undergoing shock and require massive blood transfusions. Patients who undergo treatment with TXA should be monitored for clinical signs of thromboembolism, since TXA is a standalone risk factor of a thromboembolic event and the D-dimers in traumatic patients are almost always elevated.

Heart rate variability and pulmonary dysfunction in rats subjected to hemorrhagic shock

BACKGROUND

The activity of autonomic nervous system and its association with organ damage have not been entirely elucidated in hemorrhagic shock. The aim of this study was to investigate heart rate variability (HRV) and pulmonary gas exchange in hemorrhagic shock during unilateral subdiaphragmatic vagotomy.

METHODS

Male Sprague Dawley rats were randomly assigned into groups of Sham, vagotomized (Vag), hemorrhagic shock (HS) and Vag + HS. HS was induced in conscious animals by blood withdrawal until reaching to mean arterial blood pressure (MAP) of 40 ± 5 mmHg. Then, it was allowed to MAP returning toward the basal values. MAP and heart rate (HR) were recorded throughout the experiments, HRV components of low (LF, sympathetic index), high (LH, parasympathetic index), and very low (VLF, injury index) frequencies and the LF/HF ratio calculated, and the lung histological and blood gas parameters assessed.

RESULTS

In the initial phases of HS, the increase in HR with no change in MAP were observed in both HS and Vag + HS groups, while LF increased only in the HS group. In the second phase, HR and MAP decreased sharply in the HS group, whereas, only MAP decreased in the Vag + HS group. Meanwhile, LF and HF increased relative to their baselines in the HS and Vag + HS groups, even though the values were much pronounced in the HS group. In the third phase, HR, MAP, LF, HF, and the LF/HF ratio were returned back to their baselines in both HS and Vag + HS groups. In the Vag + HS group, the VLF was lower and HR was higher than those in the other groups. Furthermore, blood gas parameters and lung histology indicated the impairment of gas exchange in the Vag + HS group.

CONCLUSIONS

The sympathetic activity is predominant in the first phase, whereas the parasympathetic activity is dominant in the second and third phases of hemorrhagic shock. There is an inverse relationship between the level of VLF and lung injury in vagotomized animals subjected to hemorrhagic shock.

Prognostic model for traumatic death due to bleeding: cross-sectional international study

OBJECTIVE

To develop and validate a prognostic model and a simple model to predict death due to bleeding in trauma patients.

DESIGN

Cross-sectional study with multivariable logistic regression using data from two large trauma cohorts.

SETTING

274 hospitals from 40 countries in the Clinical Randomisation of Anti-fibrinolytic in Significant Haemorrhage (CRASH-2) trial and 24 hospitals in the Northern French Alps Trauma registry.

PARTICIPANTS

13 485 trauma patients in the CRASH-2 trial and 9945 patients in the Northern French Alps Trauma registry who were admitted to hospital within 3 hours of injury.

MAIN OUTCOME MEASURE

In-hospital death due to bleeding within 28 days.

RESULTS

There were 815 (6%) deaths from bleeding in the CRASH-2 trial and 102 (1%) in the Northern French Alps Trauma registry. The full model included age, systolic blood pressure (SBP), Glasgow Coma Scale (GCS), heart rate, respiratory rate and type of injury (penetrating). The simple model included age, SBP and GCS. In a cross-validation procedure by country, discrimination and calibration were adequate (pooled C-statistic 0.85 (95% CI 0.81 to 0.88) for the full model and 0.84 (95% CI 0.80 to 0.88) for the simple model).

CONCLUSION

This prognostic model can identify trauma patients at risk of death due to bleeding in a wide range of settings and can support prehospital triage and trauma audit, including audit of tranexamic acid use.

Development and validation of a new simplified anatomic trauma mortality score

BACKGROUND

Most trauma mortality prediction scores are complex in nature. GAP (Glasgow Coma Scale, Age, Systolic blood pressure) and mGAP (mechanism, Glasgow Coma Scale, Age, Systolic blood pressure) scores are relatively simple scoring tools. However, these scores were not validated in low and middle income countries including Malaysia and its accuracies are influenced by the fluctuating physiologic parameters. This study aims to develop a relevant simplified anatomic trauma scoring system for the local trauma patients in Malaysia.

METHOD

A total of 3825 trauma patients from 2011 to 2016 were extracted from the Hospital Sultanah Aminah Trauma Surgery Registry. Patients were split into a development sample (n = 2683) and a validation sample (n = 1142). Univariate analysis is applied to identify significant anatomic predictors. These predictors were further analyzed using multivariable logistic regression to develop the new score and compared to existing score systems. The quality of prediction was determined regarding discrimination using sensitivity, specificity and receiver operating characteristic [ROC] curve.

RESULTS

Existing simplified score systems (GAP & mGAP) revealed areas under the ROC curve of 0.825 and 0.806. The newly developed HeCLLiP (Head, cervical spine, lung, liver, pelvic fracture) score combines only five anatomic components: injury involving head, cervical spine, lung, liver and pelvic bone. The probabilities of mortality can be estimated by charting the total score points onto a graph chart or using the cut-off value of (>2) with a sensitivity of 79.2 and specificity of 70.6% on the validation dataset. The HeCLLiP score achieved comparable values of 0.802 for the area under the ROC curve in validation samples.

CONCLUSION

HeCLLiP Score is a simplified anatomic score suited to the local Malaysian population with a good predictive ability for trauma mortality.

Injuries following motorcycle crashes at a level-1 trauma center in Riyadh

BACKGROUND

Motor vehicle crashes are the third leading cause of death in Saudi Arabia. Motorcycle riders, in particular, are considered more vulnerable than occupants, yet there are no previous studies that have examined the epidemiology of their injuries and outcomes in the country. Better understanding is needed to inform policymakers and guide future prevention programs.

OBJECTIVE

Describe patterns of injury among conscious and unconscious patients injured in motorcycle crashes.

DESIGN

Retrospective chart review.

SETTINGS

Level 1 trauma center in Riyadh.

PATIENTS AND METHODS

This retrospective study included all patients involved in motorcycle crashes who were admitted between 2001 and 2017. Medical records were reviewed, and data about injury characteristics, outcomes and healthcare utilization were ascertained.

MAIN OUTCOME MEASURES

Injury site and mortality rate.

SAMPLE SIZE AND CHARACTERISTICS

572 patients included 488 males (85.3%) and 232 <18 years of age (40.5%), mean (SD) age 21.1 (11.6) years.

RESULTS

About 3% of patients died either before or after admission. Extremity injuries (356, 62.2%) were most common followed by head injuries (229, 40%). Fifty-six (9%) suffered amputation, mostly to a lower limb.

CONCLUSION

This study underscores the significant burden of motorcycle-related injuries on population health of Saudi Arabia. The number of amputations due to motorcycle injuries is striking. Therefore, we need to increase enforcement of safety measures during recreational use of motorcycles and to raise awareness about the dangers of motorcycle crashes to improve traffic safety and ultimately population health.

LIMITATIONS

The study was conducted at a single hospital which may affect the generalizability of the data to the Saudi population.

CONFLICT OF INTEREST

None.

Prehospital administration of tranexamic acid in trauma patients: A 1:1 matched comparative study from a level 1 trauma center

PURPOSE

The purpose of this study was to test the efficacy of prehospital administration of tranexamic acid (TXA) to injured patients on mortality, thromboembolic events and need for blood transfusion in a level 1 trauma center.

METHODS

We conducted a retrospective study comparing adult trauma patients receiving or not receiving prehospital TXA between January 2017 and September 2018. Patients not receiving TXA but transfused within 4 h of admission were 1:1 matched to TXA-treated patients for age, sex, injury severity score, head abbreviated injury score, prehospital heart rate and systolic blood pressure.

RESULTS

In total 204 patients were included (102 TXA and 102 control), with a mean age of 31 years. On admission, shock index (p = 0.03) and serum lactate (p = 0.001) were greater in the control group, whereas the initial base deficit, hemoglobin levels and EMS time were comparable in both groups. The odd ratio (OR) for shock index ≥0.9 after TXA administration was 0.44 (95% CI 0.23-0.84). The median amount of blood transfusion was greater in the control group [eight units (range 1-40) vs three (range 0-40), p = 0.01] as well as the use of massive blood transfusion [OR 0.35 (95% CI 0.19-0.67)]. In the TXA group, VTE was higher [OR 2.0 (95% CI 0.37-11.40)]; whereas the overall mortality was lower [OR 0.78 (95% CI 0.42-1.45)] without reaching statistical significance.

CONCLUSIONS

Prehospital TXA administration is associated with less in-hospital blood transfusion and massive transfusion protocol (MTP). There is no significant increase in the thromboembolic events and mortality, however, further evaluation in larger clinical trials is needed.

PROBAST: A Tool to Assess Risk of Bias and Applicability of Prediction Model Studies: Explanation and Elaboration

Prediction models in health care use predictors to estimate for an individual the probability that a condition or disease is already present (diagnostic model) or will occur in the future (prognostic model). Publications on prediction models have become more common in recent years, and competing prediction models frequently exist for the same outcome or target population. Health care providers, guideline developers, and policymakers are often unsure which model to use or recommend, and in which persons or settings. Hence, systematic reviews of these studies are increasingly demanded, required, and performed. A key part of a systematic review of prediction models is examination of risk of bias and applicability to the intended population and setting. To help reviewers with this process, the authors developed PROBAST (Prediction model Risk Of Bias ASsessment Tool) for studies developing, validating, or updating (for example, extending) prediction models, both diagnostic and prognostic. PROBAST was developed through a consensus process involving a group of experts in the field. It includes 20 signaling questions across 4 domains (participants, predictors, outcome, and analysis). This explanation and elaboration document describes the rationale for including each domain and signaling question and guides researchers, reviewers, readers, and guideline developers in how to use them to assess risk of bias and applicability concerns. All concepts are illustrated with published examples across different topics. The latest version of the PROBAST checklist, accompanying documents, and filled-in examples can be downloaded from www.probast.org.

PROBAST: A Tool to Assess the Risk of Bias and Applicability of Prediction Model Studies

Clinical prediction models combine multiple predictors to estimate risk for the presence of a particular condition (diagnostic models) or the occurrence of a certain event in the future (prognostic models). PROBAST (Prediction model Risk Of Bias ASsessment Tool), a tool for assessing the risk of bias (ROB) and applicability of diagnostic and prognostic prediction model studies, was developed by a steering group that considered existing ROB tools and reporting guidelines. The tool was informed by a Delphi procedure involving 38 experts and was refined through piloting. PROBAST is organized into the following 4 domains: participants, predictors, outcome, and analysis. These domains contain a total of 20 signaling questions to facilitate structured judgment of ROB, which was defined to occur when shortcomings in study design, conduct, or analysis lead to systematically distorted estimates of model predictive performance. PROBAST enables a focused and transparent approach to assessing the ROB and applicability of studies that develop, validate, or update prediction models for individualized predictions. Although PROBAST was designed for systematic reviews, it can be used more generally in critical appraisal of prediction model studies. Potential users include organizations supporting decision making, researchers and clinicians who are interested in evidence-based medicine or involved in guideline development, journal editors, and manuscript reviewers.

Efficacy of prehospital administration of tranexamic acid in trauma patients: A meta-analysis of the randomized controlled trials

OBJECTIVE

Antifibrinolytic agent tranexamic acid (TXA) has a potential clinical benefit for in-hospital patients with severe bleeding but its effectiveness in pre-hospital settings remains unclear. We conducted a systematic review and meta-analysis to evaluate whether pre-hospital administration of TXA compared to placebo improve patients' outcomes?

METHODS

PubMed, MEDLINE, Cochrane Library, WHO International Clinical Trials Registry Platform, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, clinicaltrials.gov and Google scholar databases were searched for a retrospective, prospective and randomized (RCT) or quasi-RCT studies that assessed the effect of prehospital administration of TXA versus placebo on the outcomes of trauma patients with significant hemorrhage. The main outcomes of interest were 24hour 30-day mortality and in-hospital thromboembolic complications. Two authors independently abstracted the data using a data collection form. Results from different studies were pooled for the analysis, when appropriate.

RESULTS

Out of 92 references identified through the search, two analytical studies met the inclusion criteria. The effect of TXA on 24-hour mortality had a pooled odds ratio (OR) of 0.49 (95% CI 0.28-0.85), 30-day mortality OR of 0.86 (95% CI, 0.56-1.32), and thromboembolic events OR of 0.74 (95% CI, 0.27-2.07).

CONCLUSION

Prehospital TXA appears to reduce early mortality in trauma patients. The pooled analysis also shows a trend toward lower 30-day mortality and reduced risk of thromboembolic events. Additional randomized controlled clinical trials are needed to determine the significance of these trends.

Effect of treatment delay on the effectiveness and safety of antifibrinolytics in acute severe haemorrhage: a meta-analysis of individual patient-level data from 40 138 bleeding patients

BACKGROUND

Antifibrinolytics reduce death from bleeding in trauma and post-partum haemorrhage. We examined the effect of treatment delay on the effectiveness of antifibrinolytics.

METHODS

We did an individual patient-level data meta-analysis of randomised trials done with more than 1000 patients that assessed antifibrinolytics in acute severe bleeding. We identified trials done between Jan 1, 1946, and April 7, 2017, from MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, PubMed, Popline, and the WHO International Clinical Trials Registry Platform. The primary measure of treatment benefit was absence of death from bleeding. We examined the effect of treatment delay on treatment effectiveness using logistic regression models. We investigated the effect of measurement error (misclassification) in sensitivity analyses. This study is registered with PROSPERO, number 42016052155.

FINDINGS

We obtained data for 40 138 patients from two randomised trials of tranexamic acid in acute severe bleeding (traumatic and post-partum haemorrhage). Overall, there were 3558 deaths, of which 1408 (40%) were from bleeding. Most (884 [63%] of 1408) bleeding deaths occurred within 12 h of onset. Deaths from post-partum haemorrhage peaked 2-3 h after childbirth. Tranexamic acid significantly increased overall survival from bleeding (odds ratio [OR] 1·20, 95% CI 1·08-1·33; p=0·001), with no heterogeneity by site of bleeding (interaction p=0·7243). Treatment delay reduced the treatment benefit (p<0·0001). Immediate treatment improved survival by more than 70% (OR 1·72, 95% CI 1·42-2·10; p<0·0001). Thereafter, the survival benefit decreased by 10% for every 15 min of treatment delay until 3 h, after which there was no benefit. There was no increase in vascular occlusive events with tranexamic acid, with no heterogeneity by site of bleeding (p=0·5956). Treatment delay did not modify the effect of tranexamic acid on vascular occlusive events.

INTERPRETATION

Death from bleeding occurs soon after onset and even a short delay in treatment reduces the benefit of tranexamic acid administration. Patients must be treated immediately. Further research is needed to deepen our understanding of the mechanism of action of tranexamic acid.

FUNDING

UK NIHR Health Technology Assessment programme, Pfizer, BUPA Foundation, and J P Moulton Charitable Foundation (CRASH-2 trial). London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation (WOMAN trial).

Validation of the trauma mortality prediction scores from a Malaysian population

Background

Well-known trauma mortality prediction scores such as New Injury Severity Score (NISS), Revised Trauma Score (RTS), and Trauma and Injury Severity Score (TRISS) have been externally validated from high-income countries with established trauma databases. However, these scores were never used in Malaysian population. In this current study, we attempted to validate these scoring systems using our regional trauma surgery database.

Methods

A retrospective analysis of the regional Malaysian Trauma Surgery Database was performed over a period of 3 years from May 2011 to April 2014. NISS, RTS, Major Trauma Outcome Study (MTOS)-TRISS, and National Trauma Database (NTrD)-TRISS scores were recorded and calculated. Individual scoring system’s performance in predicting trauma mortality was compared by calculating the area under the receiver operating characteristic (AUC) curve. Youden index and associated optimal cutoff values for each scoring system was calculated to predict mortality. The corresponding positive predictive value, negative predictive value, and accuracy of the cutoff values were calculated.

Results

A total of 2208 trauma patients (2004 blunt and 204 penetrating injuries) with mean age of 36 (SD = 16) years were included. There were 239 deaths with a corresponding mortality rate of 10.8%. The AUC calculated for the NISS, RTS, MTOS-TRISS, and NTrD-TRISS were 0.878, 0.802, 0.812, and 0.848, respectively. The NISS score with a cutoff value of 24, sensitivity of 86.6% and specificity of 74.3%, outperformed the rest (p < 0.001). Mortality was predicted by NISS with an overall accuracy of 75.6%; its positive predictive value was at 29.02% and negative predictive value at 97.86%.

Conclusion

Amongst the four scores, the NISS score is the best trauma mortality prediction model suited for a local Malaysian trauma population. Further validation with multicentre data in the country may require to ascertain the finding.

Nano- and micro-materials in the treatment of internal bleeding and uncontrolled hemorrhage

Internal bleeding is defined as the loss of blood that occurs inside of a body cavity. After a traumatic injury, hemorrhage accounts for over 35% of pre-hospital deaths and 40% of deaths within the first 24 hours. Coagulopathy, a disorder in which the blood is not able to properly form clots, typically develops after traumatic injury and results in a higher rate of mortality. The current methods to treat internal bleeding and coagulopathy are inadequate due to the requirement of extensive medical equipment that is typically not available at the site of injury. To discover a potential route for future research, several current and novel treatment methods have been reviewed and analyzed. The aim of investigating different potential treatment options is to expand available knowledge, while also call attention to the importance of research in the field of treatment for internal bleeding and hemorrhage due to trauma.

The Tragically Hip: Trauma in Elderly Patients

Old age is a risk factor for poor outcome in trauma patients, as a result of undertriage and the presence of occult life-threatening injuries. The mechanisms of injury for geriatric trauma differ from those in younger patients, with a much higher incidence of low-impact trauma, especially falls from a low height. Frailty is a risk factor for severe injury after minor trauma, and caring for these patients require a multidisciplinary team with both trauma and geriatric expertise. With early recognition and aggressive management, severe injuries can still be associated with good outcomes, even in very elderly patients.

Ocular Myasthenia Gravis: Toward a Risk of Generalization Score and Sample Size Calculation for a Randomized Controlled Trial of Disease Modification

BACKGROUND

There is currently no prognostic test to determine the risk of developing generalized myasthenia gravis (GMG) risk in patients who first present with ocular disease. Most studies that report risk factors are flawed by the inclusion of patients on immunosuppression, which is likely to reduce the risk.

OBJECTIVE

To create a prognostic score to predict the risk of GMG.

METHODS

Multicenter retrospective cohort of patients with ocular myasthenia gravis for minimum 3 months, untreated with immunosuppression for minimum 2 years or until GMG onset.

RESULTS

One hundred one (57 female) patients were included, with median follow-up of 8.4 years (2-42) from disease onset. Thirty-one developed GMG at median of 1.31 years (3.5 months-20.2 years); 19 occurred within 2 years. Univariable logistic regression analysis produced 3 significant predictors (P < 0.10), adjusted odds ratios in a multivariable logistic model (χ P = 0.01) with multiple imputations for missing data: seropositivity, 5.64 (95% CI, 1.45-21.97); presence of 1 or more comorbidities including autoimmune disorders, 6.49 (95% CI, 0.78-53.90); thymic hyperplasia, 5.41 (95% CI, 0.39-75.43). Prognostic score was derived from the coefficients of the logistic model: sum of the points (1 point for the presence of each of the above predictive factors), classified "low risk" if ≤1 and "high risk" if ≥2. Predicted probabilities were 0.07 (SD, 0.03) for low risk and 0.39 (SD, 0.09) for high risk. Negative predictive value was 91% (95% CI, 79-98), positive predictive value was 38% (95% CI, 23-54), sensitivity was 79% (95% CI, 54-94), specificity was 63% (95% CI, 50-74), area under receiver operating characteristic curve was 0.74 (95% CI, 0.64-0.85).

CONCLUSIONS

In this preliminary study, we have shown by proof of principle that it is possible to stratify risk of GMG: an approach that may allow us to better counsel patients at diagnosis, complement decision-making, and move us toward addressing the question of modifying GMG risk in high-risk patients. Furthermore, the effect of comorbidities is novel and demands further elucidation.

Independent early predictors of mortality in polytrauma patients: a prospective, observational, longitudinal study

OBJECTIVES:

Trauma is an important public health issue and associated with substantial socioeconomic impacts and major adverse clinical outcomes. No single study has previously investigated the predictors of mortality across all stages of care (pre-hospital, emergency room, surgical center and intensive care unit) in a general trauma population. This study was designed to identify early predictors of mortality in severely injured polytrauma patients across all stages of care to provide a better understanding of the physiologic changes and mechanisms by which to improve care in this population.

METHODS:

A longitudinal, prospective, observational study was conducted between 2010 and 2013 in São Paulo, Brazil. Patients submitted to high-energy trauma were included. Exclusion criteria were as follows: injury severity score <16, <18 years old or insufficient data. Clinical and laboratory data were collected at four time points: pre-hospital, emergency room, and 3 and 24 hours after hospital admission. The primary outcome assessed was mortality within 30 days. Data were analyzed using tests of association as appropriate, nonparametric analysis of variance and generalized estimating equation analysis (p<0.05). ClinicalTrials.gov: NCT01669577.

RESULTS:

Two hundred patients were included. Independent early predictors of mortality were as follows: arterial hemoglobin oxygen saturation (p<0.001), diastolic blood pressure (p<0.001), lactate level (p<0.001), Glasgow Coma Scale score (p<0.001), infused crystalloid volume (p<0.015) and presence of traumatic brain injury (p<0.001).

CONCLUSION:

Our results suggest that arterial hemoglobin oxygen saturation, diastolic blood pressure, lactate level, Glasgow Coma Scale, infused crystalloid volume and presence of traumatic brain injury are independent early mortality predictors.

Magnitude and direction of missing confounders had different consequences on treatment effect estimation in propensity score analysis

OBJECTIVE

Propensity score (PS) analysis allows an unbiased estimate of treatment effects but assumes that all confounders are measured. We assessed the impact of omitting confounders from a PS analysis on clinical decision making.

STUDY DESIGN AND SETTING

We conducted Monte Carlo simulations on hypothetical observational studies based on virtual populations and on the population from a large randomized trial (CRASH-2). In both series of simulations, PS analysis was conducted with all confounders and with omitted confounders, which were defined to have different strengths of association with the outcome and treatment exposure. After inverse probability of treatment weighting, we calculated the absolute risk differences and numbers needed to treat (NNT).

RESULTS

In both series of simulations, omitting a confounder that was moderately associated with the outcome and exposure led to negligible bias on the NNT scale. The bias induced by omitting strongly positive confounding variables remained less than 15 patients to treat. Major bias and reversed effects were found only when omitting highly prevalent, strongly negative confounders that were similarly associated with the outcome and exposure with odds ratios greater than 4.00 (or <0.25). This omission was accompanied by a substantial decrease in analysis power.

CONCLUSION

The omission of strongly negative confounding variables from a PS analysis can lead to incorrect clinical decision making. However, omitting these variables also decreases the analysis power, which may prevent the reporting of significant but misleading effects.

Mitochondrial targeting by dichloroacetate improves outcome following hemorrhagic shock

Hemorrhagic shock is a leading cause of death in people under the age of 45 and accounts for almost half of trauma-related deaths. In order to develop a treatment strategy based on potentiating mitochondrial function, we investigated the effect of the orphan drug dichloroacetate (DCA) on survival in an animal model of hemorrhagic shock in the absence of fluid resuscitation. Hemorrhagic shock was induced in rats by withdrawing 60% of the blood volume and maintaining a hypotensive state. The studies demonstrated prolonged survival of rats subjected to hemorrhagic injury (HI) when treated with DCA. In separate experiments, using a fluid resuscitation model we studied mitochondrial functional alterations and changes in metabolic networks connected to mitochondria following HI and treatment with DCA. DCA treatment restored cardiac mitochondrial membrane potential and tissue ATP in the rats following HI. Treatment with DCA resulted in normalization of several metabolic and molecular parameters including plasma lactate and p-AMPK/AMPK, as well as Ach-mediated vascular relaxation. In conclusion we demonstrate that DCA can be successfully used in the treatment of hemorrhagic shock in the absence of fluid resuscitation; therefore DCA may be a good candidate in prolonged field care following severe blood loss.

Prognostic predictors of early mortality from exsanguination in adult trauma: a Malaysian trauma center experience

Background

Trauma mortality due to exsanguination is the second most common cause of death. The objective of this study is to investigate the predictors for early death from exsanguination.

Methods

A prognostic study was done to identify predictors of early mortality due to exsanguination. Data were extracted from our Trauma Surgery Registry database of Sultanah Aminah Hospital, Johor Bahru, Malaysia. All patients who were treated from May 1, 2011 to April 31, 2014 by the trauma team were included. Adult trauma patients included from the Trauma Surgery Registry were divided into two groups for analysis: early death from exsanguination and death from non-exsanguination/survivors. Univariate and multivariate analysis was performed to look for significant predictors of death from exsanguination. Variables analyzed were demography, mechanism of injury, organ injury scale, physiological parameters (systolic blood pressure (SBP), respiratory rate, heart rate, temperature), Glasgow Coma Scale (GCS), Revised Trauma Score (RTS), New Injury Severity Score (NISS), Trauma and Injury Severity Score (TRISS) and cause of death.

Results

A total of 2208 patients with an average age of 36 (±16) years were included. Blunt trauma was the majority with 90.5%, followed by penetrating injuries (9.2%). The overall mortality is 239 out of 2208 (10.8%). Seventy-eight patients (32.6%) died due to central nervous system injury, 69 due to sepsis (28.9%) and 58 due to exsanguination (24.3%). After multivariate analysis, age (OR 1.026 (1.009 to 1.044), p=0.002), SBP (OR 0.985 (0.975 to 0.995), p=0.003) and temperature (OR 0.203 (0.076 to 0.543), p=0.001) were found to be the significant physiological parameters. Intra-abdominal injury and NISS were significant anatomic mortality predictors from exsanguination (p<0.001). Patients with intra-abdominal injury had four times higher risk of mortality from exsanguination (OR 3.948 (2.331 to 6.686), p<0.001).

Discussion

In a Malaysian trauma center, age, SBP, core body temperature, intra-abdominal injury and NISS were significant predictors of early death from exsanguination.

Level of evidence

II.

Traumatic brain injuries in older adults-6 years of data for one UK trauma centre: retrospective analysis of prospectively collected data

OBJECTIVES

Our aim was to determine the incidence of traumatic brain injury (TBI) in older adults and investigate the relationship between injury characteristics and outcomes.

METHODS

Retrospective analysis of prospectively collected data submitted to Trauma Audit and Research Network (TARN) database for a major trauma centre in the West Midlands, UK, from 2008 to 2014. The Mayo Scale was used to categorise TBI. All patients were aged ≥65 years and were admitted with head or brain injuries meeting TARN inclusion criteria: injury resulting in immediate admission to hospital for 3 days, admitted to a high dependency area or death following trauma. We determined age, gender, mechanism of injury, Injury Severity Score, presenting Glasgow Coma Scale (GCS) and Mayo Score, and the association of outcome (Glasgow Outcome Scale (GOS)) with age and clinical presentation.

RESULTS

4413 patients were admitted with trauma meeting TARN criteria: 1389 were ≥65 years and 45% (624) had TBI. For patients ≥65 years with TBI, mean age was 79 (range 65-99); 56% were men. Falls accounted for 85% of all TBIs. Most TBIs were moderate/severe (80%) by the Mayo criteria. Of the 279 patients with subdural haematoma, 28% had neurosurgery. Most patients survived TBI (78%); 57% had a good outcome on GOS at discharge (not requiring care package). Mortality was associated with increased age (17% in ages 65-74 years, 19% in 75-84 years, 30% in ≥85 years, p=0.03). Outcome was significantly associated with injury severity (p=0.0001).

CONCLUSIONS

Patients with TBI represented 45% of all trauma cases meeting TARN inclusion criteria. Falls at home accounted for most TBIs. Most had moderate/severe TBI, yet over half made a good recovery on GOS. Our data indicate that injury prevention initiatives should focus on home safety. Further research is needed to examine rehabilitation and follow-up after hospital discharge.

Outcomes of road traffic injuries before and after the implementation of a camera ticketing system: a retrospective study from a large trauma center in Saudi Arabia

BACKGROUND

Road traffic injuries (RTIs) are the third leading cause of death in Saudi Arabia. Because speed is a major risk factor for severe crash-related injuries, a camera ticketing system was implemented countrywide in mid-2010 by the traffic police in an effort to improve traffic safety. There are no published studies on the effects of the system in Saudi Arabia.

OBJECTIVE

To examine injury severity and associated mortality at a large trauma center before and after the implementation of the ticketing system.

DESIGN

Retrospective, analytical.

SETTING

Trauma center of a tertiary care center in Riyadh.

PATIENTS AND METHODS

The study included all trauma registry patients seen in the emergency department for a crash-related injury (automobile occupants, pedestrians, or motorcyclists) between January 2005 and December 2014. Associations with outcome measures were assessed by univariate and multivariate methods.

MAIN OUTCOME MEASURE(S)

Injury severity score (ISS), Glasgow coma scale (GCS) and mortality.

RESULTS

The study included all trauma registry patients seen in the emergency department for a crash-related injury. All health outcomes improved in the period following implementation of the ticketing system. Following implementation, ISS scores decreased (-3.1, 95% CI -4.6, -1.6) and GCS increased (0.47, 95% CI 0.08, 0.87) after adjusting for other covariates. The odds of death were 46% lower following implementation than before implementation. When the data were log-transformed to account for skewed data distributions, the results remained statistically significant.

CONCLUSIONS

This study suggests positive health implications following the implementation of the camera ticketing system. Further investment in public health interventions is warranted to reduce preventable RTIs.

LIMITATIONS

The study findings represent a trauma center at a single hospital in Riyadh, which may not generalize to the Saudi population.

Validation of a novel prediction model for early mortality in adult trauma patients in three public university hospitals in urban India

BACKGROUND

Trauma is one of the top threats to population health globally. Several prediction models have been developed to supplement clinical judgment in trauma care. Whereas most models have been developed in high-income countries the majority of trauma deaths occur in low- and middle-income countries. Almost 20 % of all global trauma deaths occur in India alone. The aim of this study was to validate a basic clinical prediction model for use in urban Indian university hospitals, and to compare it with existing models for use in early trauma care.

METHODS

We conducted a prospective cohort study in three hospitals across urban India. The model we aimed to validate included systolic blood pressure and Glasgow coma scale. We compared this model with three additional models, which all have been designed for use in bedside trauma care, and two single variable models based on systolic blood pressure and Glasgow coma scale respectively. The outcome was early mortality, defined as death within 24 h from the time when vital signs were first measured. We compared the models in terms of discrimination, calibration, and potential clinical consequences using decision curve analysis. Multiple imputation was used to handle missing data. Performance measures are reported using their median and inter-quartile range (IQR) across imputed datasets.

RESULTS

We analysed 4440 patients, out of which 1629 were used as an updating sample and 2811 as a validation sample. We found no evidence that the basic model that included only systolic blood pressure and Glasgow coma scale had worse discrimination or potential clinical consequences compared to the other models. A model that also included heart had better calibration. For the model with systolic blood pressure and Glasgow coma scale the discrimination in terms of area under the receiver operating characteristics curve was 0.846 (IQR 0.841-0.849). Calibration measured by estimating a calibration slope was 1.183 (IQR 1.168-1.202). Decision curve analysis revealed that using this model could potentially result in 45 fewer unnecessary surveys per 100 patients.

CONCLUSIONS

A basic clinical prediction model with only two parameters may prove to be a feasible alternative to more complex models in contexts such as the Indian public university hospitals studied here. We present a colour-coded chart to further simplify the decision making in early trauma care.

Traumatic transfers: calibration is adversely affected when prediction models are transferred between trauma care contexts in India and the United States

OBJECTIVE

We evaluated the transferability of prediction models between trauma care contexts in India and the United States and explored updating methods to adjust such models for new contexts.

STUDY DESIGN AND SETTINGS

Using a combination of prospective cohort and registry data from 3,728 patients of Towards Improved Trauma Care Outcomes in India (TITCO) and from 18,756 patients of the US National Trauma Data Bank (NTDB), we derived models in one context and validated them in the other, assessing them for discrimination and calibration using systolic blood pressure, heart rate, and Glasgow coma scale as candidate predictors.

RESULTS

Early mortality was 8% in the TITCO and 1-2% in the NTDB samples. Both models discriminated well, but the TITCO model overestimated the risk of mortality in NTDB patients, and the NTDB model underestimated the risk in TITCO patients.

CONCLUSION

Transferability was good in terms of discrimination but poor in terms of calibration. It was possible to improve this miscalibration by updating the models' intercept. This updating method could be used in samples with as few as 25 events.

Pharmacological adjuncts to stop bleeding: options and effectiveness

Severe trauma and massive haemorrhage represent the leading cause of death and disability in patients under the age of 45 years in the developed world. Even though much advancement has been made in our understanding of the pathophysiology and management of trauma, outcomes from massive haemorrhage remain poor. This can be partially explained by the development of coagulopathy, acidosis and hypothermia, a pathological process collectively known as the “lethal triad” of trauma. A number of pharmacological adjuncts have been utilised to stop bleeding, with a wide variation in the safety and efficacy profiles. Antifibrinolytic agents in particular, act by inhibiting the conversion of plasminogen to plasmin, therefore decreasing the degree of fibrinolysis. Tranexamic acid, the most commonly used antifibrinolytic agent, has been successfully incorporated into most trauma management protocols effectively reducing mortality and morbidity following trauma. In this review, we discuss the current literature with regard to the management of haemorrhage following trauma, with a special reference to the use of pharmacological adjuncts. Novel insights, concepts and treatment modalities are also discussed.

Tranexamic acid in trauma: how should we use it?

Tranexamic acid (TXA) reduces blood loss by inhibiting the enzymatic breakdown of fibrin. It is often used in surgery to decrease bleeding and the need for blood transfusion. In 2011, results from a multi-center, randomized, and placebo-controlled trial (CRASH-2 trial) showed that TXA (1 g loading dose over 10 min followed by an infusion of 1 g over 8 h) safely reduces mortality in bleeding trauma patients. Initiation of TXA treatment within 3 h of injury reduces the risk of hemorrhage death by about one-third, regardless of baseline risk. Because it does not have any serious adverse effects, TXA can be administered to a wide spectrum of bleeding trauma patients. Limiting its use to the most severely injured or those with a diagnosis of 'hyperfibrinolysis' would result in thousands of avoidable deaths. A clinical trial (CRASH-3 trial) of TXA in patients with traumatic brain injury is now in progress.

Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD): explanation and elaboration

The TRIPOD (Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis) Statement includes a 22-item checklist, which aims to improve the reporting of studies developing, validating, or updating a prediction model, whether for diagnostic or prognostic purposes. The TRIPOD Statement aims to improve the transparency of the reporting of a prediction model study regardless of the study methods used. This explanation and elaboration document describes the rationale; clarifies the meaning of each item; and discusses why transparent reporting is important, with a view to assessing risk of bias and clinical usefulness of the prediction model. Each checklist item of the TRIPOD Statement is explained in detail and accompanied by published examples of good reporting. The document also provides a valuable reference of issues to consider when designing, conducting, and analyzing prediction model studies. To aid the editorial process and help peer reviewers and, ultimately, readers and systematic reviewers of prediction model studies, it is recommended that authors include a completed checklist in their submission. The TRIPOD checklist can also be downloaded from www.tripod-statement.org.