Epidemiology and risk factors of sepsis after multiple trauma: an analysis of 29,829 patients from the Trauma Registry of the German Society for Trauma Surgery

Epidemiology and risk factors of multiple-organ failure after multiple trauma: an analysis of 31,154 patients from the TraumaRegister DGU

BACKGROUND

In the severely injured who survive the early posttraumatic phase, multiple-organ failure (MOF) is the main cause of morbidity and mortality. An enhanced prediction of MOF might influence individual monitoring and therapy of severely injured patients.

METHODS

We performed a retrospective analysis of a nationwide prospective database, the TraumaRegister DGU of the German Trauma Society. Patients with complete data sets (2002-2011) and a relevant trauma load (Injury Severity Score [ISS] ≥ 16), who were admitted to an intensive care unit, were included.

RESULTS

Of a total of 31,154 patients enclosed in this study, 10,201 (32.7%) developed an MOF according to the Sequential Organ Failure Assessment score. During the study period, mortality of all patients decreased from 18.1% in 2002 to 15.3% in 2011 (p < 0.001). Meanwhile, MOF occurred significantly more often (24.6% in 2002 vs. 31.5% in 2011, p < 0.001), but mortality of MOF patients decreased (42.6% vs. 33.3%, p < 0.001). MOF patients who died survived 2 days less (11 days in 2002 vs. 8.9 days in 2011, p < 0.001). Independent risk factors for the development of MOF following severe trauma were age, ISS, head Abbreviated Injury Scale (AIS) score of 3 or higher, thoracic AIS score of 3 or higher, male sex, Glasgow Coma Scale (GCS) score of 8 or less, mass transfusion, base excess of less than -3, systolic blood pressure less than 90 mm Hg at admission, and coagulopathy.

CONCLUSION

Over one decade, we observed an ongoing decrease of mortality after multiple trauma, accompanied by decreasing mortality in the subgroup with MOF. However, incidence of MOF in the severely injured increased significantly. Thus, MOF after multiple trauma remains a challenge in intensive care. The risk factors from multivariate analysis could be instrumental in anticipating the early development of MOF. Furthermore, a reliable prediction model might be supportive for patient enrolment in trauma studies, in which MOF marks the primary end point.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

The burden of infection in severely injured trauma patients and the relationship with admission shock severity

BACKGROUND

Infection following severe injury is common and has a major impact on patient outcomes. The relationship between patient, injury, and physiologic characteristics with subsequent infections is not clearly defined. The objective of this study was to characterize the drivers and burden of all-cause infection in critical care trauma patients.

METHODS

A prospective cohort study of severely injured adult patients admitted to critical care was conducted. Data were collected prospectively on patient and injury characteristics, baseline physiology, coagulation profiles, and blood product use. Patients were followed up daily for infectious episodes and other adverse outcomes while in the hospital.

RESULTS

Three hundred patients (Injury Severity Score [ISS] >15) were recruited. In 48 hours or less, 29 patients (10%) died, leaving a cohort of 271. One hundred forty-one patients (52%) developed at least one infection. Three hundred four infections were diagnosed overall. Infection and noninfection groups were matched for age, sex, mechanism, and ISS. Infection rates were greater with any degree of admission shock and threefold higher in the most severely shocked cohort (p < 0.01). In multivariate analysis, base deficit (odds ratio [OR], 1.78, 95% confidence interval [CI], 1.48-1.94; p < 0.001) and lactate (OR, 1.36; 95% CI, 1.10-1.69; p = 0.05) were independently associated with the development of infection. Outcomes were significantly worse for the patients with infection. In multivariate logistic regression, infection was the only factor independently associated with multiple-organ failure (p < 0.001; OR, 15.4; 95% CI, 8.2-28.9; r = 0.402), ventilator-free days (p < 0.001; β, -4.48; 95% CI, -6.7 to -2.1; r = 0.245), critical care length of stay (p < 0.001; β, 13.2; 95% CI, 10.0-16.4; r = 0.466), and hospital length of stay (p < 0.001; β, 31.1; 95% CI, 24.0-38.2; r = 0.492).

CONCLUSION

Infectious complications are a burden for severely injured patients and occur early in the critical care stay. Severity of admission shock was predictive of infection and represents an opportunity for interventions to improve infectious outcomes. The incidence of infection may also have utility as an end point for clinical trials in trauma hemorrhage given the relationship with patient-experienced outcomes.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level II.

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.

Immune response to traumatic injury: harmony and discordance of immune system homeostasis

Trauma remains one of the leading causes of death worldwide. Traumatic injury disrupts immune system homeostasis and may predispose patients to opportunistic infections and inflammatory complications. Prevention of multiple organ dysfunction syndrome due to septic complications following severe trauma is a challenging problem. Following severe injury, the immune system usually tends toward a pro-inflammatory phenotype and then changes to a counter-inflammatory phenotype. This immune system homeostasis is believed to be a protective response based on the balance between the innate and adaptive immune systems. We reported that injury activates inflammasomes and primes Toll-like receptors. The primed innate immune system is prepared for a rapid and strong antimicrobial immune defense. However, trauma can also develop the "two-hit" response phenotype. We also reported that injury augments regulatory T cell activity, which can control the "two-hit" response phenotype in trauma. We discuss the current idea that traumatic injury induces a unique type of innate and adaptive immune response that may be triggered by damage-associated molecular pattern molecules, which are a combination of endogenous danger signal molecules that include alarmins and pathogen-associated molecular pattern molecules.

Toll-like receptor 1 polymorphisms and associated outcomes in sepsis after traumatic injury: a candidate gene association study

OBJECTIVE

To determine whether single nucleotide polymorphisms (SNPs) in TLR1 are associated with mortality, specifically sepsis-associated mortality, in a traumatically injured population.

BACKGROUND

Innate immune responses mediated by toll-like receptors (TLRs) induce early inflammatory responses to pathogen and damage-associated molecular patterns. Genetic variation in TLRs has been associated with susceptibility and outcomes in a number of infectious and noninfectious disease states.

METHODS

Patients admitted to the trauma intensive care unit at a level 1 trauma center serving 4 states were enrolled and followed for development of infection, sepsis, and death. Genomic DNA was genotyped and logistic regression analysis was performed to determine associations between TLR1 SNPs and mortality. We further examined for associations between TLR1 SNPs and mortality in subgroups on the basis of the presence of sepsis and the type of sepsis-associated organism.

RESULTS

We enrolled 1961 patients. TLR1-7202G (rs5743551) was associated with increased mortality after traumatic injury and this association was primarily observed in the subset of patients who developed sepsis [adjusted odds ratio (OR): 3.16; 95% confidence interval (CI): 1.43-6.97, P=0.004]. This association persisted after further restriction to gram-positive sepsis. TLR1(742A/G(Asn248Ser)) (rs4833095), a coding SNP in LD with TLR1-7202G, was also associated with mortality in gram-positive sepsis (adjusted OR: 4.16; 95% CI: 1.22-14.19, P=0.023).

CONCLUSIONS

Genetic variation in TLR1 is associated with increased mortality in patients with sepsis after traumatic injury and may represent a novel marker of risk for death in critically injured patients.

Biomarkers predicting sepsis in polytrauma patients: Current evidence

INTRODUCTION

Major trauma still represents one of the leading causes of death in the first four decades of life. Septic complications represent the predominant causes of late death (45% of overall mortality) in polytrauma patients. The ability of clinicians to early differentiate between systemic inflammatory response syndrome (SIRS) and sepsis is demonstrated to improve clinical outcome and mortality. The identification of an "ideal" biomarker able to early recognize incoming septic complications in trauma patients is still a challenge for researchers.

AIM

To evaluate the existing evidence regarding the role of biomarkers to predict or facilitate early diagnosis of sepsis in trauma patients, trying to compile some recommendations for the clinical setting.

METHODS

An Internet-based search of the MEDLINE, EMBASE and Cochrane Library databases was performed using the search terms: "Biomarkers", "Sepsis" and "Trauma" in various combinations. The methodological quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies Checklist (QUADAS). After data extraction, the level of evidence available for each bio-marker was rated and presented using the "best-evidence synthesis" method, in line with the US Agency for Healthcare Research and Quality.

RESULTS

Thirty studies were eligible for the final analysis: 13 case-control studies and 17 cohort studies. The "strong evidence" available demonstrated the potential use of procalcitonin as an early indicator of post-traumatic septic complications and reported the inability of c-reactive protein (CRP) to specifically identify infective complications. Moderate, conflicting and limited evidence are available for the other 31 biomarkers.

CONCLUSION

Several biomarkers have been evaluated for predicting or making early diagnosis of sepsis in trauma patients. Current evidence does not support the use of a single biomarker in diagnosing sepsis. However, procalcitonin trend was found to be useful in early identification of post-traumatic septic course and its use is suggested (Recommendation Grade: B) in clinical practice.

Pelvic trauma: What are the predictors of mortality and cardiac, venous thrombo-embolic and infectious complications following injury?

INTRODUCTION

This study sought to determine risk factors that influence mortality, cardiac events, venous thrombo-embolic disease (VTED), and infection following fractures of the pelvis and/or acetabulum.

METHODS

The 2008 National Sample Program (NSP) of the National Trauma Databank was queried to identify all patients who sustained pelvic and acetabular fractures. Demographic data, injury-specific and surgical characteristics, and medical co-morbidities were abstracted. The occurrence of in-hospital mortality, cardiac events, VTED and infections were documented. Univariate testing, weighted logistic regression, and sensitivity analyses were performed to identify significant independent predictors of mortality and the complications under study.

RESULTS

The NSP contained 41,297 cases of pelvic trauma. In-hospital mortality was documented in 3055 (7%) and one or more complications occurred in 6932 (17%). Cardiac events transpired in 2% of patients, VTED in 4% and infections in 3%. Increasing age, shock, time to procedure, ISS, and GCS were predictive of mortality. Cardiac events were found to be influenced by obesity, diabetes, ISS, GCS, age, and trauma mechanism. VTED was impacted by obesity, history of respiratory disease, male sex, ISS, GCS, medical co-morbidities, and time to procedure. Injuries caused by mechanisms other than blunt trauma, shock, age, ISS, GCS, medical co-morbidities, and time to procedure were associated with infection.

CONCLUSIONS

Several important predictors were identified for specific complications and mortality following pelvic trauma. The design of this study may render it more generalisable to American patients with pelvic injuries.

LEVEL OF EVIDENCE

II - Prognostic retrospective study of a prospective dataset.

Epidemiology of extremity injuries in multiple trauma patients

BACKGROUND

Previous studies have suggested that distinct extremity injuries are associated with worse outcome following major trauma. The aim of the present study was to determine epidemiological data of extremity injuries in multiple trauma patients with respect to prevalence, injury pattern, specific mechanisms of injury and their impact on mortality.

METHODS

The Trauma Register of the German Society for Trauma Surgery anonymously documents data on critically injured patients since 1993. Trauma cases documented between 2002 and 2009, older than 16 years of age and with an ISS ≥ 16 were divided into those with AIS ≥ 2 and those without a significant extremity injury. The groups were compared with respect to injury pattern, treatment characteristics and mortality.

RESULTS

More than half of the 24,885 patients (58.6%) had a significant extremity injury. On average patients with relevant extremity injuries sustained on average 2.1 fractures per case and 4.9% even sustained five or more extremity injuries. Fractures of the femur (16.5%), the tibia (12.6%) and the clavicle (10.4%) were the most common fractures. Patients without significant extremity injury had a significantly lower Glasgow Coma Scale at scene, a more severe brain injury and a higher 30-day- and in-hospital-mortality. In contrast, patients with significant extremity injuries had a higher rate of severe chest trauma, a higher rate of red cell blood transfusion as well a massive blood transfusion, more operative procedures and a longer ICU and in-hospital length of stay.

CONCLUSIONS

Multiple injured patients with and without significant extremity injuries can be regarded as two different populations with respect to early posttraumatic course and survival. Those without extremity injury had more severe head injuries and a higher mortality. However, significant extremity injury was associated with worse outcomes including a higher number of operative procedures, a higher rate of blood transfusion and a longer hospital length of stay.

The impact of anemia in moderate to severe traumatic brain injury

PURPOSE

The impact of anemia and restrictive transfusion strategies in traumatic brain injury (TBI) is unclear. The purpose of this study was to examine the outcome of varying degrees of anemia in patients who have sustained a TBI.

METHODS

We performed a retrospective study of all adult patients with isolated blunt TBI admitted between January 2003 and June 2010. The impact of increasing severity of anemia (Hb ≤8, ≤9, or ≤10 g/dl measured on three consecutive draws within the first 7 days of admission) and transfusions on complications, length of stay, and mortality was examined using univariate and multivariate analysis.

RESULTS

Of the 31,648 patients with blunt trauma admitted to the trauma service during the study period, 812 had an isolated TBI, among which 196 (24.1 %) met at least one of the anemia thresholds within the first 7 days [78 % male, mean age 47 ± 23 years, Injury Severity Score 16 ± 8, and head Abbreviated Injury Scale 3.3 ± 1.0]. Using a logistic regression model, anemia even as low as 8 g/dl was not associated with an increase in mortality [AOR8 = 0.8 (0.2, 3.2), p = 0.771; AOR9 = 0.8 (0.4, 1.6), p = 0.531; AOR10 = 0.6 (0.3, 1.3), p = 0.233] or complications. However, for all patients, the transfusion of packed red blood cells was associated with a significant increase in septic complications [AOR = 3.2 (1.5, 13.7), p = 0.030].

CONCLUSION

The presence of anemia in patients with TBI as low as 8 g/dl was not associated with increased mortality or complications, while the transfusion of red blood cells was associated with a significant increase in septic complications. Prospective evaluation of an optimal transfusion trigger in head-injured patients is warranted.

[New aspects of polytrauma treatment - current facts and developments: report of the first annual conference of the Committee on Emergency Medicine, Intensive Care and Trauma Management (Sektion NIS)]

Taking care of severely injured patients is a complex and ambitious mission. The committee on emergency medicine, intensive care and trauma management of the German Society of Trauma Surgery (Sektion NIS) has accepted this challenge. On the occasion of the release of the annual report of the TraumaRegistry DGU®, the committee held its first annual congress in order to provide members and an intrigued audience with current trends and results from the latest research in national trauma care ranging from the animal facility to the S3 guidelines. Topics of focus were new realizations based on data from the TraumaRegistry DGU® and means of quality assurance in trauma care. This article gives a report on the meeting and summarizes the major results of the presented studies and the latest deployments in this field of trauma research.

Predictors of sepsis in moderately severely injured patients: an analysis of the National Trauma Data Bank

BACKGROUND

Post-traumatic sepsis is a significant cause of in-hospital death. However, socio-demographic and clinical characteristics that may predict sepsis in injured patients are not well known. The objective of this study was to identify risk factors that may be associated with post-traumatic sepsis.

METHODS

Retrospective analysis of patients in the National Trauma Data Bank for 2007-2008. Patients older than 16 years of age with an Injury Severity Score (ISS) ≥ 9 points were included. Multivariable logistic regression was used to determine association of sepsis with patient (age, gender, ethnicity, and insurance status), injury (mechanism, ISS, injury type, hypotension), and clinical (major surgical procedure, intensive care unit admission) characteristics.

RESULTS

Of a total of 1.3 million patients, 373,370 met the study criteria, and 1.4% developed sepsis, with an associated mortality rate of approximately 20%. Age, male gender, African-American race, hypotension on emergency department presentation, and motor vehicle crash as the injury mechanism were independently associated with post-traumatic sepsis.

CONCLUSIONS

Socio-demographic and injury factors, such as age, race, hypotension on admission, and severity and mechanism of injury predict post-traumatic sepsis significantly. Further exploration to explain why these patient groups are at increased risk is warranted in order to understand better and potentially prevent this life-threatening complication.

What are predictors of mortality in patients with pelvic fractures?

BACKGROUND

Our knowledge of factors influencing mortality of patients with pelvic ring injuries and the impact of associated injuries is currently based on limited information.

QUESTIONS/PURPOSES

We identified the (1) causes and time of death, (2) demography, and (3) pattern and severity of injuries in patients with pelvic ring fractures who did not survive.

METHODS

We prospectively collected data on 5340 patients listed in the German Pelvic Trauma Registry between April 30, 2004 and July 29, 2011; 3034 of 5340 (57%) patients were female. Demographic data and parameters indicating the type and severity of injury were recorded for patients who died in hospital (nonsurvivors) and compared with data of patients who survived (survivors). The median followup was 13 days (range, 0-1117 days).

RESULTS

A total of 238 (4%) patients died a median of 2 days after trauma. The main cause of death was massive bleeding (34%), predominantly from the pelvic region (62% of all patients who died because of massive bleeding). Fifty-six percent of nonsurvivors and 43% of survivors were male. Nonsurvivors were characterized by a higher incidence of complex pelvic injuries (32% versus 8%), less isolated pelvic ring fractures (13% versus 49%), lower initial blood hemoglobin concentration (6.7 ± 2.9 versus 9.8 ± 3.0 g/dL) and systolic arterial blood pressure (77 ± 27 versus 106 ± 24 mmHg), and higher injury severity score (ISS) (35 ± 16 versus 15 ± 12).

CONCLUSION

Patients with pelvic fractures who did not survive were characterized by male gender, severe multiple trauma, and major hemorrhage.

LEVEL OF EVIDENCE

Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Comparison of mortality associated with sepsis in the burn, trauma, and general intensive care unit patient: a systematic review of the literature

The purpose of this systematic review of the literature was to determine the association of sepsis with mortality in the severely injured adult patient by means of a comparative analysis of sepsis in burn and trauma injury with other critically ill populations. The MEDLINE (PubMed), Cochrane Library, and ProQuest databases were searched. The following keywords and MeSH headings were used: "sepsis," septicemia," "septic shock," "epidemiology," "burns," "thermal injury," "trauma," "wounds and injuries," "critical care," "intensive care," "outcomes," and "mortality." Included studies were clinical studies of adult burn, trauma, and critically ill patients that reported survival data for sepsis. Thirty-eight articles were reviewed (9 burn, 11 trauma, 18 general critical care). The age of burn (<45 years) and trauma (34-49 years) groups was lower than the general critical care (57-64 years) population. Sepsis prevalence varied with trauma-injured patients experiencing fewer episodes (2.4%-16.9%) contrasted with burn patients (8%-42.5%) and critical care patients (19%-38%). Survival differed with trauma patients experiencing a lower rate of mortality associated with sepsis (7%-36.9%) compared with the burn (28%-65%) and critical care (21%-53%) groups. This study is the first to compare sepsis outcomes in three distinct patient populations: burn, trauma, and general critical care. Trauma patients tend to have relatively low sepsis-associated mortality; burn patients and the older critical care population have higher prevalence of sepsis with worse outcomes. Great variability of criteria to identify septic patients among studies compromises population comparisons.

Early interleukin-6 and slope of monocyte human leukocyte antigen-DR: a powerful association to predict the development of sepsis after major trauma

OBJECTIVE

Major trauma is characterized by a pro-inflammatory response, followed by an immunosuppression. Recently, in trauma patients, the lack of recovery of monocyte Human Leukocyte Antigen DR (mHLA-DR, a biomarker of ICU-acquired immunosuppression) between days 1-2 and days 3-4 has been demonstrated to be independently associated with sepsis development. The main objective of this study was to determine whether early measurements of IL-6 (interleukin-6) and IL-10 plasma concentrations (as markers of initial severity) could improve, in association with mHLA-DR recovery, the prediction of sepsis occurrence in severe trauma patients.

DESIGN

Prospective observational study over 24 months in a Trauma ICU at university hospital.

PATIENTS

Trauma patients with an ISS over 25 and age over 18 were included.

MEASUREMENTS AND MAIN RESULTS

mHLA-DR was assessed by flow cytometry, IL-6 and IL-10 concentrations by ELISA. 100 consecutive severely injured patients were monitored (mean ISS 37±10). 37 patients developed sepsis. IL-6 concentrations and slope of mHLA-DR expression between days 1-2 and days 3-4 were significantly different between septic and non-septic patients. IL-10 was not detectable in most patients. After adjustment for usual clinical confounders, when assessed as a pair, multivariate logistic regression analysis revealed that a slope of mHLA-DR expression (days 3-4/days 1-2)≤1.1 and a IL-6 concentration ≥ 67.1 pg/ml remained highly associated with the development of sepsis (adjusted OR 18.4, 95% CI 4.9; 69.4, p = .00002).

CONCLUSIONS

After multivariate regression logistic analysis, when assessed as a pair, a high IL-6 concentration and a persistent mHLA-DR decreased expression were found to be in relation with the development of sepsis with the best predictive value. This study underlines the usefulness of daily monitoring of immune function to identify trauma patients at a high risk of infection.

Synthetic molecules and functionalized nanoparticles targeting the LPS-TLR4 signaling: A new generation of immunotherapeutics

Toll-like receptor 4 (TLR4), the receptor of bacterial endotoxins in mammalians, plays a pivotal role in the induction of innate immunity and inflammation. TLR4 activation by bacterial lipopolysaccharide (LPS) is achieved by the coordinate and sequential action of three other proteins, the lipopolysaccharide binding protein (LBP), the cluster differentiation antigen CD14, and the myeloid differentiation protein (MD-2) receptors, that bind LPS and present it in a monomeric form to TLR4 by forming the activated [TLR4·MD-2·LPS]2 complex. Small molecules and nanoparticles active in modulating the TLR4 signal by targeting directly the MD-2·TLR4 complex or by interfering in other points of the TLR4 signaling are presented in this paper. These compounds have great pharmacological interest as vaccine adjuvants, immunotherapeutics, anti-sepsis, and anti-inflammatory agents.