Inflammation and the host response to injury, a large-scale collaborative project: patient-oriented research core--standard operating procedures for clinical care VII--Guidelines for antibiotic administration in severely injured patients

Technical and Medical Aspects of Burn Size Assessment and Documentation

In burn medicine, the percentage of the burned body surface area (TBSA-B) to the total body surface area (TBSA) is a crucial parameter to ensure adequate treatment and therapy. Inaccurate estimations of the burn extent can lead to wrong medical decisions resulting in considerable consequences for patients. These include, for instance, over-resuscitation, complications due to fluid aggregation from burn edema, or non-optimal distribution of patients. Due to the frequent inaccurate TBSA-B estimation in practice, objective methods allowing for precise assessments are required. Over time, various methods have been established whose development has been influenced by contemporary technical standards. This article provides an overview of the history of burn size estimation and describes existing methods with a critical view of their benefits and limitations. Traditional methods that are still of great practical relevance were developed from the middle of the 20th century. These include the "Lund Browder Chart", the "Rule of Nines", and the "Rule of Palms". These methods have in common that they assume specific values for different body parts' surface as a proportion of the TBSA. Due to the missing consideration of differences regarding sex, age, weight, height, and body shape, these methods have practical limitations. Due to intensive medical research, it has been possible to develop three-dimensional computer-based systems that consider patients' body characteristics and allow a very realistic burn size assessment. To ensure high-quality burn treatment, comprehensive documentation of the treatment process, and wound healing is essential. Although traditional paper-based documentation is still used in practice, it no longer meets modern requirements. Instead, adequate documentation is ensured by electronic documentation systems. An illustrative software already being used worldwide is "BurnCase 3D". It allows for an accurate burn size assessment and a complete medical documentation.

Sepsis and Critical Illness Research Center investigators: protocols and standard operating procedures for a prospective cohort study of sepsis in critically ill surgical patients

INTRODUCTION

Sepsis is a common, costly and morbid cause of critical illness in trauma and surgical patients. Ongoing advances in sepsis resuscitation and critical care support strategies have led to improved in-hospital mortality. However, these patients now survive to enter state of chronic critical illness (CCI), persistent low-grade organ dysfunction and poor long-term outcomes driven by the persistent inflammation, immunosuppression and catabolism syndrome (PICS). The Sepsis and Critical Illness Research Center (SCIRC) was created to provide a platform by which the prevalence and pathogenesis of CCI and PICS may be understood at a mechanistic level across multiple medical disciplines, leading to the development of novel management strategies and targeted therapies.

METHODS

Here, we describe the design, study cohort and standard operating procedures used in the prospective study of human sepsis at a level 1 trauma centre and tertiary care hospital providing care for over 2600 critically ill patients annually. These procedures include implementation of an automated sepsis surveillance initiative, augmentation of clinical decisions with a computerised sepsis protocol, strategies for direct exportation of quality-filtered data from the electronic medical record to a research database and robust long-term follow-up.

ETHICS AND DISSEMINATION

This study has been registered at ClinicalTrials.gov, approved by the University of Florida Institutional Review Board and is actively enrolling subjects. Dissemination of results is forthcoming.

Use of evidence-based recommendations in an antibiotic care bundle for the intensive care unit

PURPOSE

To drive decisions on antibiotic therapy in the intensive care unit (ICU), we developed an antibiotic care bundle (ABC-Bundle) with evidence-based recommendations (EBRs) for antibiotic prescriptions.

METHODS

We conducted a three-step prospective study. First, a systematic review was performed of the literature reporting EBRs for antibiotic usage in the ICU. Second, we developed an ABC-Bundle through a two-round, RAND-modified Delphi method with an international expert panel, including the most relevant EBRs on a 9-point Likert scale. Those EBRs that were considered mandatory by >50% of the experts were included in the bundle. Third, we assessed the adherence to and applicability of the bundle in two mixed university ICUs.

RESULTS

Out of 1190 potentially relevant articles, 14 (four guidelines, four randomised controlled trials and six systematic reviews) fulfilled the eligibility criteria. Six EBRs were classified as relevant: 1. Provide rationale for antibiotic start; 2. Perform appropriate microbiological sampling; 3. Prescribe empirical antibiotic therapy according to guidelines (Day 1); 4. Review diagnosis; 5. Evaluate de-escalation based on microbiological results (Days 2-5); and 6. Consider discontinuation of treatment (Days 3-5). Daily adherence to the ABC-Bundle, prospectively assessed in 861 days of therapy in 142 ICU patients, ranged from 2% to 37%.

CONCLUSION

The ABC-Bundle is a novel tool to improve delivery of appropriate antibiotic therapy to ICU patients. The low adherence in the prospective cohorts confirms the significant role that the ABC-Bundle could play in an antibiotic stewardship programme in the ICU setting.

An International Normalized Ratio-Based Definition of Acute Traumatic Coagulopathy Is Associated With Mortality, Venous Thromboembolism, and Multiple Organ Failure After Injury

OBJECTIVES

Acute traumatic coagulopathy is associated with adverse outcomes including death. Previous studies examining acute traumatic coagulopathy's relation with mortality are limited by inconsistent criteria for syndrome diagnosis, inadequate control of confounding, and single-center designs. In this study, we validated the admission international normalized ratio as an independent risk factor for death and other adverse outcomes after trauma and compared two common international normalized ratio-based definitions for acute traumatic coagulopathy.

DESIGN

Multicenter prospective observational study.

SETTING

Nine level I trauma centers in the United States.

PATIENTS

A total of 1,031 blunt trauma patients with hemorrhagic shock.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

International normalized ratio exhibited a positive adjusted association with all-cause in-hospital mortality, hemorrhagic shock-associated in-hospital mortality, venous thromboembolism, and multiple organ failure. Acute traumatic coagulopathy affected 50% of subjects if defined as an international normalized ratio greater than 1.2 and 21% of subjects if defined by international normalized ratio greater than 1.5. After adjustment for potential confounders, acute traumatic coagulopathy defined as an international normalized ratio greater than 1.5 was significantly associated with all-cause death (odds ratio [OR], 1.88; p < 0.001), hemorrhagic shock-associated death (OR, 2.44; p = 0.001), venous thromboembolism (OR, 1.73; p < 0.001), and multiple organ failure (OR, 1.38; p = 0.02). Acute traumatic coagulopathy defined as an international normalized ratio greater than 1.2 was not associated with an increased risk for the studied outcomes.

CONCLUSIONS

Elevated international normalized ratio on hospital admission is a risk factor for mortality and morbidity after severe trauma. Our results confirm this association in a prospectively assembled multicenter cohort of severely injured patients. Defining acute traumatic coagulopathy by using an international normalized ratio greater than 1.5 but not an international normalized ratio greater than 1.2 identified a clinically meaningful subset of trauma patients who, adjusting for confounding factors, experienced more adverse outcomes. Targeting future therapies for acute traumatic coagulopathy to patients with an international normalized ratio greater than 1.5 may yield greater returns than using a lower international normalized ratio threshold.

Traumatic injury, early gene expression, and gram-negative bacteremia

OBJECTIVES

Bacteremic trauma victims have a higher risk of death than their nonbacteremic counterparts. The role that altered immunity plays in the development of bacteremia is unknown. Using an existing dataset, we sought to determine if differences in early postinjury immune-related gene expression are associated with subsequent Gram-negative bacteremia.

DESIGN

Retrospective cohort study, a secondary analysis of the Glue Grant database.

SETTING

Seven level I trauma centers across the United State.

SUBJECTS

Severely injured blunt trauma patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Total leukocyte gene expression was compared between the subjects in whom Gram-negative bacteremia developed and those in whom it did not develop. We observed that Gram-negative bacteremia was an independent risk factor for death (odds ratio, 1.86; p = 0.015). We then compared gene expression at 12 and 96 hours after injury in 10 subjects in whom subsequently Gram-negative bacteremia developed matched to 26 subjects in whom it did not develop. At 12 hours, expression of 64 probes differed more than or equal to 1.5-fold; none represented genes related to innate or adaptive immunity. By 96 hours, 102 probes were differentially expressed with 20 representing 15 innate or adaptive immunity genes, including down-regulation of IL1B and up-regulation of IL1R2, reflecting suppression of innate immunity in Gram-negative bacteremia subjects. We also observed down-regulation of adaptive immune genes in the Gram-negative bacteremia subjects.

CONCLUSIONS

By 96 hours after injury, there are differences in leukocyte gene expression associated with the development of Gram-negative bacteremia, reflecting suppression of both innate and adaptive immunity. Gram-negative bacteremia after trauma is, in part, consequence of host immunity failure and may not be completely preventable by standard infection-control techniques.

Experience with an enteral-based nutritional support regimen in critically ill trauma patients

BACKGROUND

Assuring adequate enteral nutritional support in critically ill patients is challenging. By describing our experience, we sought to characterize the challenges, benefits, and complications of an approach that stresses enteral nutrition.

STUDY DESIGN

We examined nutritional support received by victims of blunt trauma from 8 trauma centers. We grouped patients according to mean daily enteral caloric intake during the first 7 days. Group 1 received the fewest (0 kcal/kg/d) and group 5 the greatest (16 to 30 kcal/kg/d) number of calories in the first week. We focused our analyses on the patients remaining in the ICU for 8 days or longer and compared clinical outcomes among the groups.

RESULTS

There were 1,100 patients in the ICU for 8 days or longer. Patients receiving the greatest number of enteral calories during the first week (group 5) had the highest incidence of ventilator-associated pneumonia (49%) and the lowest incidence of bacteremia (14%). Use of parenteral nutrition was associated with bacteremia (adjusted odds ratio = 2.5; 95% CI, 1.8-3.5), ventilator-associated pneumonia (adjusted odds ratio = 2.4; 95% CI, 1.7-3.3), and death (adjusted odds ratio = 1.9; 95% CI, 1.1-3.1).

CONCLUSIONS

Enteral caloric intake during the first week was related to the pattern and severity of injury and was associated with important infectious outcomes. Our observations support moderating enteral intake during the first week after injury and avoiding parenteral nutrition.

Comparing clinical predictors of deep venous thrombosis versus pulmonary embolus after severe injury: a new paradigm for posttraumatic venous thromboembolism?

BACKGROUND

The traditional paradigm is that deep venous thrombosis (DVT) and pulmonary embolus (PE) are different temporal phases of a single disease process, most often labeled as the composite end point venous thromboembolism (VTE). However, we theorize that after severe blunt injury, DVT and PE may represent independent thrombotic entities rather than different stages of a single pathophysiologic process and therefore exhibit different clinical risk factor profiles.

METHODS

We examined a large, multicenter prospective cohort of severely injured blunt trauma patients to compare clinical risk factors for DVT and PE, including indicators of injury severity, shock, resuscitation parameters, comorbidities, and VTE prophylaxis. Independent risk factors for each outcome were determined by cross-validated logistic regression modeling using advanced exhaustive model search procedures.

RESULTS

The study cohort consisted of 1,822 severely injured blunt trauma patients (median Injury Severity Score [ISS], 33; median base deficit, -9.5). Incidence of DVT and PE were 5.1% and 3.9%, respectively. Only 9 (5.7%) of 73 patients with a PE were also diagnosed with DVT. Independent risk factors associated with DVT include prophylaxis initiation within 48 hours (odds ratio [OR], 0.57; 95% confidence interval [CI], 0.36-0.90) and thoracic Abbreviated Injury Scale (AIS) score of 3 or greater (OR, 1.82; 95% CI, 1.12-2.95), while independent risk factors for PE were serum lactate of greater than 5 (OR, 2.33; 95% CI, 1.43-3.79) and male sex (OR, 2.12; 95% CI, 1.17-3.84). Both DVT and PE exhibited differing risk factor profiles from the classic composite end point of VTE.

CONCLUSION

DVT and PE exhibit differing risk factor profiles following severe injury. Clinical risk factors for diagnosis of DVT after severe blunt trauma include the inability to initiate prompt pharmacologic prophylaxis and severe thoracic injury, which may represent overall injury burden. In contrast, risk factors for PE are male sex and physiologic evidence of severe shock. We hypothesize that postinjury DVT and PE may represent a broad spectrum of pathologic thrombotic processes as opposed to the current conventional wisdom of peripheral thrombosis and subsequent embolus.

De-escalation of antimicrobial treatment for adults with sepsis, severe sepsis or septic shock

BACKGROUND

Mortality rates among patients with sepsis, severe sepsis or septic shock are highly variable throughout different regions or services and can be upwards of 50%. Empirical broad-spectrum antimicrobial treatment is aimed at achieving adequate antimicrobial therapy, thus reducing mortality; however, there is a risk that empirical broad-spectrum antimicrobial treatment can expose patients to overuse of antimicrobials. De-escalation has been proposed as a strategy to replace empirical broad-spectrum antimicrobial treatment by using a narrower antimicrobial therapy. This is done by reviewing the patient's microbial culture results and then making changes to the pharmacological agent or discontinuing a pharmacological combination.

OBJECTIVES

To evaluate the effectiveness and safety of de-escalation antimicrobial treatment for adult patients diagnosed with sepsis, severe sepsis or septic shock caused by any micro-organism.

SEARCH METHODS

In this updated version, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 10); MEDLINE via PubMed (from inception to October 2012); EMBASE (from inception to October 2012); LILACS (from inception to October 2012); Current Controlled Trials; bibliographic references of relevant studies; and specialists in the area. We applied no language restriction. We had previously searched the databases to August 2010.

SELECTION CRITERIA

We planned to include randomized controlled trials (RCTs) comparing de-escalation (based on culture results) versus standard therapy for adults with sepsis, severe sepsis or septic shock. The primary outcome was mortality (at 28 days, hospital discharge or at the end of the follow-up period). Studies including patients initially treated with an empirical but not adequate antimicrobial therapy were not considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors planned to independently select and extract data and to evaluate methodological quality of all studies. We planned to use relative risk (risk ratio) for dichotomous data and mean difference (MD) for continuous data, with 95% confidence intervals. We planned to use the random-effects statistical model when the estimate effects of two or more studies could be combined in a meta-analysis.

MAIN RESULTS

Our search strategy retrieved 493 studies. No published RCTs testing de-escalation of antimicrobial treatment for adult patients diagnosed with sepsis, severe sepsis or septic were included in this review. We found one ongoing RCT.

AUTHORS' CONCLUSIONS

There is no adequate, direct evidence as to whether de-escalation of antimicrobial agents is effective and safe for adults with sepsis, severe sepsis or septic shock. This uncertainty warrants further research via RCTs and the authors are awaiting the results of an ongoing RCT testing the de-escalation of empirical antimicrobial therapy for severe sepsis.

Acute respiratory distress syndrome after trauma: development and validation of a predictive model

OBJECTIVE

To determine early clinical predictors of acute respiratory distress syndrome after major traumatic injury and characterize the performance of this acute respiratory distress syndrome prediction model, and two previously published acute respiratory distress syndrome prediction models, in an independent cohort of severely injured patients.

DESIGN

Prospective cohort study.

SETTING

University-affiliated level I trauma center in Seattle, WA, and nine hospitals participating in the Inflammation and Host Response to Injury Consortium.

PATIENTS

Model derivation utilized data from 224 patients participating in a randomized controlled trial. All models were validated in an independent cohort of 1,762 trauma patients.

MEASUREMENTS AND MAIN RESULTS

Variables strongly associated with acute respiratory distress syndrome in bivariate analysis (p<.01) were entered into a multiple logistic regression equation to generate an acute respiratory distress syndrome predictive model. We evaluated the performance of all models using the area under the receiver operator characteristic curve. Acute respiratory distress syndrome occurred in 79 subjects (35%) belonging to the development cohort and in 423 subjects (24%) from the validation cohort. Multivariable predictors of acute respiratory distress syndrome after trauma included subject age, Acute Physiology and Chronic Health Evaluation II Score, injury severity score, and the presence of blunt traumatic injury, pulmonary contusion, massive transfusion, and flail chest injury (area under the receiver operator characteristic curve 0.79 [95% confidence interval 0.73, 0.85]). Validation of the prediction model resulted in an area under the receiver operator characteristic curve of 0.71 (95% confidence interval 0.68, 0.74). Our model's performance in the validation cohort was superior to that of two other published acute respiratory distress syndrome prediction models (0.65 [95% confidence interval 0.63, 0.68] and 0.66 [95% confidence interval 0.64, 0.69], p<.01 for all comparisons).

CONCLUSIONS

Using routinely available clinical data, our prediction model identifies patients at high risk for acute respiratory distress syndrome early after severe traumatic injury. This predictive model could facilitate enrollment of subjects into future clinical trials designed to prevent this serious complication.

The changing pattern and implications of multiple organ failure after blunt injury with hemorrhagic shock

OBJECTIVES

To describe the incidence of postinjury multiple organ failure and its relationship to nosocomial infection and mortality in trauma centers using evidence-based standard operating procedures.

DESIGN

Prospective cohort study wherein standard operating procedures were developed and implemented to optimize postinjury care.

SETTING

Seven U.S. level I trauma centers.

PATIENTS

Severely injured patients (older than age 16 yrs) with a blunt mechanism, systolic hypotension (<90 mm Hg), and/or base deficit (≥6 mEq/L), need for blood transfusion within the first 12 hrs, and an abbreviated injury score ≥2 excluding brain injury were eligible for inclusion.

MEASUREMENTS AND MAIN RESULTS

One thousand two patients were enrolled and 916 met inclusion criteria. Daily markers of organ dysfunction were prospectively recorded for all patients while receiving intensive care. Overall, 29% of patients had multiple organ failure develop. Development of multiple organ failure was early (median time, 2 days), short-lived, and predicted an increased incidence of nosocomial infection, whereas persistence of multiple organ failure predicted mortality. However, surprisingly, nosocomial infection did not increase subsequent multiple organ failure and there was no evidence of a "second-hit"-induced late-onset multiple organ failure.

CONCLUSIONS

Multiple organ failure remains common after severe injury. Contrary to current paradigms, the onset is only early, and not bimodal, nor is it associated with a "second-hit"-induced late onset. Multiple organ failure is associated with subsequent nosocomial infection and increased mortality. Standard operating procedure-driven interventions may be associated with a decrease in late multiple organ failure and morbidity.

Benchmarking outcomes in the critically injured trauma patient and the effect of implementing standard operating procedures

OBJECTIVE

To determine and compare outcomes with accepted benchmarks in trauma care at 7 academic level I trauma centers in which patients were treated on the basis of a series of standard operating procedures (SOPs).

BACKGROUND

Injury remains the leading cause of death for those younger than 45 years. This study describes the baseline patient characteristics and well-defined outcomes of persons hospitalized in the United States for severe blunt trauma.

METHODS

We followed 1637 trauma patients from 2003 to 2009 up to 28 hospital days using SOPs developed at the onset of the study. An extensive database on patient and injury characteristics, clinical treatment, and outcomes was created. These data were compared with existing trauma benchmarks.

RESULTS

The study patients were critically injured and were in shock. SOP compliance improved 10% to 40% during the study period. Multiple organ failure and mortality rates were 34.8% and 16.7%, respectively. Time to recovery, defined as the time until the patient was free of organ failure for at least 2 consecutive days, was developed as a new outcome measure. There was a reduction in mortality rate in the cohort during the study that cannot be explained by changes in the patient population.

CONCLUSIONS

This study provides the current benchmark and the overall positive effect of implementing SOPs for severely injured patients. Over the course of the study, there were improvements in morbidity and mortality rates and increasing compliance with SOPs. Mortality was surprisingly low, given the degree of injury, and improved over the duration of the study, which correlated with improved SOP compliance.

Relationship between feeding tube site and respiratory outcomes

BACKGROUND

It is unclear if placing feeding tubes postpylorically to prevent respiratory complications is worth the extra effort. This study sought to determine the extent to which aspiration and pneumonia are associated with feeding site (controlling for the effects of severity of illness, degree of head-of-bed elevation, level of sedation, and use of gastric suction).

METHODS

A retrospective analysis was performed on a large data set gathered prospectively to evaluate aspiration in critically ill, mechanically ventilated patients. Feeding site was designated by attending physicians and confirmed by radiography. Each patient participated in the study for 3 consecutive days, with pneumonia assessed by the simplified Clinical Pulmonary Infection Score on the fourth day. Tracheal secretions were assayed for pepsin in a research laboratory; the presence of pepsin served as a proxy for aspiration. A total of 428 patients were included in the regression analyses performed to address the research objectives.

RESULTS

As compared with the stomach, the percentage of aspiration was 11.6% lower when feeding tubes were in the first portion of the duodenum, 13.2% lower when in the second/third portions of the duodenum, and 18.0% lower when in the fourth portion of the duodenum and beyond (all significant at P < .001). Pneumonia occurred less often when feedings were introduced at or beyond the second portion of the duodenum (P = .020).

CONCLUSIONS

The findings support feeding critically ill patients with numerous risk factors for aspiration in the mid-duodenum and beyond to reduce the risk of aspiration and associated pneumonia.

A genomic storm in critically injured humans

Critical injury in humans induces a genomic storm with simultaneous changes in expression of innate and adaptive immunity genes.

Human survival from injury requires an appropriate inflammatory and immune response. We describe the circulating leukocyte transcriptome after severe trauma and burn injury, as well as in healthy subjects receiving low-dose bacterial endotoxin, and show that these severe stresses produce a global reprioritization affecting >80% of the cellular functions and pathways, a truly unexpected “genomic storm.” In severe blunt trauma, the early leukocyte genomic response is consistent with simultaneously increased expression of genes involved in the systemic inflammatory, innate immune, and compensatory antiinflammatory responses, as well as in the suppression of genes involved in adaptive immunity. Furthermore, complications like nosocomial infections and organ failure are not associated with any genomic evidence of a second hit and differ only in the magnitude and duration of this genomic reprioritization. The similarities in gene expression patterns between different injuries reveal an apparently fundamental human response to severe inflammatory stress, with genomic signatures that are surprisingly far more common than different. Based on these transcriptional data, we propose a new paradigm for the human immunological response to severe injury.

The Glue Grant experience: characterizing the post injury genomic response

Despite ongoing improvements in resuscitation, care, and outcomes, traumatic injury remains a significant health care and economic burden. The causes are multifactorial, but our approach to the clinical management of these patients remains limited by our current understanding of the pathobiology of the disease. A multicenter, multidisciplinary program known as the "Inflammation and the Host Response to Injury" Large Scale Collaborative Research Program was created by the National Institute of General Medical Sciences (NIGMS, U54 GM062119-10) in 2001 in a 10-year effort to address some of these issues. Its primary goal is to describe the human genomic response to severe trauma and burns, and to examine changes in gene expression in the context of different clinical outcomes. The Program has not only successfully implemented clinical care guidelines for managing the severe trauma patient based on the best available evidence to minimize iatrogenic variability, but it has also examined the genome-wide, immune-inflammatory response in total and isolated blood leukocyte populations. This review will address current milestones as well as future directions for the Program.

Early elevation in random plasma IL-6 after severe injury is associated with development of organ failure

Excessive proinflammatory activation after trauma plays a role in late morbidity and mortality, including the development of multiple organ dysfunction syndrome (MODS). To date, identification of patients at risk has been challenging. Results from animal and human studies suggest that circulating interleukin 6 (IL-6) may serve as a biomarker for excessive inflammation. The purpose of this analysis was to determine the association of IL-6 with outcome in a multicenter developmental cohort and in a single-center validation cohort. Severely injured patients with shock caused by hemorrhage were evaluated within a multicenter developmental cohort (n = 79). All had blood drawn within 12 h of injury. Plasma IL-6 was determined by multiplex proteomic analysis. Clinical and outcome data were prospectively obtained. Within this developmental cohort, a plasma IL-6 level was determined for the subsequent development of MODS by developing a receiver operating curve and defining the optimal IL-6 level using the Youden Index. This IL-6 level was then evaluated within a separate validation cohort (n = 56). A receiver operating curve was generated for IL-6 and MODS development, with an IL-6 level of 350 pg/mL having the highest sensitivity and specificity within the developmental cohort. IL-6 was associated with MODS after adjusting for Acute Physiology and Chronic Health Evaluation, Injury Severity Score, male sex, and blood transfusions with an odds ratio of 3.9 (95% confidence interval, 1.33 - 11.19). An IL-6 level greater than 350 pg/mL within the validation cohort was associated with an increase in MODS score, MODS development, ventilator days, intensive care unit length of stay, and hospital length of stay. However, this IL-6 level was not associated with either the development of nosocomial infection or mortality. Elevation in plasma IL-6 seems to correlate with a poor prognosis. This measurement may be useful as a biomarker for prognosis and serve to identify patients at higher risk of adverse outcome that would benefit from novel therapeutic interventions.

Early elevation in random plasma IL-6 after severe injury is associated with development of organ failure

Excessive proinflammatory activation after trauma plays a role in late morbidity and mortality, including the development of multiple organ dysfunction syndrome (MODS). To date, identification of patients at risk has been challenging. Results from animal and human studies suggest that circulating interleukin 6 (IL-6) may serve as a biomarker for excessive inflammation. The purpose of this analysis was to determine the association of IL-6 with outcome in a multicenter developmental cohort and in a single-center validation cohort. Severely injured patients with shock caused by hemorrhage were evaluated within a multicenter developmental cohort (n = 79). All had blood drawn within 12 h of injury. Plasma IL-6 was determined by multiplex proteomic analysis. Clinical and outcome data were prospectively obtained. Within this developmental cohort, a plasma IL-6 level was determined for the subsequent development of MODS by developing a receiver operating curve and defining the optimal IL-6 level using the Youden Index. This IL-6 level was then evaluated within a separate validation cohort (n = 56). A receiver operating curve was generated for IL-6 and MODS development, with an IL-6 level of 350 pg/mL having the highest sensitivity and specificity within the developmental cohort. IL-6 was associated with MODS after adjusting for Acute Physiology and Chronic Health Evaluation, Injury Severity Score, male sex, and blood transfusions with an odds ratio of 3.9 (95% confidence interval, 1.33 - 11.19). An IL-6 level greater than 350 pg/mL within the validation cohort was associated with an increase in MODS score, MODS development, ventilator days, intensive care unit length of stay, and hospital length of stay. However, this IL-6 level was not associated with either the development of nosocomial infection or mortality. Elevation in plasma IL-6 seems to correlate with a poor prognosis. This measurement may be useful as a biomarker for prognosis and serve to identify patients at higher risk of adverse outcome that would benefit from novel therapeutic interventions.

De-escalation of antimicrobial treatment for adults with sepsis, severe sepsis or septic shock

BACKGROUND

Mortality rates among patients with sepsis, severe sepsis or septic shock ranges from 27% to 54%. Empirical broad-spectrum antimicrobial treatment is aimed at achieving adequate antimicrobial therapy and thus reducing mortality. However, there is a risk that empirical broad-spectrum antimicrobial treatment can expose patients to overuse of antimicrobials. De-escalation has been proposed as a strategy to replace empirical broad-spectrum antimicrobial treatment with a narrower antimicrobial therapy. This is done by either changing the pharmacological agent or discontinuing a pharmacological combination according to the patient's microbial culture results.

OBJECTIVES

To evaluate the effectiveness and safety of de-escalation antimicrobial treatment for adult patients diagnosed with sepsis, severe sepsis or septic shock caused by any micro-organism.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 8); MEDLINE via PubMed (from inception to August 2010); EMBASE (from inception to August 2010); LILACS (from inception to August 2010); Current Controlled Trials and bibliographic references of relevant studies. We also contacted the main authors in the area. We applied no language restriction.

SELECTION CRITERIA

We planned to include randomized controlled trials comparing de-escalation (based on culture results) versus standard therapy for adults with sepsis, severe sepsis or septic shock. The primary outcome was mortality (at 28 days, hospital discharge or the end of the follow-up period). Studies including patients initially treated with an empirical but not adequate antimicrobial therapy were not considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors planned to independently select and extract data and evaluate methodological quality of all studies. We planned to use relative risk (risk ratio) for dichotomous data and mean difference (MD) for continuous data, with 95% confidence intervals. We planned to use the random-effects statistical model when the estimate effects of two or more studies could be combined in a meta-analysis.

MAIN RESULTS

We retrieved 436 references via the search strategy. No randomized controlled trials testing de-escalation antimicrobial treatment for adult patients diagnosed with sepsis, severe sepsis or septic shock could be included in this review.

AUTHORS' CONCLUSIONS

There is no adequate, direct evidence as to whether de-escalation of antimicrobial agents is effective and safe for adults with sepsis, severe sepsis or septic shock. Therefore, it is not possible to either recommend or not recommend the de-escalation of antimicrobial agents in clinical practice for septic patients. This uncertainty warrants further research via randomized controlled trials or cohort studies.

Bench-to-bedside review: Burn-induced cerebral inflammation--a neglected entity?

Severe burn injury remains a major burden on patients and healthcare systems. Following severe burns, the injured tissues mount a local inflammatory response aiming to restore homeostasis. With excessive burn load, the immune response becomes disproportionate and patients may develop an overshooting systemic inflammatory response, compromising multiple physiological barriers in the lung, kidney, liver, and brain. If the blood–brain barrier is breached, systemic inflammatory molecules and phagocytes readily enter the brain and activate sessile cells of the central nervous system. Copious amounts of reactive oxygen species, reactive nitrogen species, proteases, cytokines/chemokines, and complement proteins are being released by these inflammatory cells, resulting in additional neuronal damage and life-threatening cerebral edema. Despite the correlation between cerebral complications in severe burn victims with mortality, burn-induced neuroinflammation continues to fly under the radar as an underestimated entity in the critically ill burn patient. In this paper, we illustrate the molecular events leading to blood–brain barrier breakdown, with a focus on the subsequent neuroinflammatory changes leading to cerebral edema in patients with severe burns.