Multiple organ failure still a major cause of morbidity but not mortality in blunt multiple trauma

TBI related death has become the new epidemic in polytrauma: a 10-year prospective cohort analysis in severely injured patients

INTRODUCTION

Advances in trauma care have attributed to a decrease in mortality and change in cause of death. Consequently, exsanguination and traumatic brain injury (TBI) have become the most common causes of death. Exsanguination decreased by early hemorrhage control strategies, whereas TBI has become a global health problem. The aim of this study was to investigate trends in injury severity,physiology, treatment and mortality in the last decade.

METHODS

In 2014, a prospective cohort study was started including consecutive severely injured trauma patients > 15 years admitted to a Level-1 Trauma Center ICU. Demographics, physiology, resuscitation, and outcome parameters were prospectively collected.

RESULTS

Five hundred and seventy-eight severely injured patients with predominantly blunt injuries (94%) were included. Seventy-two percent were male with a median age of 46 (28-61) years, and ISS of 29 (22-38). Overall mortality rate was 18% (106/578) with TBI (66%, 70/106) being the largest cause of death. Less than 1% (5/578) died of exsanguination. Trend analysis of the 10-year period revealed similar mortality rates despite an ISS increase in the last 2 years. No significant differences in demographics,and physiology in ED were noted. Resuscitation strategy changed to less crystalloids and more FFP. Risk factors for mortality were age, brain injury severity, base deficit, hypoxia, and crystalloid resuscitation.

DISCUSSION

TBI was the single largest cause of death in severely injured patients in the last decade. With an aging population TBI will increase and become the next epidemic in trauma. Future research should focus on brain injury prevention and decreasing the inflammatory response in brain tissue causing secondary damage, as was previously done in other parts of the body.

Postinjury multiple organ failure in polytrauma: more frequent and potentially less deadly with less crystalloid

BACKGROUND

Recently, retrospective registry-based studies have reported the decreasing incidence and increasing mortality of postinjury multiple organ failure (MOF). We aimed to describe the current epidemiology of MOF following the introduction of haemostatic resuscitation.

METHODS

A 10-year prospective cohort study was undertaken at a Level-1 Trauma Centre-based ending in December 2015. Inclusion criteria age ≥ 16 years, Injury Severity Score (ISS) > 15, Abbreviated Injury Scale (AIS) Head < 3 and survived > 48 h. Demographics, physiological and shock resuscitation parameters were collected. The primary outcome was MOF defined by a Denver Score > 3.

SECONDARY OUTCOMES

intensive care unit length of stay (ICU LOS), ventilation days and mortality.

RESULTS

Three hundred and forty-seven patients met inclusion criteria (age 48 ± 20; ISS 30 ± 11, 248 (71%) were males and 23 (6.6%) patients died. The 74 (21%) MOF patients (maximum Denver Score: 5.5 ± 1.8; Duration; 5.6 ± 5.8 days) had higher ISS (32 ± 11 versus 29 ± 11) and were older (54 ± 19 versus 46 ± 20 years) than non-MOF patients. Mean daily Denver scores adjusted for age, sex, MOF and ISS did not change over time. Crystalloid usage decreased over the 10-year period (p value < 0.01) and PRBC increased (p value < 0.01). Baseline cumulative incidence of MOF at 28 days was 9% and competing risk analyses showed that incidence of MOF increased over time (subdistribution hazard ratio 1.14, 95% CI 1.04 to 1.23, p value < 0.01). Mortality risk showed no temporal change. ICU LOS increased over time (subdistribution hazard ratio 0.95, 95% CI 0.92 to 0.98, p value < 0.01). Ventilator days increased over time (subdistribution hazard ratio 0.94, 95% CI 0.9 to 0.97, p value < 0.01).

CONCLUSION

The epidemiology of MOF continues to evolve. Our prospective cohort suggests an ageing population with increasing incidence of MOF, particularly in males, with little changes in injury or shock parameters, who are being resuscitated with less crystalloids, stay longer on ICU without improvement in survival.

EVALUATION OF CYFRA 21-1, ANGIOPOETIN-2, PENTRAXIN-3, SRAGE, IL-6, AND IL-10 IN POLYTRAUMATIZED PATIENTS WITH CONCOMITANT THORACIC TRAUMA-HELPFUL MARKERS TO PREDICT PNEUMONIA?

ABSTRACT

Background: Pneumonia is a frequent complication after polytrauma. This study aims to evaluate the ability of different serum markers to identify patients at risk of developing pneumonia after polytrauma. Methods: A retrospective analysis of prospectively collected data in polytraumatized patients with concomitant thoracic trauma (Injury Severity Score ≥16, Abbreviated Injury Scale Thorax ≥ 3) was performed. The study cohort was divided into patients with and without pneumonia during the clinical course. Serum levels of lung epithelial (CYFRA 21-1), endothelial (Ang-2), and inflammatory (PTX-3, sRAGE, IL-6, IL-10) markers were measured upon arrival in the trauma room and on days 2 and 5. Results: A total of 73 patients and 16 healthy controls were included in this study. Of these, 20 patients (27.4%) developed pneumonia. Polytraumatized patients showed significantly increased CYFRA 21-1 levels with a distinct peak after admission compared with healthy controls. Serum PTX-3 significantly increased on day 2 in polytraumatized patients compared with healthy controls. Injury Severity Score and demographic parameters were comparable between both groups (pneumonia vs. no pneumonia). No statistically significant difference could be observed for serum levels of CYFRA 21-1, Ang-2, PTX-3, sRAGE, IL-6, and IL-10 between the groups (pneumonia vs. no pneumonia) on all days. Logistic regression revealed a combination of IL-6, IL-10, sRAGE, and PTX-3 to be eventually helpful to identify patients at risk of developing pneumonia and our newly developed score was significantly higher on day 0 in patients developing pneumonia ( P < 0.05). Conclusion: The investigated serum markers alone are not helpful to identify polytraumatized patients at risk of developing pneumonia, while a combination of IL-6, IL-10, PTX-3, and sRAGE might be.

Effect of Antithrombin III Administration on the Prognosis of Severe Trauma Patients with Disseminated Intravascular Coagulation

BACKGROUND

We aimed to investigate the effects of antithrombin III administration on the prognosis of severe trauma patients with disseminated intravascular coagulation (DIC).

METHODS

Medical records of a total of 4023 patients who were admitted to the intensive care unit (ICU) at the single regional trauma center from January 2016 to December 2020 were retrospectively analyzed. After the exclusion of young patients (<15 years old), mild trauma (ISS < 16), non DIC, etc., a total of 140 patients were included in the study. These patients were classified into antithrombin III-administered and non-antithrombin III-administered groups. Clinical data, including laboratory findings, trauma- and ICU-related severity scores, prognosis (including length of hospital stay), and need for organ support, were retrospectively collected. We evaluated the characteristics of the two groups, and compared and analyzed the vital signs, laboratory findings, prognosis, and clinical outcomes of each group. With this, we analyzed the effect of antithrombin III administration in severe trauma patients with DIC.

RESULTS

Of the 140 patients, 61 were treated with antithrombin III. No significant difference was observed in the baseline characteristics between the two groups for initial laboratory results, initial vital signs, or trauma-related severity scores. The improvement of the sequential organ failure assessment (SOFA) score, a prognostic marker, was significantly greater in the administered group (p = 0.009). Additionally, the antithrombin-administered group showed a larger improvement in the SOFA score than the non-administered group (p = 0.002). However, there was no statistical difference between the two groups for the frequency or duration of organ support treatments (renal replacement therapy, mechanical ventilation), mortality, or length of hospital stay.

CONCLUSION

Antithrombin III administration in severe trauma patients with DIC improved SOFA scores and aided in multi-organ dysfunction recovery. Appropriate indications should be studied to maximize the drug's improvement effect in patients with severe trauma in the future.

Dynamics of immune responses are inconsistent when trauma patients are grouped by injury severity score and clinical outcomes

The injury severity score (ISS) is used in daily practice to evaluate the severity of trauma patients; however, the score is not always consistent with the prognosis. After injury, systemic inflammatory response syndrome (SIRS) and compensatory anti-inflammatory response syndrome (CARS) are related to the prognosis of trauma patients. We aimed to evaluate the associations between the immune response and prognosis in trauma patients. Patients who admitted to the Trauma Intensive Care Unit (ICU) were eligible. Whole blood samples were collected at admission, and then 6, 12, 24, 48 and 72 h after admission. Natural killer (NK) cells, lymphocyte subset population and cytokines release were identified using flow cytometry. We grouped patients by their ISS (≤ 25 and > 25 as very severe injury) and ICU stay (≤ 10 days as a short ICU stay and > 10 days as a long ICU stay) for evaluation. Fifty-three patients were enrolled. ICU stay but not ISS was close correlated with activity daily living (ADL) at discharge. Patients with a long ICU stay had an immediate increase in NK cells followed by lymphopenia which persisted for 48 h. Immediate activation of CD8⁺ T cells and then exhaustion with a higher programmed cell death-1 (PD-1) expression and suppression of CD4⁺ T cells with a shift to an anti-inflammatory Th2 phenotype were also observed in the patients with a long ICU stay. When the patients were grouped by ISS, the dynamics of immune responses were inconsistent to those when the patients were grouped by ICU stay. Immune responses are associated with the prognosis of trauma patients, however the currently used clinical parameters may not accurately reflect immune responses. Further investigations are needed to identify accurate predictors of prognosis in trauma patients.

Evaluation of critical care burden following traumatic injury from two randomized controlled trials

Trauma resuscitation practices have continued to improve with new advances targeting prehospital interventions. The critical care burden associated with severely injured patients at risk of hemorrhage has been poorly characterized. We aim to describe the individual and additive effects of multiorgan failure (MOF) and nosocomial infection (NI) on delayed mortality and resource utilization. A secondary analysis of harmonized data from two large prehospital randomized controlled trials (Prehospital Air Medical Plasma (PAMPer) Trial and Study of Tranexamic Acid during Air and Ground Medical Prehospital Transport (STAAMP) Trial) was conducted. Only those patients who survived beyond the first 24 hours post-injury and spent at least one day in the ICU were included. Patients were stratified by development of MOF only, NI only, both, or neither and diagnosis of early (≤ 3 days) versus late MOF (> 3 days). Risk factors of NI and MOF, time course of these ICU complications, associated mortality, and hospital resource utilization were evaluated. Of the 869 patients who were enrolled in PAMPer and STAAMP and who met study criteria, 27.4% developed MOF only (n = 238), 10.9% developed NI only (n = 95), and 15.3% were diagnosed with both MOF and NI (n = 133). Patients developing NI and/or MOF compared to those who had an uncomplicated ICU course had greater injury severity, lower GCS, and greater shock indexes. Early MOF occurred in isolation, while late MOF more often followed NI. MOF was associated with 65% higher independent risk of 30-day mortality when adjusting for cofounders (OR 1.65; 95% CI 1.04-2.6; p = 0.03), however NI did not significantly affect odds of mortality. NI was individually associated with longer mechanical ventilation, ICU stay, hospital stay, and rehabilitation requirements, and the addition of MOF further increased the burden of inpatient and post-discharge care. MOF and NI remain common complications for those who survive traumatic injury. MOF is a robust independent predictor of mortality following injury in this cohort, and NI is associated with higher resource utilization. Timing of these ICU complications may reveal differences in pathophysiology and offer targets for continued advancements in treatment.

I-FABP as a Potential Marker for Intestinal Barrier Loss in Porcine Polytrauma

Polytrauma and concomitant hemorrhagic shock can lead to intestinal damage and subsequent multiple organ dysfunction syndrome. The intestinal fatty acid-binding protein (I-FABP) is expressed in the intestine and appears quickly in the circulation after intestinal epithelial cell damage. This porcine animal study investigates the I-FABP dynamics in plasma and urine after polytrauma. Furthermore, it evaluates to what extent I-FABP can also act as a marker of intestinal damage in a porcine polytrauma model. Eight pigs (Sus scrofa) were subjected to polytrauma which consisted of lung contusion, tibial fracture, liver laceration, and hemorrhagic shock followed by blood and fluid resuscitation and fracture fixation with an external fixator. Eight sham animals were identically instrumented but not injured. Afterwards, intensive care treatment including mechanical ventilation for 72 h followed. I-FABP levels in blood and urine were determined by ELISA. In addition, immunohistological staining for I-FABP, active caspase-3 and myeloperoxidase were performed after 72 h. Plasma and urine I-FABP levels were significantly increased shortly after trauma. I-FABP expression in intestinal tissue showed significantly lower expression in polytraumatized animals vs. sham. Caspase-3 and myeloperoxidase expression in the immunohistological examination were significantly higher in the jejunum and ileum of polytraumatized animals compared to sham animals. This study confirms a loss of intestinal barrier after polytrauma which is indicated by increased I-FABP levels in plasma and urine as well as decreased I-FABP levels in immunohistological staining of the intestine.

Neutrophil Gelatinase-associated Lipocalin Predicts Post-traumatic Acute Kidney Injury in Severely Injured Patients

BACKGROUND

Early detection of acute kidney injury (AKI) is crucial in the management of multiple-organ dysfunction syndrome in severely injured patients. Standard laboratory parameters usually increase with temporal delay. Therefore, we evaluated neutrophil gelatinase-associated lipocalin (NGAL) as an early marker for acute kidney injury.

PATIENTS AND METHODS

We retrospectively evaluated patients admitted to a level 1 trauma center. We collected clinicodemographic data and measured kidney-related factors and plasma cytokines.

RESULTS

A total of 39 patients were included. Patients with AKI had significantly higher levels not only of serum creatinine and urea, but also of NGAL (all p<0.001) than patients without AKI. The optimal NGAL cut-off value was determined to be 177 ng/ml, showing significant correlation with imminent or manifest AKI (p<0.001). Other independent markers correlated with AKI included pre-existing chronic kidney disease, use of catecholamines, and severe injury (p<0.001).

CONCLUSION

The serum level of NGAL is feasible early predictor of AKI.

Alterations of Phagocytic Activity and Capacity in Granulocytes and Monocytes Depend on the Pathogen Strain in Porcine Polytrauma

Background: Polytraumatized patients undergo a strong immunological stress upon insult. Phagocytes (granulocytes and monocytes) play a substantial role in immunological defense against bacteria, fungi and yeast, and in the clearance of cellular debris after tissue injury. We have reported a reduced monocytes phagocytic activity early after porcine polytrauma before. However, it is unknown if both phagocyte types undergo those functional alterations, and if there is a pathogen-specific phagocytic behavior. We characterized the phagocytic activity and capacity of granulocytes and monocytes after polytrauma.

Methods: Eight pigs (Sus scrofa) underwent polytrauma consisting of lung contusion, liver laceration, tibial fracture and hemorrhagic shock with fluid resuscitation and fracture fixation with external fixator. Intensive care treatment including mechanical ventilation for 72 h followed. Phagocytic activity and capacity were investigated using an in vitro ex vivo whole blood stimulation phagocytosis assays before trauma, after surgery, 24, 48, and 72 h after trauma. Blood samples were stimulated with Phorbol-12-myristate-13-acetate and incubated with FITC-labeled E. coli, S. aureus or S. cerevisiae for phagocytosis assessment by flow cytometry.

Results: Early polytrauma-induced significant increase of granulocytes and monocytes declined to baseline values within 24 h. Percentage of E. coli-phagocytizing granulocytes significantly decreased after polytrauma and during further intensive care treatment, while their capacity significantly increased. Interestingly, both granulocytic phagocytic activity and capacity of S. aureus significantly decreased after trauma, although a recovery was observed after 24 h and yet was followed by another decrease. The percentage of S. cerevisiae-phagocytizing granulocytes significantly increased after 24 h, while their impaired capacity after surgery and 72 h later was detected. Monocytic E. coli-phagocytizing percentage did not change, while their capacity increased after 24–72 h. After a significant decrease in S. aureus-phagocytizing monocytes after surgery, a significant increase after 24 and 48 h was observed without capacity alterations. No significant changes in S. cerevisiae-phagocytizing monocytes occurred, but their capacity dropped 48 and 72 h.

Conclusion: Phagocytic activity and capacity of granulocytes and monocytes follow a different pattern and significantly change within 72 h after polytrauma. Both phagocytic activity and capacity show significantly different alterations depending on the pathogen strain, thus potentially indicating at certain and possibly more relevant infection causes after polytrauma.

Global changes in mortality rates in polytrauma patients admitted to the ICU-a systematic review

Background

Many factors of trauma care have changed in the last decades. This review investigated the effect of these changes on global all-cause and cause-specific mortality in polytrauma patients admitted to the intensive care unit (ICU). Moreover, changes in trauma mechanism over time and differences between continents were analyzed.

Main body

A systematic review of literature on all-cause mortality in polytrauma patients admitted to ICU was conducted. All-cause and cause-specific mortality rates were extracted as well as trauma mechanism of each patient. Poisson regression analysis was used to model time trends in all-cause and cause-specific mortality.

Thirty studies, which reported mortality rates for 82,272 patients, were included and showed a decrease of 1.8% (95% CI 1.6–2.0%) in all-cause mortality per year since 1966. The relative contribution of brain injury-related death has increased over the years, whereas the relative contribution of death due to multiple organ dysfunction syndrome (MODS), acute respiratory distress syndrome, and sepsis decreased. MODS was the most common cause of death in North America, and brain-related death was the most common in Asia, South America, and Europe. Penetrating trauma was most often reported in North America and Asia.

Conclusions

All-cause mortality in polytrauma patients admitted to the ICU has decreased over the last decades. A shift from MODS to brain-related death was observed. Geographical differences in cause-specific mortality were present, which may provide region-specific learning possibilities resulting in improvement of global trauma care.

Neuroendocrine Modulation of the Immune Response after Trauma and Sepsis: Does It Influence Outcome?

Although the treatment of multiple-injured patients has been improved during the last decades, sepsis and multiple organ failure (MOF) still remain the major cause of death. Following trauma, profound alterations of a large number of physiological systems can be observed that may potentially contribute to the development of sepsis and MOF. This includes alterations of the neuroendocrine and the immune system. A large number of studies focused on posttraumatic changes of the immune system, but the cause of posttraumatic immune disturbance remains to be established. However, an increasing number of data indicate that the bidirectional interaction between the neuroendocrine and the immune system may be an important mechanism involved in the development of sepsis and MOF. The aim of this article is to highlight the current knowledge of the neuroendocrine modulation of the immune system during trauma and sepsis.

Risk Factors Associated With Early and Late Posttraumatic Multiorgan Failure: An Analysis From RETRAUCI

OBJECTIVE

To analyze factors associated with the development of early and late multiorgan failure (MOF) in trauma patients admitted to the intensive care unit (ICU).

METHODS

Spanish Trauma ICU Registry (RETRAUCI). Data collected from 52 trauma ICU between March 2015 and December 2019. We analyzed the incidence, outcomes, and the risk factors associated with early (< 72 h) or late (beyond 72 h) MOF in trauma ICU patients. Multiple logistic regression analysis was performed to analyze associated factors.

RESULTS

After excluding patients with incomplete data, 9,598 trauma ICU patients constituted the study population. Up to 965 patients (10.1%) presented with MOF, distributed by early MOF in 780 patients (8.1%) and late MOF in 185 patients (1.9%). The multivariate analysis showed that early MOF was associated with: ISS ≥ 16 (OR 2.80), hemodynamic instability (OR from 2.03 to 43.05), trauma-associated coagulopathy (OR 2.32), and acute kidney injury (OR 4.10). Late MOF was associated with: age > 65 years (OR 1.52), hemodynamic instability (OR from 1.92 to 9.94), acute kidney injury (OR 4.22), and nosocomial infection (OR 17.23). MOF was closely related to mortality (crude OR (95% CI) 4.77 (4.22-5.40)).

CONCLUSIONS

Multiorgan failure was recorded in 10% of trauma ICU patients, with early MOF being the predominant form. Early and late MOF forms were associated with different risk factors, suggesting different pathophysiological pathways. Early MOF was associated with higher severity of injury and severe bleeding-related complications and late MOF with advanced age and nosocomial infection.

Post-Traumatic Sepsis Is Associated with Increased C5a and Decreased TAFI Levels

Background: Sepsis frequently occurs after major trauma and is closely associated with dysregulations in the inflammatory/complement and coagulation system. Thrombin-activatable fibrinolysis inhibitor (TAFI) plays a dual role as an anti-fibrinolytic and anti-inflammatory factor by downregulating complement anaphylatoxin C5a. The purpose of this study was to investigate the association between TAFI and C5a levels and the development of post-traumatic sepsis. Furthermore, the predictive potential of both TAFI and C5a to indicate sepsis occurrence in polytraumatized patients was assessed. Methods: Upon admission to the emergency department (ED) and daily for the subsequent ten days, circulating levels of TAFI and C5a were determined in 48 severely injured trauma patients (injury severity score (ISS) ≥ 16). Frequency matching according to the ISS in septic vs. non-septic patients was performed. Trauma and physiologic characteristics, as well as outcomes, were assessed. Statistical correlation analyses and cut-off values for predicting sepsis were calculated. Results: Fourteen patients developed sepsis, while 34 patients did not show any signs of sepsis (no sepsis). Overall injury severity, as well as demographic parameters, were comparable between both groups (ISS: 25.78 ± 2.36 no sepsis vs. 23.46 ± 2.79 sepsis). Septic patients had significantly increased C5a levels (21.62 ± 3.14 vs. 13.40 ± 1.29 ng/mL; p < 0.05) and reduced TAFI levels upon admission to the ED (40,951 ± 5637 vs. 61,865 ± 4370 ng/mL; p < 0.05) compared to the no sepsis group. Negative correlations between TAFI and C5a (p = 0.0104) and TAFI and lactate (p = 0.0423) and positive correlations between C5a and lactate (p = 0.0173), as well as C5a and the respiratory rate (p = 0.0266), were found. In addition, correlation analyses of both TAFI and C5a with the sequential (sepsis-related) organ failure assessment (SOFA) score have confirmed their potential as early sepsis biomarkers. Cut-off values for predicting sepsis were 54,857 ng/mL for TAFI with an area under the curve (AUC) of 0.7550 (p = 0.032) and 17 ng/mL for C5a with an AUC of 0.7286 (p = 0.034). Conclusion: The development of sepsis is associated with early decreased TAFI and increased C5a levels after major trauma. Both elevated C5a and decreased TAFI may serve as promising predictive factors for the development of sepsis after polytrauma.

Predictive Value of Osteoprotegerin and Neutrophil Gelatinase-associated Lipocalin on Multiple Organ Failure in Multiple Trauma

BACKGROUND/AIM

Multiple organ dysfunction syndrome (MODS) is the leading cause of late posttraumatic mortality. This study analyzed the prognostic values of osteoprotegerin (OPG) and neutrophil gelatinase-associated lipocalin (NGAL/lipocalin 2) compared to interleukin-6 (IL-6) in multiply injured patients.

PATIENTS AND METHODS

A retrospective observational cohort study on multiply injured patients with an injury severity score (ISS) of ≥16 was performed. OPG, NGAL and IL-6 blood concentrations were measured. Statistical analysis comprised receiver-operating-characteristic (ROC) analysis with the corresponding area under the curve (AUC).

RESULTS

Thirty-nine patients with a mean ISS of 34±11 were included. Fourteen patients (36%) developed MODS and 8 patients (21%) died. Plasma levels of NGAL, OPG, and IL-6 were significantly elevated in the MODS+ group. Each biomarker positively correlated with MODS score and diagnosis of MODS.

CONCLUSION

NGAL and OPG might be indicative of MODS and could have the potential to be biomarkers in the early detection of patients at risk of posttraumatic MODS.

New considerations on pathways involved in acute traumatic coagulopathy: the thrombin generation paradox

Abstract

Background

An acute traumatic coagulopathy (ATC) is observed in about one third of severely traumatized patients. This early, specific, and endogenous disorder is triggered by the association of trauma and hemorrhage. The early phase of this condition is characterized by the expression of a bleeding phenotype leading to hemorrhagic shock and the late phase by a prothrombotic profile leading to multiple organ failure. The physiopathology of this phenomenon is still poorly understood. Hypotheses of disseminated intravascular coagulation, activated protein C-mediated fibrinolysis, fibrinogen consumption, and platelet functional impairment were developed by previous authors and continue to be debated. The objective of this study was to observe general hemostasis disorders in case of ATC to confront these hypotheses.

Method

Four groups of 15 rats were compared: C, control; T, trauma; H, hemorrhage; and TH, trauma and hemorrhage. Blood samples were drawn at baseline and 90 min. Thrombin generation tests, platelet aggregometry, and standard hemostasis tests were performed.

Results

Significant differences were observed between the baseline and TH groups for aPTT (17.9 ± 0.8 s vs 24.3 ± 1.4 s, p < 0.001, mean ± SEM), MAP (79.7 ± 1.3 mmHg vs 43.8 ± 1.3 mmHg, p < 0.001, mean ± SEM), and hemoglobin (16.5 ± 0.1 g/dL vs 14.1 ± 0.3 g/dL, p < 0.001, mean ± SEM), indicating the presence of an hemorrhagic shock due to ATC. Compared to all other groups, coagulation factor activities were decreased in the TH group, but endogenous thrombin potential was (paradoxically) higher than in group C (312 ± 17 nM/min vs. 228 ± 23 nM/min; p = 0.016; mean ± SEM). We also observed a subtle decrease in platelet count and function in case of ATC and retrieved an inversed linear relationship between fibrinogen concentration and aPTT (intercept, 26.53 ± 3.16; coefficient, − 3.40 ± 1.26; adjusted R²: 0.1878; p = 0.0123).

Conclusions

The clinical-biological profile that we observed, combining normal thrombin generation, fibrinogen depletion, and a hemorrhagic phenotype, reinforced the hypothesis of activated protein C mediated-fibrinolysis. The key role of fibrinogen, but not of the platelets, was confirmed in this study. The paradoxical preservation of thrombin generation suggests a protective mechanism mediated by rhabdomyolysis in case of major trauma. Based on these results, we propose a new conception concerning the pathophysiology of ATC.

Review of Animal Models of Comorbidities in Fracture-Healing Research

There is clinical evidence that patient-specific comorbidities like osteoporosis, concomitant tissue injury, and ischemia may strongly interfere with bone regeneration. However, underlying mechanisms are still unclear. To study these mechanisms in detail, appropriate animal models are needed. For decades, bone healing has been studied in large animals, including dogs, rabbits, pigs, or sheep. However, large animal models display a limited ability to study molecular pathways and cellular functions. Therefore in recent years, mice and rats have become increasingly popular as a model organism for fracture healing research due to the availability of molecular analysis tools and transgenic models. Both large and small animals can be used to study comorbidities and risk factors, modelling the human clinical situation. However, attention has to be paid when choosing an appropriate model due to species differences between large animals, rodents, and humans. This review focuses on large and small animal models for the common comorbidities ischemic injury/reduced vascularization, osteoporosis, and polytrauma, and critically discusses the translational and molecular aspects of these models. Here, we review material which was presented at the workshop "Animal Models of Comorbidities in Fracture Healing Research" at the 2019 ORS Annual Meeting in Austin Texas. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2491-2498, 2019.

Shock volume: Patient-specific cumulative hypoperfusion predicts organ dysfunction in a prospective cohort of multiply injured patients

BACKGROUND

Multiply injured patients are at risk of developing hemorrhagic shock and organ dysfunction. We determined how cumulative hypoperfusion predicted organ dysfunction by integrating serial Shock Index measurements.

METHODS

In this study, we calculated shock volume (SHVL) which is a patient-specific index that quantifies cumulative hypoperfusion by integrating abnormally elevated Shock Index (heart rate/systolic blood pressure ≥ 0.9) values acutely after injury. Shock volume was calculated at three hours (3 hr), six hours (6 hr), and twenty-four hours (24 hr) after injury. Organ dysfunction was quantified using Marshall Organ Dysfunction Scores averaged from days 2 through 5 after injury (aMODSD2-D5). Logistic regression was used to determine correspondence of 3hrSHVL, 6hrSHVL, and 24hrSHVL to organ dysfunction. We compared correspondence of SHVL to organ dysfunction with traditional indices of shock including the initial base deficit (BD) and the lowest pH measurement made in the first 24 hr after injury (minimum pH).

RESULTS

SHVL at all three time intervals demonstrated higher correspondence to organ dysfunction (R = 0.48 to 0.52) compared to initial BD (R = 0.32) and minimum pH (R = 0.32). Additionally, we compared predictive capabilities of SHVL, initial BD and minimum pH to identify patients at risk of developing high-magnitude organ dysfunction by constructing receiver operator characteristic curves. SHVL at six hours and 24 hours had higher area under the curve compared to initial BD and minimum pH.

CONCLUSION

SHVL is a non-invasive metric that can predict anticipated organ dysfunction and identify patients at risk for high-magnitude organ dysfunction after injury.

LEVEL OF EVIDENCE

Prognostic study, level III.

Development of multiple organ dysfunction syndrome in older and young adult trauma patients

Objective

We sought out to determine the correlation between the injury severity score (ISS) and multiple organ dysfunction syndrome (MODS) between severely injured young adults (18-54 years) and elderly (>55 years) patients.

Materials and Methods

This was a cross-sectional observational study. We included all adult cases (>18 years) diagnosed with trauma defined by the International Classification of Diseases, Ninth Revision. For significance testing, Chi-square test and odds ratio were used. Severe injuries were defined by an ISS >15. The presence of MODS was based on the definitions proposed by society for critical care medicine.

Results

A total of 469 young and 173 elderly patients were included in the study. Among the 469 young adults, 193 had ISS >15, whereas out of the 173 elderly patients, 88 had an ISS >15. Severely injured young and elderly groups were more likely to develop MODS compared with those with an ISS <15 (P < 0.001 and P < 0.001, respectively). The elderly had a higher likelihood of developing MODS (P < 0.001; odds ratio: 5.17; 95% confidence interval: 2.74-9.80).

Conclusion

This study demonstrated a direct relationship between an ISS >15 and the development of MODS. We also observed a five-fold increase in the development of MODS among severely injured elderly patients.

To select relevant features for longitudinal gene expression data by extending a pathway analysis method

The emerging field of pathway-based feature selection that incorporates biological information conveyed by gene sets/pathways to guide the selection of relevant genes has become increasingly popular and widespread. In this study, we adapt a gene set analysis method - the significance analysis of microarray gene set reduction (SAMGSR) algorithm to carry out feature selection for longitudinal microarray data, and propose a pathway-based feature selection algorithm - the two-level SAMGSR method. By using simulated data and a real-world application, we demonstrate that a gene's expression profiles over time can be considered as a gene set. Thus a suitable gene set analysis method can be utilized or modified to execute the selection of relevant genes for longitudinal omics data. We believe this work paves the way for more research to bridge feature selection and gene set analysis with the development of novel pathway-based feature selection algorithms.

Incidence and etiology of mortality in polytrauma patients in a Dutch level I trauma center

BACKGROUND

Earlier studies assessing mortality in polytrauma patients have focused on improving trauma care and reducing complications during hospital stay. The same studies have shown that the complication rate in these patients is high, often resulting in death. The aim of this study was to assess the incidence and causes of mortality in polytrauma patients in our institute. Secondarily, we assessed the donation and autopsy rates and outcome in these patients.

PATIENTS AND METHODS

All polytrauma patients (injury severity score≥16) transported to and treated in our institute during a period of 6 years were retrospectively analyzed. We included all patients who died during hospital stay. Prehospital and in-hospital data were collected on patients' condition, diagnostics, and treatment. The chance of survival was calculated according to the TRISS methodology. Patients were categorized according to the complications during treatment and causes of death. Logistic regression analysis was used to design a prediction model for mortality in major trauma. A statistical analysis was carried out.

RESULTS

Of the 1073 polytrauma patients who were treated in our institute during the study period, 205 (19.1%) died during hospital stay. The median age of the deceased patients was 58.8 years and 125 patients were men. Their mean injury severity score was 30.4. The most common mechanism of injury involved fall from height, followed by bicycle accidents. Almost 50% of the patients underwent an emergency intervention. Almost 92% of the total population died because of the effects of the accident (primary trauma). Of these, 24% died during primary assessment in the emergency department. Most patients died because of the effects of severe head injury (63.4%), followed by exsanguination (17.6%). The most common type of complications causing death during treatment was respiratory failure (6.3%), followed by multiple organ failure (1.5%). Autopsy was performed in 10.4%. Organ donation procedure was performed in 14.5%. Permission for donation was not provided in almost 20% of the population.

CONCLUSION

The mortality rate in polytrauma patients in our institute is considerable and comparable with the international literature. Most patients die because of the effects of the accident (primary trauma). Autopsy and organ donation rates are low in our institution and leave room for substantial improvements in the future.

Sepsis in the burn patient: a different problem than sepsis in the general population

Sepsis has recently been defined as "life-threatening organ dysfunction caused by a dysregulated host response to infection". A great amount of effort has been made to develop early treatments for sepsis through the Surviving Sepsis Campaign. There are similar but slightly different recommendations for the treatment of sepsis in the pediatric population. These international efforts have led to earlier diagnosis and treatments for sepsis that have led to improvements in survival. Sepsis is also the leading cause of death in the burn patient but most clinical sepsis studies have excluded burns. The reason for the exclusion is that the sepsis found in burn patients is different than that of the general population. The early treatment strategies, such as those directed by the Surviving Sepsis Campaign, focus on patients presenting to hospitals with recent signs of infection. Burn patients lose their primary barrier to infection, the skin, and thus the risk of infection persists as long as that barrier is absent. Efforts have been made to define sepsis, septic shock and infection in the burn population but there is constant need for revisions. One focus of this review is to discuss the differences in burn sepsis versus sepsis of the general population. Children often have profound responses to sepsis but can also make remarkable recoveries. This review will also explore problems specific to pediatric burns. The treatment of burns requires a continuous vigilance to watch for the subtle early signs of sepsis and then expeditious initiation of aggressive therapy. Strategies covering optimal management of pediatric burn sepsis will also be summarized.

Defining multiple organ failure after major trauma: A comparison of the Denver, Sequential Organ Failure Assessment, and Marshall scoring systems

BACKGROUND

Postinjury multiple organ failure (MOF) remains a significant cause of morbidity and mortality. A large number of scoring systems have been proposed to define MOF, with no criterion standard. The purpose of this study was to compare three commonly used scores: the Denver Postinjury Multiple Organ Failure Score, the Sequential Organ Failure Assessment (SOFA), and the Marshall Multiple Organ Dysfunction Score, by descriptive analysis of the populations described by each score, and their predictive ability for mortality.

METHODS

An observational cohort study was performed at a UK trauma center on major trauma patients requiring intensive care unit admission from 2003 to 2011. A novel trauma database was created, merging national audit data with local electronic monitoring systems. Data were collected on demographics, laboratory results, pharmacy, interventions, and hourly physiological monitoring. The primary outcome measure was mortality within 100 days from injury. Sensitivity analyses and receiver operating characteristic curves were used to assess the predictive ability of MOF scores for mortality.

RESULTS

In total, 491 patients were included in the trauma database. MOF incidence ranged from 22.8% (Denver) to 40.5% (Marshall) to 58.5% (SOFA). MOF definition did not affect timing of onset, but did alter duration and organ failure patterns. Overall mortality was 10.6%, with Denver MOF associated with the greatest increased risk of death (hazard ratio 3.87, 95% confidence interval, 2.24-6.66). No significant difference was observed in area under the receiver operating characteristic curve values between scores. Marked differences were seen in relative predictors, with Denver showing highest specificity (81%) and SOFA highest sensitivity (73%) for mortality.

CONCLUSION

The choice of MOF scoring system affects incidence, duration, organ dysfunction patterns, and mortality prediction. We would recommend use of the Denver score since it is simplest to calculate, identifies a high-risk group of patients, and has the strongest association with early trauma mortality.

LEVEL OF EVIDENCE

Epidemiological study, level III.

Artesunate Protects Against the Organ Injury and Dysfunction Induced by Severe Hemorrhage and Resuscitation

OBJECTIVE

To evaluate the effects of artesunate on organ injury and dysfunction associated with hemorrhagic shock (HS) in the rat.

BACKGROUND

HS is still a common cause of death in severely injured patients and is characterized by impairment of organ perfusion, systemic inflammatory response, and multiple organ failure. There is no specific therapy that reduces organ injury/dysfunction. Artesunate exhibits pharmacological actions beyond its antimalarial activity, such as anticancer, antiviral, and anti-inflammatory effects.

METHODS

Rats were submitted to HS. Mean arterial pressure was reduced to 30 mm Hg for 90 minutes, followed by resuscitation. Rats were randomly treated with artesunate (2.4 or 4.8 mg/kg i.v.) or vehicle upon resuscitation. Four hours later, parameters of organ injury and dysfunction were assessed.

RESULTS

Artesunate attenuated the multiple organ injury and dysfunction caused by HS. Pathway analysis of RNA sequencing provided good evidence to support an effect of artesunate on the Akt-survival pathway, leading to downregulation of interleukin-1 receptor-associated kinase 1. Using Western blot analysis, we confirmed that treatment of HS rats with artesunate enhanced the phosphorylation (activation) of Protein kinase B (Akt) and endothelial nitric oxide synthase and the phosphorylation (inhibition) of glycogen synthase kinase-3β (GSK-3β). Moreover, artesunate attenuated the HS-induced activation of nuclear factor kappa B and reduced the expression of proinflammatory proteins (inducible nitric oxide synthase, tumor necrosis factor-α, and interleukin 6).

CONCLUSIONS

Artesunate attenuated the organ injury/dysfunction associated with HS by a mechanism that involves the activation of the Akt-endothelial nitric oxide synthase survival pathway, and the inhibition of glycogen synthase kinase-3β and nuclear factor kappa B. A phase II clinical trial evaluating the effects of good manufacturing practice-artesunate in patients with trauma and severe hemorrhage is planned.

Postinjury Inflammation and Organ Dysfunction

The development of organ dysfunction (OD) is related to the intensity and balance between trauma-induced simultaneous, opposite inflammatory responses. Early proinflammation via innate immune system activation may cause early OD, whereas antiinflammation, via inhibition of the adaptive immune system and apoptosis, may induce immunoparalysis, impaired healing, infections, and late OD. Patients discharged with low-level OD may develop the persistent inflammation-immunosuppression catabolism syndrome. Although the incidence of multiple organ failure has decreased over time, it remains morbid, lethal, and resource intensive. However, single OD, especially acute lung injury, remains frequent. Treatment is limited, and prevention remains the mainstay strategy.

Large-magnitude Pelvic and Retroperitoneal Tissue Damage Predicts Organ Failure

BACKGROUND

Pelvic and retroperitoneal trauma is a major cause of morbidity and mortality in multiply injured patients. The Injury Severity Score (ISS) has been criticized for underrepresenting and inaccurately defining mechanical injury. The influence of pelvic injury volume on organ dysfunction and multiple organ failure (MOF) has not been described. Through the use of CT, this investigation sought to precisely define volumes of mechanical tissue damage by anatomic region and examine its impact on organ failure.

QUESTIONS/PURPOSES

(1) Do patients with MOF have a greater volume of pelvic and retroperitoneal tissue damage when compared with those without MOF? (2) In patients who sustained pelvic trauma, does the magnitude of pelvic injury differ in patients with MOF? (3) Does the magnitude of organ dysfunction correlate with pelvic tissue damage volume?

METHODS

Seventy-four multiply injured patients aged 18 to 65 years with an ISS ≥ 18 admitted to the intensive care unit for a minimum of 6 days with complete admission CT scans were analyzed. Each identifiable injury in the head/neck, chest, abdomen, and pelvis underwent volumetric determination using CT to generate regional tissue damage volume scores. Primary outcomes were the development of MOF as measured by the Denver MOF score and the degree of organ dysfunction by utilization of the Sequential Organ Failure Assessment (SOFA) score. Mean pelvic and retroperitoneal tissue damage volumes were compared in patients who developed MOF and those who did not develop MOF using Student's t-test. Among patients who sustained pelvic injuries, we compared mean volume of tissue damaged in patients who developed MOF and those who did not. We assessed whether there was a correlation between organ dysfunction, as measured by the SOFA score as a continuous variable, and the volume of pelvic and retroperitoneal tissue damage using the Pearson product-moment correlation coefficient.

RESULTS

The average volume of tissue damage was greater in patients with MOF when compared with those without (MOF: 685.667 ± 1081.344; non-MOF: 195.511 ± 381.436; mean difference 490.156 cc [95% confidence interval {CI}, 50.076-930.237 cc], p = 0.030). Among patients who sustained pelvic injuries, those with MOF had higher average tissue damage volumes than those without MOF (MOF: 1322.000 ± 1197.050; non-MOF: 382.750 ± 465.005; mean difference 939.250 [95% CI, 229.267-1649.233], p = 0.013). Organ dysfunction (SOFA score) correlated with higher volumes of pelvic tissue damage (r = 0.570, p < 0.001).

CONCLUSIONS

This investigation demonstrated that greater degrees of pelvic and retroperitoneal tissue damage calculated from injury CT scans in multiply injured patients is associated with more severe organ dysfunction and an increased risk of developing MOF. Early identification of polytrauma patients at risk of MOF allows clinicians to implement appropriate resuscitative strategies early in the disease course. Improved stratification of injury severity and a patient's anticipated clinical course may aid in the planning and execution of staged orthopaedic interventions. Future avenues of study should incorporate the ischemic/hypoperfusion component of pelvic injury in conjunction with the mechanical component presented here for improved stratification of multiply injured patients at higher risk of MOF.

LEVEL OF EVIDENCE

Level III, prognostic study.

Sugar or salt? The relative roles of the glucocorticoid and mineralocorticoid axes in traumatic shock

BACKGROUND

Glucocorticoid deficiency (GD) has been proposed as a key contributor to shock states, but the presence and role of acute mineralocorticoid deficiency may be of equal or greater significance. We sought to analyze the incidence and degree of acute mineralocorticoid deficiency and GD in an animal model of severe hemorrhage and shock.

METHODS

Fifty-seven swine underwent 35% volume-controlled hemorrhage followed by aortic cross-clamping for 50 minutes to induce truncal ischemia-reperfusion. Protocol-guided resuscitation was performed. Laboratory analysis included cortisol, aldosterone, and plasma renin activity. The aldosterone-to-renin ratio (ARR) was calculated at each time point, and changes were correlated to markers of perfusion.

RESULTS

Mean baseline cortisol levels were 5.8 μg/dL. Following hemorrhage, there was a significant increase in mean cortisol to 9.2 μg/dL (p < 0.001). After 1 hour of reperfusion, there was no change in mean cortisol levels (9.8 μg/dL, p = 0.12). Mean baseline aldosterone was 13.3 pg/mL. Aldosterone levels before cross-clamp removal increased significantly to 115.1 pg/mL (p < 0.001) and then rapidly declined to 49.2 pg/mL (p < 0.001) after 1 hour of reperfusion. Conversely, baseline plasma renin activity was 0.75 ng/mL per hour and increased significantly before cross-clamp removal (1.8) and at 1 hour (8.9, both p < 0.001). The ARR at baseline was 96.1 and increased to 113.5 (p = 0.68) before cross-clamp removal but significantly declined following 1 hour of reperfusion to 7.6 (p < 0.001). Overall, this represented a 93% reduction in mean ARR following reperfusion. The degree of aldosterone deficiency correlated with degree of systemic shock as measured by arterial base deficit (r = 0.47, p = 0.04), while cortisol showed no correlation.

CONCLUSION

Hemorrhagic shock with ischemia-reperfusion injury resulted in only modest impact on the glucocorticoid axis, but major dysfunction of the mineralocorticoid axis and severe hyperreninemic hypoaldosteronism. The degree of aldosterone deficiency may provide prognostic information or offer potential targets for pharmacologic intervention.

LEVEL OF EVIDENCE

Diagnostic study, level III.

Identification of potential biomarkers for post-traumatic complications released after trauma-hemorrhage from murine Kupffer cells and its investigation in lung and liver

CONTEXT

Early diagnosis of complications after severe trauma by specific biomarkers remains difficult.

OBJECTIVE

Identify potential new biomarkers for early diagnosis of post-traumatic complications.

MATERIAL AND METHODS

Mice underwent pressure-controlled hemorrhage or sham procedure. Four hours later, genome-wide expression of isolated Kupffer cells was compared with controls using Affymetrix-Genechip-Expression-Analysis and real-time-PCR.

RESULTS

Expression analysis and real-time-PCR revealed a significant increase of gene expression of Cxcl10, Il4ra, Csf2rb2, Lcn2, and Gbp5.

CONCLUSION

Cxcl10, Il4ra, Csf2rb2, Lcn2, and Gbp5 might represent new biomarkers for early diagnosis of post-traumatic complications, if they are linked to the development of post-traumatic complications.

Reducing acute respiratory distress syndrome occurrence using mechanical ventilation

The standard treatment for acute respiratory distress syndrome (ARDS) is supportive in the form of low tidal volume ventilation applied after significant lung injury has already developed. Nevertheless, ARDS mortality remains unacceptably high (> 40%). Indeed, once ARDS is established it becomes refractory to treatment, and therefore avoidance is key. However, preventive techniques and therapeutics to reduce the incidence of ARDS in patients at high-risk have not been validated clinically. This review discusses the current data suggesting that preemptive application of the properly adjusted mechanical breath can block progressive acute lung injury and significantly reduce the occurrence of ARDS.

Emergency General Surgery: Defining Burden of Disease in the State of Maryland

Acute care surgery services continue expanding to provide emergency general surgery (EGS) care. The aim of this study is to define the characteristics of the EGS population in Maryland. Retrospective review of the Health Services Cost Review Commission database from 2009 to 2013 was performed. American Association for the Surgery of Trauma-defined EGS ICD-9 codes were used to define the EGS population. Data collected included patient demographics, admission origin [emergency department (ED) versus non-ED], length of stay (LOS), mortality, and disposition. There were 3,157,646 encounters. In all, 817,942 (26%) were EGS encounters, with 76 per cent admitted via an ED. The median age of ED patients that died was 74 years versus 61 years for those that lived ( P < 0.001). Twenty one per cent of ED admitted patients had a LOS > 7 days. Of 78,065 non-ED admitted patients, the median age of those that died was 68 years versus 59 years for those that lived ( P < 0.001). Twenty eight per cent of non-ED admits had LOS > 7 days. In both ED and non-ED patients, there was a bimodal distribution of death, with most patients dying at LOS ≤ 2 or LOS > 7 days. In this study, EGS diagnoses are present in 26 per cent of inpatient encounters in Maryland. The EGS population is elderly with prolonged LOS and a bimodal distribution of death.

Time-based trauma-related mortality patterns in a newly created trauma system

BACKGROUND

Data on time-based trauma mortality (TTM) patterns in developing countries are lacking.

OBJECTIVE

Our objective was to analyze the TTM in a newly established trauma center.

METHODS

A retrospective analysis of all trauma-related mortality between 2010 and 2012 was conducted in Qatar. Based on the time of injury, deceased cases were categorized into immediate (pre-hospital), early (first 24 h), and late (>24 h) groups. TTM was analyzed and compared.

RESULTS

A total of 4,966 trauma patients were admitted to the trauma center over 3 years; of them, 333 trauma-related deaths (6.8 %) were documented and reviewed. The death pattern peaked immediately post-trauma (n = 142), followed by 96 deaths within the first 24 h, 19 deaths within the time period >24 to 48 h, 50 deaths within the 3rd and 7th day (second peak), and 26 deaths after the 1st week. The majority of the deceased were males, with a mean age of 36 ± 17 years. Motor vehicle crashes (43.5 %) were the commonest mechanism of injury. At presentation, median injury severity score (ISS) was 32 (range 9-75). Bleeding, abdominal, and pelvic injuries were higher in the early group, whereas head injuries were observed more in the late mortality group. Co-morbidities and in-hospital complications were predominantly encountered in the late group. Head injury (odds ratio [OR] 3.760; 95 % confidence interval [CI] 1.311-10.797) was an independent predictor for late death, whereas the need for blood transfusion was a predictor for early death (OR 3.233; 95 % CI 1.125-9.345).

CONCLUSION

The distribution of mortality shows a bimodal pattern. The high rate of death at the scene highlights the importance of pre-hospital care and the need for injury prevention programs.

Risk factors for trauma-induced coagulopathy- and transfusion-associated multiple organ failure in severely injured trauma patients

Background

Both trauma-induced coagulopathy (TIC) and transfusion strategies influence early outcome in hemorrhagic trauma patients. Their impact on late outcome is less well characterized. This study systematically reviews risk factors for TIC- and transfusion-associated multiple organ failure (MOF) in severely injured trauma patients.

Materials and methods

A systematic search was conducted in PubMed and Embase. Studies published from 1986 to 2013 on adult trauma patients with an injury severity score ≥16, investigating TIC or transfusion strategies with MOF as primary or secondary outcome, were eligible for inclusion. Results of the included studies were evaluated with meta-analyses of pooled data.

Results

In total, 50 studies were included with a total sample size of 63,586 patients. Due to heterogeneity of the study populations and outcome measures, results from 7 studies allowed for pooling of data. Risk factors for TIC-associated MOF were hypocoagulopathy, hemorrhagic shock, activated protein C, increased histone levels, and increased levels of markers of fibrinolysis on admission. After at least 24 h after admission, the occurrence of thromboembolic events was associated with MOF. Risk factors for transfusion-associated MOF were the administration of fluids and red blood cell units within 24 h post-injury, the age of red blood cells (>14 days) and a ratio of FFP:RBC ≥ 1:1 (OR 1.11, 95% CI 1.04–1.19).

Conclusion

Risk factors for TIC-associated MOF in severely injured trauma patients are early hypocoagulopathy and hemorrhagic shock, while a hypercoagulable state with the occurrence of thromboembolic events later in the course of trauma predisposes to MOF. Risk factors for transfusion-associated MOF include administration of crystalloids and red blood cells and a prolonged storage time of red blood cells. Future prospective studies investigating TIC- and transfusion-associated risk factors on late outcome are required.

Peri-operative changes in serum immune markers after trauma: a systematic review

INTRODUCTION

Surgery is a posttraumatic immune stimulus which contributes to the systemic inflammatory response syndrome and multiple organ failure (MOF). Serum markers may facilitate post-injury immune monitoring, predict complications and guide the timing of surgery.

AIM

To evaluate whether immune markers increase after surgery in trauma patients, if this is affected by the timing of surgery, and whether immune markers correlate with clinical outcomes.

PATIENTS AND METHODS

Systematic review of MEDLINE, Cochrane and EMBASE using a combination of keywords including trauma, biological markers, immune monitoring, and surgical procedures. The last search was performed on 26/11/13. The search considered English language studies enrolling adult trauma patients. Outcomes were perioperative immune markers plus clinical outcomes including mortality, MOF, sepsis.

RESULTS

1612 Articles were identified using the search strategy. 1548 Articles were excluded by title and 40 excluded by abstract, leaving 24 articles for full text review. Of these articles, fifteen studies were eligible for study inclusion. The disparity in interventions and outcome measures precluded combined statistical analysis. The surgical intervention studied was mostly intramedullary nailing of long bone fractures. All articles described a postoperative increase in at least one marker. Interleukin (IL)-6 and IL-10 were consistently elevated and tested in the greatest number of patients. Many studies did not correlate markers with clinical outcomes and few significant associations were demonstrated. Two studies considered the timing of surgery and showed greater increase in IL-6 after "early" surgery, though definitions of timing were dissimilar.

DISCUSSION

An increase in posttraumatic serum cytokines has been demonstrated after surgery, but without consistent clinical associations. The timing of surgery may modulate this increase. Future research directions include confirmation of findings in larger populations, clarifying clinical associations, and evaluation of other surgical interventions.

Temporal trends of postinjury multiple-organ failure: still resource intensive, morbid, and lethal

BACKGROUND

While the incidence of postinjury multiple-organ failure (MOF) has declined during the past decade, temporal trends of its morbidity, mortality, presentation patterns, and health care resources use have been inconsistent. The purpose of this study was to describe the evolving epidemiology of postinjury MOF from 2003 to 2010 in multiple trauma centers sharing standard treatment protocols.

METHODS

"Inflammation and Host Response to Injury Collaborative Program" institutions that enrolled more than 20 eligible patients per biennial during the 2003 to 2010 study period were included. The patients were aged 16 years to 90 years, sustained blunt torso trauma with hemorrhagic shock (systolic blood pressure < 90 mm Hg, base deficit ≥ 6 mEq/L, blood transfusion within the first 12 hours), but without severe head injury (motor Glasgow Coma Scale [GCS] score < 4). MOF temporal trends (Denver MOF score > 3) were adjusted for admission risk factors (age, sex, body max index, Injury Severity Score [ISS], systolic blood pressure, and base deficit) using survival analysis.

RESULTS

A total of 1,643 patients from four institutions were evaluated. MOF incidence decreased over time (from 17% in 2003-2004 to 9.8% in 2009-2010). MOF-related death rate (33% in 2003-2004 to 36% in 2009-2010), intensive care unit stay, and mechanical ventilation duration did not change over the study period. Adjustment for admission risk factors confirmed the crude trends. MOF patients required much longer ventilation and intensive care unit stay, compared with non-MOF patients. Most of the MOF-related deaths occurred within 2 days of the MOF diagnosis. Lung and cardiac dysfunctions became less frequent (57.6% to 50.8%, 20.9% to 12.5%, respectively), but kidney and liver failure rates did not change (10.1% to 12.5%, 15.2% to 14.1%).

CONCLUSION

Postinjury MOF remains a resource-intensive, morbid, and lethal condition. Lung injury is an enduring challenge and should be a research priority. The lack of outcome improvements suggests that reversing MOF is difficult and prevention is still the best strategy.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

Early application of airway pressure release ventilation may reduce mortality in high-risk trauma patients: a systematic review of observational trauma ARDS literature

BACKGROUND

Adult respiratory distress syndrome is often refractory to treatment and develops after entering the health care system. This suggests an opportunity to prevent this syndrome before it develops. The objective of this study was to demonstrate that early application of airway pressure release ventilation in high-risk trauma patients reduces hospital mortality as compared with similarly injured patients on conventional ventilation.

METHODS

Systematic review of observational data in patients who received conventional ventilation in other trauma centers were compared with patients treated with early airway pressure release ventilation in our trauma center. Relevant studies were identified in a PubMed and MEDLINE search from 1995 to 2012 and included prospective and retrospective observational and cohort studies enrolling 100 or more adult trauma patients with reported adult respiratory distress syndrome incidence and mortality data.

RESULTS

Early airway pressure release ventilation as compared with the other trauma centers represented lower mean adult respiratory distress syndrome incidence (14.0% vs. 1.3%) and in-hospital mortality (14.1% vs. 3.9%).

CONCLUSION

These data suggest that early airway pressure release ventilation may prevent progression of acute lung injury in high-risk trauma patients, reducing trauma-related adult respiratory distress syndrome mortality.

LEVEL OF EVIDENCE

Systematic review, level IV.

Benchmarking the incidence of organ failure after injury at trauma centers and nontrauma centers in the United States

BACKGROUND

Organ failure after injury is a significant cause of morbidity and mortality, yet its true incidence is unknown. We sought to benchmark the incidence of organ failure following injury at trauma centers and nontrauma centers using a nationally representative sample of hospital discharges. We hypothesized that injured patients receiving care at trauma centers would have a lower incidence of organ failure than those at nontrauma centers.

METHODS

We used the 2006 Nationwide Inpatient Sample to identify injured adults (age ≥ 15 years) with organ dysfunction using specific DRG International Classification of Diseases-9th Rev. codes by system. After adjusting for hospital size, geographic region, comorbidities, Injury Severity Score (ISS), age, and sex, a multivariate logistic regression model was created to compare rates of organ dysfunction between trauma centers and nontrauma centers.

RESULTS

We identified 396,276 injured patients, representing the patient care experience of a total of 1,939,473 patients. Among these patients, 6.5% had concurrent organ failure. Injured patients who had acute organ failure were more likely to die than injured patients without organ failure (12.4% vs. 1.7%, p < 0.001). Mortality increased with the number of organ system failures. Patients treated at trauma centers had a higher incidence of respiratory and cardiac failure compared with nontrauma centers.

CONCLUSION

We offer the first national benchmark of rates of acute organ failure among injured patients. Postinjury organ failure is uncommon, but incidence increases with injury severity and correlates with mortality. Patients at trauma centers had higher rates of respiratory and cardiac failure, possibly representing differences in referral patterns or resuscitation strategies.

LEVEL OF EVIDENCE

Prognostic and epidemiologic study, level III.

Changes in the epidemiology and prediction of multiple-organ failure after injury

BACKGROUND

The epidemiology of multiple-organ failure (MOF) after injury has been changing, questioning the validity of previously described prediction models. This study aimed to describe the current epidemiology of MOF. The secondary aim was development of a prediction model that could be used for early identification of patients at risk of MOF.

METHODS

A 60-month prospective epidemiologic study was undertaken at an Australian Level I trauma center. Data were collected on trauma patients that met inclusion criteria (intensive care unit [ICU] admission; Injury Severity Score [ISS] > 15; age > 18 years, head Abbreviated Injury Scale [AIS] score < 3; and survival for >48 hours). Demographics, injury severity (ISS), physiologic parameters, MOF status based on the Denver score, and outcome data were prospectively collected. Univariate analysis and multivariate logistic modeling were performed; p < 0.05 was considered significant. Data are presented as percentage or mean (SD).

RESULTS

A total of 140 patients met the inclusion criteria (age, 47 [21] years; ISS, 30 [11]; male, 69%), 21 patients (15%) developed MOF, and MOF associated mortality was 24% versus non-MOF mortality rate of 3%. Patients who developed MOF had longer ICU stays (19 [7] vs. 7 [5], p < 0.01) and had more ventilator days (18 [9] vs. 4 [4], p < 0.01). Prediction models were generated at two time points as follows: admission and 24 hours after injury. At admission, age (>65 years) and admission platelet count (<150 × 10(9)/L) were significant predictors of MOF; at 24 hours after injury, MOF was predicted by age more than 65 years, admission platelet count less than 150 × 10(9)/L, maximum creatinine of greater than 150 × 10(9)/L and minimum bilirubin of greater than 10 × 10(9)/L. Shock parameters and injury severity did not predict MOF.

CONCLUSION

The incidence of MOF (15%) is lower than reported 15 years ago; MOF remains a major cause of ICU resource use and late mortality after injury. The independent predictors of MOF have fundamentally changed, likely owing to improvements in resuscitation and critical care. Current predictors are universally available at admission and 24 hours.

LEVEL OF EVIDENCE

Epidemiologic/prognostic study, level III.

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.

Clinical review: Statins and trauma--a systematic review

Statins, in addition to their lipid-lowering properties, have anti-inflammatory actions. The aim of this review is to evaluate the effect of pre-injury statin use, and statin treatment following injury. MEDLINE, EMBASE, and CENTRAL databases were searched to January 2012 for randomised and observational studies of statins in trauma patients in general, and in patients who have suffered traumatic brain injury, burns, and fractures. Of 985 identified citations, 7 (4 observational studies and 3 randomised controlled trials (RCTs)) met the inclusion criteria. Two studies (both observational) were concerned with trauma patients in general, two with patients who had suffered traumatic brain injury (one observational, one RCT), two with burns patients (one observational, one RCT), and one with fracture healing (RCT). Two of the RCTs relied on surrogate outcome measures. The observational studies were deemed to be at high risk of confounding, and the RCTs at high risk of bias. Three of the observational studies suggested improvements in a number of clinical outcomes in patients taking statins prior to injury (mortality, infection, and septic shock in burns patients; mortality in trauma patients in general; mortality in brain injured patients) whereas one, also of trauma patients in general, showed no difference in mortality or infection, and an increased risk of multi-organ failure. Two of three RCTs on statin treatment in burns patients and brain injured patients showed improvements in E-selectin levels and cognitive function. The third, of patients with radial fractures, showed no acceleration in fracture union. In conclusion, there is some evidence that pre-injury statin use and post-injury statin treatment may have a beneficial effect in patients who have suffered general trauma, traumatic brain injury, and burns. However, these studies are at high risk of confounding and bias, and should be regarded as 'hypothesisgenerating'. A well-designed RCT is required to determine the therapeutic efficacy in improving outcomes in this patient population.

Cause of death and time of death distribution of trauma patients in a Level I trauma centre in the Netherlands

OBJECTIVE

The classical trimodal distribution of trauma deaths describes three peaks of deaths following trauma: immediate, early and late deaths. The aim of this study was to evaluate whether further maturation of the trauma centre and the improvement of survival have had an effect on the time of death distribution and resulted in a shift in causes of death.

METHODS

All trauma patients from 1999 to 2010 who died after arrival in the emergency room and prior to discharge from the hospital were included. Deaths caused by drowning, poisoning and overdose were excluded.

RESULTS

A total of 16,421 trauma patients were admitted to our hospital. 772 (4.7 %) patients died, of which 720 were included in this study. The trauma mechanism was predominantly blunt (94.7 %). 530 patients (73.6 %) had Injury Severity Score (ISS) ≥25. The most frequent causes of death were central nervous system (CNS) injury (59.9 %), exsanguinations (12.9 %) and pneumonia/respiratory insufficiency (8.5 %). The first peak of death was seen in the first hour after arrival at the emergency department; subsequently, a rapid decline was observed and no further peaks were seen. Over the years, we observed a general decrease in deaths due to exsanguination (p = 0.035) and a general increase in deaths due to CNS injury (p = 0.004).

CONCLUSION

The temporal distribution of trauma deaths in our hospital changed as maturation of the trauma centre occurred. There is one peak of trauma deaths in the first hour after admission, followed by a rapid decline; no trimodal distribution was observed. Over time, there was a decrease in exsanguinations and an increase of deaths due to CNS injury.

Heparin-binding protein (HBP): an early marker of respiratory failure after trauma?

BACKGROUND

Trauma and its complications contribute to morbidity and mortality in the general population. Trauma victims are susceptible to acute respiratory distress syndrome (ARDS) and sepsis. Polymorphonuclear leucocytes (PMNs) are activated after trauma and there is substantial evidence of their involvement in the development of ARDS. Activated PMNs release heparin-binding protein (HBP), a granule protein previously shown to be involved in acute inflammatory reactions. We hypothesised that there is an increase in plasma HBP content after trauma and that the increased levels are related to the severity of the trauma or later development of severe sepsis and organ failure (ARDS).

METHODS AND MATERIAL

We investigated HBP in plasma samples within 36 h from trauma in 47 patients admitted to a level one trauma centre with a mean injury severity score (ISS) of 26 (21-34). ISS, admission sequential organ failure assessment (SOFA) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores were recorded at admission. ARDS and presence of severe sepsis were determined daily during intensive care.

RESULTS

We found no correlation between individual maximal plasma HBP levels at admission and ISS, admission SOFA or APACHE II. We found, however, a correlation between HBP levels and development of ARDS (P = 0.026, n = 47), but not to severe sepsis.

CONCLUSION

HBP is a potential biomarker candidate for early detection of ARDS development after trauma. Further research is required to confirm a casual relationship between plasma HBP and the development of ARDS.

Infections after trauma are associated with subsequent cardiac injury

BACKGROUND

Trauma produces profound inflammatory and immune responses. A second hit such as an infection further disrupts the inflammatory cascade. Inflammatory responses, following traumatic injuries, infections, or both, are emerging as biologic mediators of cardiac disease including myocardial ischemia and infarction. Inflammation-induced and stress-related cardiac damage are increasingly recognized in patients with critical illness. It is believed that cardiac dysfunction is the result of alterations in the inflammatory and immune cascades. Urinary tract infections (UTIs) and ventilator-associated pneumonia (VAP) are associated with increased mortality in trauma patients. UTIs and VAPs induced inflammatory responses. We postulate that increased mortality seen in trauma patients with infections is caused by increased rates of cardiac injury.

METHODS

This is a retrospective review of prospectively collected data. All trauma patients admitted to the intensive care unit at our Level I trauma center during 5 years were included in the analysis. Proportional hazard regression analysis was performed to predict suspicion of cardiac injury (troponin ordered), any cardiac injury (troponin > 0.15 ng/mL), or severe cardiac injury (troponin > 1 ng/mL) using age, sex, Injury Severity Score (ISS), pulmonary disease (chronic obstructive pulmonary disease), heart failure, hypertension, diabetes, and the presence of a UTI or VAP. A similar proportion hazard regression was performed to predict mortality.

RESULTS

In the model to predict any cardiac injury, chronic obstructive pulmonary disease (hazards ratio [HR], 1.9; p = 0.02), ISS (HR, 1.01; p = 0.04), VAP (HR, 5.6; p < 0.01), and UTI (HR, 2.4; p = 0.03) were significant. Neither VAP nor UTI predicted severe cardiac injury. In the model to predict death, any cardiac injury was not associated with mortality, but severe cardiac injury and UTI were associated with mortality as age increased.

CONCLUSION

Infectious complications have been associated with increased mortality in trauma patients. Our data demonstrate that development of VAP or UTI is associated with an increased risk of developing cardiac injury in trauma patients, which may contribute to subsequent increased mortality.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level III.

Relationship between age/gender-induced survival changes and the magnitude of inflammatory activation and organ dysfunction in post-traumatic sepsis

Age/gender may likely influence the course of septic complications after trauma. We aimed to characterize the influence of age/gender on the response of circulating cytokines, cells and organ function in post-traumatic sepsis. We additionally tested whether post-traumatic responses alone can accurately predict outcomes in subsequent post-traumatic sepsis. A mouse 2-hit model of trauma/hemorrhage (TH, 1^st hit) and cecal ligation and puncture (CLP, 2^nd hit) was employed. 3, 15 and 20 month (m) old female (♀) and male (♂) CD-1 mice underwent sublethal TH followed by CLP 2 days later. Blood was sampled daily until day 6 post-TH and survival was followed for 16 days. To compare general response patterns among groups, we calculated two scores: the inflammatory response (including KC, MIP-1α, TNFα, MCP-1, IFNγ, IL-1β,-5,-6,-10) and the organ dysfunction score (Urea, ALT, AST and LDH). Moreover, mice were retrospectively divided into survivors (SUR) and dying (DIE) based on post-CLP outcome. In general, females survived better than males and their survival did not correspond to any specific estrus cycle phase. Pre-CLP phase: the post-TH inflammatory score was weakest in 3 m♂ but there were no changes among remaining groups (similar lack of differences in the organ dysfunction score). TH induced a 40% increase of IFNγ, MIP-1α and IL-5 in 15 m♂ SUR (vs. DIE) but predictive accuracy for post-CLP outcomes was moderate. Post-CLP phase: while stable in males, inflammatory response score in 15 m and 20 m females decreased with age at day 1 and 2 post-CLP. SUR vs. DIE differences in inflammatory and organ dysfunction score were evident but their magnitude was comparable across age/gender. Nearly identical activation of the humoral inflammatory and organ function compartments, both across groups and according to sepsis severity, suggests that they are not directly responsible for the age/gender-dependent disparity in TH-CLP survival in the studied young-to-mature population.

[Epidemiological profile of late mortality in severe polytraumatisms]

OBJECTIVE

A study is made of the epidemiology, chronogramand causes of late mortality in traumatized patients.

DESIGN

A prospective, observational cohort study of adult trauma patients was carried out.

SETTINGS

Province of Guipúzcoa (Basque Country, Spain). Intensive care unit of a tertiary hospital.

PATIENTS

Patients with severe trauma (Injury Severity Score > 15), admitted to the ICU from January 1995 to December 2009, with late death (> 7 days).

VARIABLES

Epidemiological, laboratory test, hemodynamic and transfusional data were collected. Severity scores: Abbreviated Injury Scale (AIS) and ISS.

RESULTS

Patients: 2003; ISS: 24.3±14.2. Total deaths: 405 (20%). Late mortality (>7 days): 102 (25.2%) patients, 9 years older and with a lower (18 points) ISS score than the patients who died early (48 hours). Most frequent injuries: AIS-Head-Cervical spine ≥ 4 (52%); AIS-Abdomen ≥ 4 (19.6%); AIS-Chest ≥ 4 (11.7%); AIS-Extremities ≥ 4 (4.9%). Causes of death: 1) brain death (14.7%); 2) multiorgan failure (67.6%), in two injury contexts: a) severe brain trauma in the vegetative state and high spinal cord injuries with tetraplegia (35.3%); and b) non-neurological injuries (32.3%) with a high prevalence of hypovolemic shock, multiple transfusion and coagulopathy; 3) miscellaneous (10.7%): post-resuscitation anoxic-ischemic encephalopathy, pulmonary embolism and massive stroke; 4) non-evaluable (7%).

CONCLUSIONS

Age, severity and type of injuries have an influence upon the time distribution and causality of late mortality. Brain death remains predominant, with multiorgan failure as the most frequent cause. This knowledge should contribute to the identification of problems, and to better organization of the structural and educational resources, thereby reducing the likely factors leading to death from trauma.

Acute management and outcome of multiple trauma patients with pelvic disruptions

INTRODUCTION

Data on prehospital and trauma-room fluid management of multiple trauma patients with pelvic disruptions are rarely reported. Present trauma algorithms recommend early hemorrhage control and massive fluid resuscitation. By matching the German Pelvic Injury Register (PIR) with the TraumaRegister DGU (TR) for the first time, we attempt to assess the initial fluid management for different Tile/OTA types of pelvic-ring fractures. Special attention was given to the patient's posttraumatic course, particularly intensive care unit (ICU) data and patient outcome.

METHODS

A specific match code was applied to identify certain patients with pelvic disruptions from both PIR and TR anonymous trauma databases, admitted between 2004 and 2009. From the resulting intersection set, a retrospective analysis was done of prehospital and trauma-room data, length of ICU stay, days of ventilation, incidence of multiple organ dysfunction syndrome (MODS), sepsis, and mortality.

RESULTS

In total, 402 patients were identified. Mean ISS was 25.9 points, and the mean of patients with ISS ≥ 16 was 85.6%. The fracture distribution was as follows: 19.7% type A, 29.4% type B, 36.6% type C, and 14.3% isolated acetabular and/or sacrum fractures. The type B/C, compared with type A fractures, were related to constantly worse vital signs that necessitated a higher volume of fluid and blood administration in the prehospital and/or the trauma-room setting. This group of B/C fractures were also related to a significantly higher presence of concomitant injuries and related to increased ISS. This was related to increased ventilation and ICU stay, increased rate of MODS, sepsis, and increased rate of mortality, at least for the type C fractures. Approximately 80% of the dead had sustained type B/C fractures.

CONCLUSIONS

The present study confirms the actuality of traditional trauma algorithms with initial massive fluid resuscitation in the recent therapy of multiple trauma patients with pelvic disruptions. Low-volume resuscitation seems not yet to be accepted in practice in managing this special patient entity. Mechanically unstable pelvic-ring fractures type B/C (according to the Tile/OTA classification) form a distinct entity that must be considered notably in future trauma algorithms.

Endogenous glucocorticoids promote the expansion of myeloid-derived suppressor cells in a murine model of trauma

Stress-dose of glucocorticoid has been demonstrated to be beneficial for trauma patients in clinical studies. Recently, a heterogeneous population of myeloid cells with immunosuppressive activity named myeloid-derived suppressor cells (MDSCs) has been found to accumulate in the trauma host and can be induced by glucocorticoids in vitro. In order to explore the effect of endogenous glucocorticoids on MDSCs under trauma conditions, we blocked the glucocorticoid signal in a murine trauma model using the antagonist of the glucocorticoid receptor RU486 (mifepristone). We found for the first time that RU486 not only blunted MDSC expansion induced by trauma in the spleen, peripheral blood and bone marrow especially at 6 h after traumatic stress but also decreased the survival rate from 100 to 20% in traumatic mice within 7 days. Moreover, neither MDSCs producing arginase-1 nor the morphological characterization of trauma-induced MDSCs was affected by the blockage of the glucocorticoid receptor. Our results suggest that endogenous glucocorticoids may promote MDSCs expansion in a murine trauma model and MDSCs may be beneficial for the trauma host.

Increased activation of the transcription factor c-Jun by MAP kinases in monocytes of multiple trauma patients is associated with adverse outcome and mass transfusion

BACKGROUND

Post-traumatic dysfunction of the immune system is a major source of morbidity and mortality in patients with multiple trauma. The underlying intracellular mechanisms are still incompletely understood. Previous mRNA expression studies in monocytes suggested an involvement of the MAP kinases p38 and JNK and of the transcription factor c-Jun. Therefore, it was the aim of this study to elucidate whether alterations in the protein expression p38 MAPK, JNK, and c-Jun could be linked to PRBC substitution and survival.

MATERIALS AND METHODS

Thirty-seven patients with blunt multiple injuries and an ISS > 16 points were enrolled in our study. Blood was drawn on admission and 6, 12, 24, 48, and 72 h after the traumatic event. Monocytes were isolated immediately after sample collection and nuclear protein was extracted and phosphoprotein concentrations were measured. The resulting data were statistically analyzed.

RESULTS

An increased activation of MAP kinases and c-Jun could be shown in patients who died from their injuries. Additionally, patients who received PRBC substitution ≥10 units exhibited increased expression of activated MAP kinases and c-Jun.

CONCLUSIONS

We present a serial, sequential investigation in human monocytes of major trauma patients evaluating the activation of p38 MAPK, JNK and c-Jun in the post-traumatic period. We show that death after trauma and massive PRBC substitution are associated with activation of this pathway. The p38 MAPK, JNK, and c-Jun have well established proinflammatory properties. Therefore, it appears likely that this pathway is involved in the systemic hyperinflammatory states seen after massive PRBC transfusion and multiple trauma.

Circulating leukotriene B4 identifies respiratory complications after trauma

Background. Leukotriene B4 (LTB4), a proinflammatory lipid mediator correlates well with the acute phase of Acute Respiratory Distress Syndrome (ARDS). Therefore, LTB4-levels were investigated to determine whether they might be a useful clinical marker in predicting pulmonary complications (PC) in multiply traumatized patients. Methods: Plasma levels of LTB4 were determined in 100 patients on admission (ED) and for five consecutive days (daily). Twenty healthy volunteers served as control. LTB4-levels were measured by ELISA. Thirty patients developed PC (pneumonia, respiratory failure, acute lung injury (ALI), ARDS, pulmonary embolism) and 70 had no PC (ØPC). Results. LTB4-levels in the PC-group [127.8 pg/mL, IQR: 104–200pg/ml] were significantly higher compared to the ØPC-group on admission [95.6 pg/mL, IQR: 55–143 pg/mL] or control-group [58.4 pg/mL, IQR: 36–108 pg/mL]. LTB4 continuously declined to basal levels from day 1 to 5 without differences between the groups. The cutoff to predict PC was calculated at 109.6 pg/mL (72% specificity, 67% sensitivity). LTB4 was not influenced by overall or chest injury severity, age, gender or massive transfusion. Patients with PC received mechanical ventilation for a significantly longer period of time, and had prolonged intensive care unit and overall hospital stay. Conclusion. High LTB4-levels indicate risk for PC development in multiply traumatized patients.

Systemic inflammatory effects of traumatic brain injury, femur fracture, and shock: an experimental murine polytrauma model

Objective. Despite broad research in neurotrauma and shock, little is known on systemic inflammatory effects of the clinically most relevant combined polytrauma. Experimental investigation in an animal model may provide relevant insight for therapeutic strategies. We describe the effects of a combined injury with respect to lymphocyte population and cytokine activation. Methods. 45 male C57BL/6J mice (mean weight 27 g) were anesthetized with ketamine/xylazine. Animals were subjected to a weight drop closed traumatic brain injury (WD-TBI), a femoral fracture and hemorrhagic shock (FX-SH). Animals were subdivided into WD-TBI, FX-SH and combined trauma (CO-TX) groups. Subjects were sacrificed at 96 h. Blood was analysed for cytokines and by flow cytometry for lymphocyte populations. Results. Mortality was 8%, 13% and 47% for FX-SH, WD-TBI and CO-TX groups (P < 0.05). TNFα (11/13/139 for FX-SH/WD-TBI/CO-TX; P < 0.05), CCL2 (78/96/227; P < 0.05) and IL-6 (16/48/281; P = 0.05) showed significant increases in the CO-TX group. Lymphocyte populations results for FX-SH, WD-TBI and CO-TX were: CD-4 (31/21/22; P = n.s.), CD-8 (7/28/34, P < 0.05), CD-4-CD-8 (11/12/18; P = n.s.), CD-56 (36/7/8; P < 0.05). Conclusion. This study shows that a combination of closed TBI and femur-fracture/ shock results in an increase of the humoral inflammation. More attention to combined injury models in inflammation research is indicated.