New strategies for clinical trials in patients with sepsis and septic shock

Association Between Lack of Blinding and Mortality Results in Critical Care Randomized Controlled Trials: A Meta-Epidemiological Study

OBJECTIVES

To investigate whether intervention effect estimates for mortality differ between blinded and nonblinded randomized controlled trials conducted in critical care. We used a meta-epidemiological approach, comparing effect estimates between blinded and nonblinded randomized controlled trials for the same research question.

DATA SOURCES

Systematic reviews and meta-analyses of randomized controlled trials evaluating a therapeutic intervention on mortality in critical care, published between January 2009 and March 2019 in high impact factor general medical or critical care journals and by Cochrane.

DATA EXTRACTION

For each randomized controlled trial included in eligible meta-analyses, we evaluated whether the trial was blinded (i.e., double-blinded and/or reporting adequate methods) or not (i.e., open-label, single-blinded, or unclear). We collected risk of bias evaluated by the review authors and extracted trial results.

DATA SYNTHESIS

Within each meta-analysis, we compared intervention effect estimates between blinded and nonblinded randomized controlled trials by using a ratio of odds ratio (< 1 indicates larger estimates in nonblinded than blinded randomized controlled trials). We then combined ratio of odds ratios across meta-analyses to obtain the average relative difference between nonblinded and blinded trials. Among 467 randomized controlled trials included in 36 meta-analyses, 267 (57%) were considered blinded and 200 (43%) nonblinded. Intervention effect estimates were statistically significantly larger in nonblinded than blinded trials (combined ratio of odds ratio, 0.91; 95% CI, 0.84-0.99). We found no heterogeneity across meta-analyses (p = 0.72; I2 = 0%; τ2 = 0). Sensitivity analyses adjusting the main analysis on risk of bias items yielded consistent results.

CONCLUSIONS

Intervention effect estimates of mortality were slightly larger in nonblinded than blinded randomized controlled trials conducted in critical care, but confounding cannot be excluded. Blinding of both patients and personnel is important to consider when possible in critical care trials, even when evaluating mortality.

Which Biomarkers Can Be Used as Diagnostic Tools for Infection in Suspected Sepsis?

The diagnosis of infection in patients with suspected sepsis is frequently difficult to achieve with a reasonable degree of certainty. Currently, the diagnosis of infection still relies on a combination of systemic manifestations, manifestations of organ dysfunction, and microbiological documentation. In addition, the microbiologic confirmation of infection is obtained only after 2 to 3 days of empiric antibiotic therapy. These criteria are far from perfect being at least in part responsible for the overuse and misuse of antibiotics, in the community and in hospital, and probably the main drive for antibiotic resistance. Biomarkers have been studied and used in several clinical settings as surrogate markers of infection to improve their diagnostic accuracy as well as in the assessment of response to antibiotics and in antibiotic stewardship programs. The aim of this review is to provide a clear overview of the current evidence of usefulness of biomarkers in several clinical scenarios, namely, to diagnose infection to prescribe antibiotics, to exclude infection to withhold antibiotics, and to identify the causative pathogen to target antimicrobial treatment. In recent years, new evidence with "old" biomarkers, like C-reactive protein and procalcitonin, as well as new biomarkers and molecular tests, as breathomics or bacterial DNA identification by polymerase chain reaction, increased markedly in different areas adding useful information for clinical decision making at the bedside when adequately used. The recent evidence shows that the information given by biomarkers can support the suspicion of infection and pathogen identification but also, and not less important, can exclude its diagnosis. Although the ideal biomarker has not yet been found, there are various promising biomarkers that represent true evolutions in the diagnosis of infection in patients with suspected sepsis.

Reporting of Organ Support Outcomes in Septic Shock Randomized Controlled Trials: A Methodologic Review-The Sepsis Organ Support Study

OBJECTIVES

Many recent randomized controlled trials in the field of septic shock failed to demonstrate a benefit on mortality. Randomized controlled trials increasingly report organ support duration and organ support-free days as primary or secondary outcomes. We conducted a methodologic systematic review to assess how organ support outcomes were defined and reported in septic shock randomized controlled trials.

DATA SOURCES

MEDLINE via PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science.

STUDY SELECTION

We included randomized controlled trials published between January 2004 and March 2018 that involved septic shock adults and assessed organ support duration and/or organ support-free days for hemodynamic support, respiratory support, or renal replacement therapy.

DATA EXTRACTION

For each randomized controlled trial, we extracted the definitions of organ support duration and organ support-free days. We particularly evaluated how nonsurvivors were accounted for. Study authors were contacted to provide any missing information regarding these definitions.

DATA SYNTHESIS

We included 28 randomized controlled trials. Organ support duration and organ support-free days outcomes were reported in 17 and 15 randomized controlled trials, respectively, for hemodynamic support, 15 and 15 for respiratory support, and five and nine for renal replacement therapy. Nonsurvivors were included in the organ support duration calculation in 13 of 14 randomized controlled trials (93%) for hemodynamic support and nine of 10 (90%) for respiratory support. The organ support-free days definition for hemodynamic support, respiratory support, and renal replacement therapy was reported in six of 15 randomized controlled trials (40%), eight of 15 randomized controlled trials (53%), and six of nine randomized controlled trials (67%) reporting an organ support-free days outcome, respectively. Of these, one half assigned "0" to nonsurvivors, and the other half attributed one point per day alive free of organ support up to a predefined time point.

CONCLUSIONS

This study highlights the heterogeneity and infrequency of organ support duration/organ support-free days outcome reporting in septic shock trials. When reported, the definitions of these outcome measures and methods of calculation are also infrequently reported, in particular how nonsurvivors were accounted for, which may have an important impact on interpretation.

Maximum Likelihood Estimation in a Semicontinuous Survival Model with Covariates Subject to Detection Limits

Semicontinuous data are common in biological studies, occurring when a variable is continuous over a region but has a point mass at one or more points. In the motivating Genetic and Inflammatory Markers of Sepsis (GenIMS) study, it was of interest to determine how several biomarkers subject to detection limits were related to survival for patients entering the hospital with community acquired pneumonia. While survival times were recorded for all individuals in the study, the primary endpoint of interest was the binary event of 90-day survival, and no patients were lost to follow-up prior to 90 days. In order to use all of the available survival information, we propose a two-part regression model where the probability of surviving to 90 days is modeled using logistic regression and the survival distribution for those experiencing the event prior to this time is modeled with a truncated accelerated failure time model. We assume a series of mixture of normal regression models to model the joint distribution of the censored biomarkers. To estimate the parameters in this model, we suggest a Monte Carlo EM algorithm where multiple imputations are generated for the censored covariates in order to estimate the expectation in the E-step and then weighted maximization is applied to the observed and imputed data in the M-step. We conduct simulations to assess the proposed model and maximization method, and we analyze the GenIMS data set.

Pelargonidin Protects Against Renal Injury in a Mouse Model of Sepsis

Pelargonidin (PEL) is a well-known red pigment found in plants, and it has been reported to have important biological activities that are potentially beneficial for human health. This study was initiated to determine whether PEL could modulate renal functional damage in a mouse model of sepsis, and to elucidate the underlying mechanisms. The potential of PEL treatment to reduce renal damage induced by cecal ligation and puncture (CLP) surgery in mice was measured by assessment of serum creatinine, blood urea nitrogen (BUN), lipid peroxidation, total glutathione, glutathione peroxidase (GSH-Px) activity, catalase activity, and superoxide dismutase (SOD) activity. Treatment with PEL resulted in elevated plasma levels of BUN and creatinine, and of protein in urine in mice with CLP-induced renal damage. Moreover, PEL inhibited nuclear factor-κB activation and reduced the induction of nitric oxide synthase and excessive production of nitric acid. PEL treatment also reduced the plasma levels of interleukin-6 and tumor necrosis factor-α reduced lethality due to CLP-induced sepsis, increased lipid peroxidation, and markedly enhanced the antioxidant defense system by restoring the levels of SOD, GSH-Px, and catalase in kidney tissues. These results suggested that PEL protects mice against sepsis-triggered renal injury.

The Modulatory Effect of Lead Drug Candidates on Inflammatory Gene Expression in Sepsis: A Mini-Review

Sepsis is a debilitating clinical syndrome of systemic inflammation in response to microorganisms especially Gram-positive and Gram-negative bacteria. A minority of sepsis cases could be due to non-pathogenic insult such as trauma. Much of the tissue and organ injury observed among septic patients is a consequence of the inflammatory response. The search for effective treatments of sepsis has led to several studies by different research groups across the globe. Although many targets and molecules have been identified, there is still no effective treatment for sepsis. The aim of this report is to review the literature on drugs and drug candidates against sepsis and how they modulate the expression of inflammatory genes. Many compounds have been identified to regulate inflammatory gene expression by interacting with targets such as topoisomerase 1 and nuclear factor kappa B, which regulate the production of pro- and anti-inflammatory cytokines. Even though these compounds appear promising as potential drugs against sepsis, no effective therapies have been discovered to date and thus the fight against sepsis continues.

The prognostic value of brain natriuretic peptide (BNP) in non-cardiac patients with sepsis, ultra-long follow-up

OBJECTIVES

Sepsis is a multifactorial syndrome with increasing incidence of morbidity and mortality. Identification of outcome predictors is therefore essential. Recently, elevated brain natriuretic peptide (BNP) levels have been observed in patients with septic shock. Little information is available concerning BNP levels in patients with critical illness, especially with sepsis. Therefore, this study aims to evaluate the role of BNP as a biomarker for long-term mortality in patients with sepsis.

METHODS

We studied 259 patients with sepsis and absence of heart failure. BNP levels were obtained for all patients. A long-term survival follow-up was done, and survival was evaluated 90days after admission, and during the subsequent 60months of follow-up.

RESULTS

Eighty-two patients died during the 90-day follow-up (31.7%), 53 died in the index hospitalization (20.5%). On multivariate analysis models, elevated values of BNP were a strong predictor of in-hospital mortality, 90-day and 60-month mortality in patients with sepsis. BNP was a better prognostic predictor than the Sepsis-related Organ Failure Assessment (SOFA) score for 90-day mortality, and a better predictor for 60-month mortality in low risk groups.

CONCLUSION

In the population of hospitalized patients with sepsis, BNP is a strong independent predictor of short- and long-term mortality.

Cudratricusxanthone A attenuates renal injury in septic mice

As a natural compound extracted from the roots of Cudrania tricuspidata Bureau, Cudratricusxanthone A (CTXA) is known to possess hepatoprotective, anti-inflammatory, and anti-proliferative activities. This study was aimed to clarify the role of CTXA in modulating renal functional damage in a mouse model of sepsis and to elucidate its underlying mechanisms. We examined the renal protective effects of CTXA on cecal ligation and puncture (CLP)-induced renal damage by assessment of serum creatinine, blood urea nitrogen (BUN), lipid peroxidation, total glutathione, glutathione peroxidase activity, catalase activity, and superoxide dismutase activity. Post-treatment with CTXA resulted in a significant reduction in the deleterious renal functions by CLP, such as elevated BUN, creatinine, and urine protein. Induction of nitric oxide synthase and excessive production of nitric acid by CLP surgery were significantly reduced by post-treatment with CTXA via inhibiting nuclear factor-κB activation. Furthermore, the plasma levels of interleukin-6 and tumor necrosis factor-α were suppressed by CTXA post-treatment. Concurrently, CTXA treatment potently suppressed the CLP-induced septic lethality, rise of lipid peroxidation and markedly enhanced the antioxidant defense system by restoring the levels of superoxide dismutase, glutathione peroxidase, and catalase in kidney. The present results suggested that CTXA could protect against sepsis-triggered renal injury in mice.

Brief Report: Clinical Trials Aiming to Prevent Rheumatoid Arthritis Cannot Detect Prevention Without Adequate Risk Stratification: A Trial of Methotrexate Versus Placebo in Undifferentiated Arthritis as an Example

OBJECTIVE

Prevention of rheumatoid arthritis (RA) was the aim of several trials in undifferentiated arthritis (UA), with overall negative results. As preparatory work has revealed that only ∼30% of UA patients progress to having RA, we hypothesized that inclusion of patients without imminent RA could lead to false-negative results. We undertook this study to evaluate this hypothesis by reinvestigating the Probable Rheumatoid Arthritis: Methotrexate versus Placebo Treatment (PROMPT) trial (a 1-year course of methotrexate [MTX] versus placebo in UA) after excluding patients without a high risk of developing RA.

METHODS

A validated prediction model was used to determine the risk of RA in all patients included in the PROMPT trial. Patients with a prediction score of ≥8 (positive predictive value of ≥84% for developing RA) were considered to have a high risk of developing RA. The effect of a 1-year course of MTX during 5 years of follow-up was reinvestigated in these patients.

RESULTS

Twenty-two of the 110 patients in the PROMPT trial had a high risk of RA at baseline. In the MTX arm, 6 of 11 patients (55%) developed RA, compared to 11 of 11 patients (100%) in the placebo arm (P = 0.011). Time to RA development was longer in the MTX arm than in the placebo arm (median 22.5 months versus 3 months; P < 0.001). Drug-free remission was achieved by 4 of 11 patients (36%) in the MTX arm compared to 0 of 11 patients (0%) in the placebo arm (P = 0.031). These beneficial effects of MTX were observed both in anti-citrullinated protein antibody (ACPA)-positive and in ACPA-negative UA patients with a high risk of RA, but not in UA patients without a high risk of RA. In retrospect, 43 of 110 patients fulfilled the American College of Rheumatology/European League Against Rheumatism 2010 classification criteria for RA at baseline. In addition, beneficial effects were observed only in patients with a high prediction score.

CONCLUSION

A 1-year course of MTX delayed and prevented RA development in high-risk UA patients. This emphasizes the importance of adequate risk prediction in trials that aim to prevent RA.

Why we need a new definition of sepsis

On April 23, 2015, Kaukonen and colleagues published an article in the New England Journal of Medicine entitled "Systemic inflammatory response syndrome criteria in defining severe sepsis", which investigated the sensitivity and validity of using SIRS criteria to define intensive care unit (ICU) patients with severe sepsis. This study used admission data of over 100,000 patients in order to investigate patients with severe sepsis who either met or didn't meet SIRS criteria. The investigators found that in-hospital mortality increased linearly with the number of SIRS criteria met; raising concern that SIRS criterion is not sensitive enough. This study of SIRS criteria raises important questions about the recognition and diagnosis of severe sepsis.

Can biomarkers help us to better diagnose and manage sepsis?

The recognition over 25 years ago that the host response plays an exquisite role in sepsis, led to the today still-standard sepsis definition. Unfortunately, the inflammatory response syndrome (SIRS) criteria turned out to be less useful than anticipated, lacking sensitivity, specificity and ease of clinical application. Had novel host-response biomarkers been available by that time, it arguably would have been preferable to white blood cell count as an unspecific and not-sensitive laboratory-based SIRS criterion. Several novel markers have been put forward as sepsis markers with better diagnostic and/or prognostic potential in sepsis including inflammatory markers such as procalcitonin (PCT), presepsin, proadrenomedullin (ProADM), endothelial dysfunction markers such as P-selectin, E-selectin, intercellular cell adhesion molecule [ICAM]-1 and vascular cell adhesion molecule [VCAM]-1 and genetic markers among others. The limitations to using clinical parameters and conventional diagnostic markers for patients with clinical suspicion of sepsis may directly lead to both, under treatment of patients with severe disease needing urgent antibiotic and fluid therapy, and unnecessary and prolonged exposure to antimicrobial agents adversely affecting patient outcomes and increasing antibiotic resistance. The aim of this review is to summarize the current evidence for emerging diagnostic, prognostic, and therapeutic-response sepsis biomarkers in different infections and clinical settings, and discuss the reliability, potential benefit and limitations of these marker when used in clinical routine for sepsis management.

Prior statin use and 90-day mortality in Gram-negative and Gram-positive bloodstream infection: a prospective observational study

In several studies on patients with bloodstream infection (BSI), prior use of statins has been associated with improved survival. Gram-positive and Gram-negative bacteria alert the innate immune system in different ways. We, therefore, studied whether the relation between prior statin use and 90-day total mortality differed between Gram-positive and Gram-negative BSI. We conducted a prospective observational cohort study of 1,408 adults with BSI admitted to Levanger Hospital between January 1, 2002, and December 31, 2011. Data on the use of statins and other medications at admission, comorbidities, functional status, treatment, and outcome were obtained from the patients’ hospital records. The relation of statin use with 90-day mortality differed between Gram-negative and Gram-positive BSI (p-value for interaction 0.01). Among patients with Gram-negative BSI, statin users had significantly lower 90-day total mortality [odds ratio (OR) 0.42, 95 % confidence interval (CI) 0.23–0.75, p = 0.003]. The association remained essentially unchanged after adjusting for the effect of sex, age, functional status before the infection, and underlying diseases that were considered confounders (adjusted OR 0.38, 95 % CI 0.20–0.72, p = 0.003). A similar analysis of patients with Gram-positive BSI showed no association of statin use with mortality (adjusted OR 1.22, 95 % CI 0.69–2.17, p = 0.49). The present study suggests that prior statin use is associated with a lower 90-day total mortality in Gram-negative BSI, but not in Gram-positive BSI.

Randomised trials of human albumin for adults with sepsis: systematic review and meta-analysis with trial sequential analysis of all-cause mortality

OBJECTIVE

To assess the efficacy and safety of pooled human albumin solutions as part of fluid volume expansion and resuscitation (with or without improvement of baseline hypoalbuminaemia) in critically unwell adults with sepsis of any severity.

DESIGN

Systematic review and meta-analysis of randomised clinical trials, with trial sequential analysis, subgroup, and meta-regression analyses.

DATA SOURCES

PubMed, PubMed Central, Web of Science (includes Medline, Conference Proceedings Citation Index, Data Citation Index, Chinese Science Citation Database, CAB abstracts, Derwent Innovations Index), OvidSP (includes Embase, Ovid Medline, HMIC, PsycINFO, Maternity and Infant Care, Transport Database), Cochrane Library, clinicaltrials.gov, controlled-trials.com, online material, relevant conference proceedings, hand searching of reference lists, and contact with authors as necessary.

ELIGIBILITY CRITERIA

Prospective randomised clinical trials of adults with sepsis of any severity (with or without baseline hypoalbuminaemia) in critical or intensive care who received pooled human albumin solutions as part of fluid volume expansion and resuscitation (with or without improvement of hypoalbuminaemia) compared with those who received control fluids (crystalloid or colloid), were included if all-cause mortality outcome data were available. No restriction of language, date, publication status, or primary study endpoint was applied.

DATA EXTRACTION

Two reviewers independently assessed articles for inclusion, extracted data to assess risk of bias, trial methods, patients, interventions, comparisons, and outcome. The relative risk of all-cause mortality was calculated using a random effects model accounting for clinical heterogeneity.

PRIMARY OUTCOME MEASURE

All-cause mortality at final follow-up.

RESULTS

Eighteen articles reporting on 16 primary clinical trials that included 4190 adults in critical or intensive care with sepsis, severe sepsis, or septic shock. A median of 70.0 g daily of pooled human albumin was received over a median of 3 days by adults with a median age of 60.8 years as part of fluid volume expansion and resuscitation, with or without correction of hypoalbuminaemia. The relative risk of death was similar between albumin groups (that received a median of 175 g in total) and control fluid groups (relative risk 0.94; 95% confidence interval 0.87 to 1.01; P=0.11; I(2)=0%). Trial sequential analysis corrected the 95% confidence interval for random error (0.85 to 1.02; D(2)=0%). Eighty eight per cent of the required information size (meta-analysis sample size) of 4894 patients was achieved, and the cumulative effect size measure (z score) entered the futility area, supporting the notion of no relative benefit of albumin (GRADE quality of evidence was moderate). Evidence of no difference was also found when albumin was compared with crystalloid fluid (relative risk 0.93; 0.86 to 1.01; P=0.07; I(2)=0%) in 3878 patents (GRADE quality of evidence was high; 79.9% of required information size) or colloid fluids in 299 patients (relative risk 1.04; 0.79 to 1.38; P=0.76; I(2)=0%) (GRADE quality of evidence was very low; 5.8% of required information size). When studies at high risk of bias were excluded in a predefined subgroup analysis, the finding of no mortality benefit remained, and the cumulative z score was just outside the boundary of futility. Overall, the meta-analysis was robust to sensitivity, subgroup, meta-regression, and trial sequential analyses.

CONCLUSIONS

In this analysis, human albumin solutions as part of fluid volume expansion and resuscitation for critically unwell adults with sepsis of any severity (with or without baseline hypoalbuminaemia) were not robustly effective at reducing all-cause mortality. Albumin seems to be safe in this setting, as a signal towards harm was not detected, but this analysis does not support a recommendation for use.

Efficacy of coupled plasma filtration adsorption (CPFA) in patients with septic shock: a multicenter randomised controlled clinical trial

OBJECTIVES

Coupled plasma filtration adsorption (CPFA, Bellco, Italy), to remove inflammatory mediators from blood, has been proposed as a novel treatment for septic shock. This multicenter, randomised, non-blinded trial compared CPFA with standard care in the treatment of critically ill patients with septic shock.

DESIGN

Prospective, multicenter, randomised, open-label, two parallel group and superiority clinical trial.

SETTING

18 Italian adult, general, intensive care units (ICUs).

PARTICIPANTS

Of the planned 330 adult patients with septic shock, 192 were randomised to either have CPFA added to the standard care, or not. The external monitoring committee excluded eight ineligible patients who were erroneously included.

INTERVENTIONS

CPFA was to be performed daily for 5 days, lasting at least 10 h/day.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary endpoint was mortality at discharge from the hospital at which the patient last stayed. Secondary endpoints were: 90-day mortality, new organ failures and ICU-free days within 30 days.

RESULTS

There was no statistical difference in hospital mortality (47.3% controls, 45.1% CPFA; p=0.76), nor in secondary endpoints, namely the occurrence of new organ failures (55.9% vs 56.0%; p=0.99) or free-ICU days during the first 30 days (6.8 vs 7.5; p=0.35). The study was terminated on the grounds of futility. Several patients randomised to CPFA were subsequently found to be undertreated. An a priori planned subgroup analysis showed those receiving a CPFA dose >0.18 L/kg/day had a lower mortality compared with controls (OR 0.36, 95% CI 0.13 to 0.99).

CONCLUSIONS

CPFA did not reduce mortality in patients with septic shock, nor did it positively affect other important clinical outcomes. A subgroup analysis suggested that CPFA could reduce mortality, when a high volume of plasma is treated. Owing to the inherent potential biases of such a subgroup analysis, this result can only be viewed as a hypothesis generator and should be confirmed in future studies.

CLINICALTRIALSGOV

NCT00332371; ISRCTN24534559.

Interobserver agreement of Centers for Disease Control and Prevention criteria for classifying infections in critically ill patients

OBJECTIVES

Correct classification of the source of infection is important in observational and interventional studies of sepsis. Centers for Disease Control and Prevention criteria are most commonly used for this purpose, but the robustness of these definitions in critically ill patients is not known. We hypothesized that in a mixed ICU population, the performance of these criteria would be generally reduced and would vary among diagnostic subgroups.

DESIGN

Prospective cohort.

SETTING

Data were collected as part of a cohort of 1,214 critically ill patients admitted to two hospitals in The Netherlands between January 2011 and June 2011.

PATIENTS

Eight observers assessed a random sample of 168 of 554 patients who had experienced at least one infectious episode in the ICU. Each patient was assessed by two randomly selected observers who independently scored the source of infection (by affected organ system or site), the plausibility of infection (rated as none, possible, probable, or definite), and the most likely causative pathogen. Assessments were based on a post hoc review of all available clinical, radiological, and microbiological evidence. The observed diagnostic agreement for source of infection was classified as partial (i.e., matching on organ system or site) or complete (i.e., matching on specific diagnostic terms), for plausibility as partial (2-point scale) or complete (4-point scale), and for causative pathogens as an approximate or exact pathogen match. Interobserver agreement was expressed as a concordant percentage and as a kappa statistic.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 206 infectious episodes were observed. Agreement regarding the source of infection was 89% (183/206) and 69% (142/206) for a partial and complete diagnostic match, respectively. This resulted in a kappa of 0.85 (95% CI, 0.79-0.90). Agreement varied from 63% to 91% within major diagnostic categories and from 35% to 97% within specific diagnostic subgroups, with the lowest concordance observed in cases of ventilator-associated pneumonia. In the 142 episodes for which a complete match on source of infection was obtained, the interobserver agreement for plausibility of infection was 83% and 65% on a 2- and 4-point scale, respectively. For causative pathogen, agreement was 78% and 70% for an approximate and exact pathogen match, respectively.

CONCLUSIONS

Interobserver agreement for classifying sources of infection using Centers for Disease Control and Prevention criteria was excellent overall. However, full concordance on all aspects of the diagnosis between independent observers was rare for some types of infection, in particular for ventilator-associated pneumonia.

Harmonizing international trials of early goal-directed resuscitation for severe sepsis and septic shock: methodology of ProCESS, ARISE, and ProMISe

PURPOSE

To describe and compare the design of three independent but collaborating multicenter trials of early goal-directed resuscitation for severe sepsis and septic shock.

METHODS

We reviewed the three current trials, one each in the USA (ProCESS: protocolized care for early septic shock), Australasia (ARISE: Australasian resuscitation in sepsis evaluation), and the UK (ProMISe: protocolised management in sepsis). We used the 2010 CONSORT (consolidated standards of reporting trials) statement and the 2008 CONSORT extension for trials assessing non-pharmacologic treatments to describe and compare the underlying rationale, commonalities, and differences.

RESULTS

All three trials conform to CONSORT guidelines, address the same fundamental questions, and share key design elements. Each trial is a patient-level, equal-randomized, parallel-group superiority trial that seeks to enroll emergency department patients with inclusion criteria that are consistent with the original early goal-directed therapy (EGDT) trial (suspected or confirmed infection, two or more systemic inflammatory response syndrome criteria, and refractory hypotension or elevated lactate), is powered to detect a 6–8 % absolute mortality reduction (hospital or 90-day), and uses trained teams to deliver EGDT. Design differences appear to primarily be driven by between-country variation in health care context. The main difference between the trials is the inclusion of a third, alternative resuscitation strategy arm in ProCESS.

CONCLUSIONS

Harmonization of study design and methods between severe sepsis trials is feasible and may facilitate pooling of data on completion of the trials.

Dynamic data during hypotensive episode improves mortality predictions among patients with sepsis and hypotension

OBJECTIVES

To determine if a prediction rule for hospital mortality using dynamic variables in response to treatment of hypotension in patients with sepsis performs better than current models.

DESIGN

Retrospective cohort study.

SETTING

All ICUs at a tertiary care hospital.

PATIENTS

Adult patients admitted to ICUs between 2001 and 2007 of whom 2,113 met inclusion criteria and had sufficient data.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We developed a prediction algorithm for hospital mortality in patients with sepsis and hypotension requiring medical intervention using data from the Multiparameter Intelligent Monitoring in Intensive Care II. We extracted 189 candidate variables, including treatments, physiologic variables and laboratory values collected before, during, and after a hypotensive episode. Thirty predictors were identified using a genetic algorithm on a training set (n=1500) and validated with a logistic regression model on an independent validation set (n=613). The final prediction algorithm used included dynamic information and had good discrimination (area under the receiver operating curve=82.0%) and calibration (Hosmer-Lemeshow C statistic=10.43, p=0.06). This model was compared with Acute Physiology and Chronic Health Evaluation IV using reclassification indices and was found to be superior with an Net Reclassification Improvement of 0.19 (p<0.001) and an Integrated Discrimination Improvement of 0.09 (p<0.001).

CONCLUSIONS

Hospital mortality predictions based on dynamic variables surrounding a hypotensive event is a new approach to predicting prognosis. A model using these variables has good discrimination and calibration and offers additional predictive prognostic information beyond established ones.

Is there value in plasma cytokine measurements in patients with severe trauma and sepsis?

For the past thirty years, since IL-1β and TNFα were first cloned, there have been efforts to measure plasma cytokine concentrations in patients with severe sepsis and trauma, and to use these measurements to predict clinical outcome and response to therapies. The numbers of cytokines and chemokines that have been measured in the plasma have literally exploded with the development of multiplex immune approaches. Dozens of relatively small cohort studies have shown plasma cytokine concentrations correlating with outcome in sepsis and trauma. Despite what appears to be a consensus that plasma cytokine concentrations should be useful in the clinical setting, only two cytokines, IL-6 and procalcitonin, have approached routine clinical use. IL-6 has been used as a research tool for entry into sepsis-intervention trials, while procalcitonin is being used clinically at a large number of institutions to distinguish sepsis from other inflammatory processes. For most cytokines, the relative lack of sensitivity and specificity of individual or multiplex cytokine measurements has hindered their utility to predict clinical trajectory in individual patients. The problem rests with a general misunderstanding of cytokine biology, failing to appreciate the general paracrine nature of these mediators, the presence of binding proteins, chaperones and inhibitors in the plasma, and the rapid clearance of these proteins by binding to cell receptors and clearance predominantly by the kidney. The future of using plasma cytokine measurements as an indicator of sepsis/trauma severity or predicting outcome is generally behind us, although there is optimism that procalcitonin measurements may ultimately prove to have utility in the diagnosis of severe sepsis.

A composite score combining procalcitonin, C-reactive protein and temperature has a high positive predictive value for the diagnosis of intensive care-acquired infections

Background

Nosocomial infection diagnosis in the intensive care unit (ICU) remains a challenge. We compared routine measurements of procalcitonin (PCT), C-reactive protein (CRP), white blood cell count (WBC) and temperature in the detection of ICU-acquired infections.

Method

Prospective observational cohort study in a University hospital Medicosurgical ICU. All patients admitted to the ICU ≥ 5 days (n = 141) were included into two groups, either infected (documented infection, n = 25) or non-infected (discharged from the ICU without diagnosis of infection, n = 88).

Results

PCT, CRP, WBC and temperature progression from day −4 (D-4) to day 0 (D0) (day of infection diagnosis or ICU discharge) was analysed. Differences (Δ) were calculated as D0 levels minus the lowest preceding value. D0 PCT and CRP were significantly increased in infected compared to non-infected patients (median, 1^st and 3^rd quartiles): 3.6 ng/mL (0.92-25) for PCT, 173 mg/L (126–188) for CRP versus 0.02 ng/mL (0.1-0.9) and 57 mg/mL (31–105) respectively (p < 0.0001). In multivariate analysis, D0 temperature > 38.6°C, PCT > 1.86 ng/mL, and CRP > 88 mg/L, performed well (AUCs of 0.88, 0.84, and 0.88 respectively). The sensitivity/specificity profiles of each marker (76%/94% for temperature, 68%/91% for PCT, and 92%/70% for CRP) led to a composite score (0.068 × D0 PCT + 0.005 × D0 CRP + 0.7 × temperature) more highly specific than each component (AUC of 0.90 and sensitivity/specificity of 80%/97%).

Conclusion

Combining CRP, PCT and temperature is an approach which may increase of nosocomial infection detection in the ICU.

Randomised trials of 6% tetrastarch (hydroxyethyl starch 130/0.4 or 0.42) for severe sepsis reporting mortality: systematic review and meta-analysis

PURPOSE

To assess the impact of 6% tetrastarch [hydroxyethyl starch (HES) 130/0.4 and 130/0.42] in severe sepsis patients. The primary outcome measure was 90-day mortality.

METHODS

A structured literature search was undertaken to identify prospective randomised controlled trials (RCTs) in adult patients with severe sepsis receiving 6% tetrastarch (of potato or waxy maize origin) as part of fluid resuscitation in comparison with other non-HES fluids after randomisation in the critical care setting. A systematic review and meta-analysis were performed.

RESULTS

Six RCTs were included (n = 3,033): three from 2012 (n = 2,913) had low risk of bias. Median tetrastarch exposure was 37.4 ml/kg (range 30-43 ml/kg). Ninety-day mortality was associated with tetrastarch exposure [relative risk (RR) 1.13; 95% confidence interval (CI) 1.02-1.25; p = 0.02] compared with crystalloid. The number needed to harm (NNH) was 28.8 (95 % CI 14.6-942.5). Publication bias and statistical heterogeneity (I(2) = 0%) were not present. Tetrastarch exposure was also associated with renal replacement therapy (p = 0.01; NNH 15.7) and allogeneic transfusion support (p = 0.001; NNH 9.9). No difference between groups was observed for 28-day mortality, for comparison with colloid as control, or for waxy maize-derived tetrastarch, but power was lacking. Overall mortality was associated with tetrastarch exposure (RR 1.13; 95% CI 1.02-1.25; p = 0.02).

CONCLUSIONS

In our analysis, 6% tetrastarch as part of initial fluid resuscitation for severe sepsis was associated with harm and, as alternatives exist, in our view should be avoided.

Brachial artery reactivity in patients with severe sepsis: an observational study

Introduction

Ultrasound measurements of brachial artery reactivity in response to stagnant ischemia provide estimates of microvascular function and conduit artery endothelial function. We hypothesized that brachial artery reactivity would independently predict severe sepsis and severe sepsis mortality.

Methods

This was a combined case-control and prospective cohort study. We measured brachial artery reactivity in 95 severe sepsis patients admitted to the medical and surgical intensive care units of an academic medical center and in 52 control subjects without acute illness. Measurements were compared in severe sepsis patients versus control subjects and in severe sepsis survivors versus nonsurvivors. Multivariable analyses were also conducted.

Results

Hyperemic velocity (centimeters per cardiac cycle) and flow-mediated dilation (percentage) were significantly lower in severe sepsis patients versus control subjects (hyperemic velocity: severe sepsis = 34 (25 to 48) versus controls = 63 (52 to 81), P < 0.001; flow-mediated dilation: severe sepsis = 2.65 (0.81 to 4.79) versus controls = 4.11 (3.06 to 6.78), P < 0.001; values expressed as median (interquartile range)). Hyperemic velocity, but not flow-mediated dilation, was significantly lower in hospital nonsurvivors versus survivors (hyperemic velocity: nonsurvivors = 25 (16 to 28) versus survivors = 39 (30 to 50), P < 0.001; flow-mediated dilation: nonsurvivors = 1.90 (0.68 to 3.41) versus survivors = 2.96 (0.91 to 4.86), P = 0.12). Lower hyperemic velocity was independently associated with hospital mortality in multivariable analysis (odds ratio = 1.11 (95% confidence interval = 1.04 to 1.19) per 1 cm/cardiac cycle decrease in hyperemic velocity; P = 0.003).

Conclusions

Brachial artery hyperemic blood velocity is a noninvasive index of microvascular function that independently predicts mortality in severe sepsis. In contrast, brachial artery flow-mediated dilation, reflecting conduit artery endothelial function, was not associated with mortality in our severe sepsis cohort. Brachial artery hyperemic velocity may be a useful measurement to identify patients who could benefit from novel therapies designed to reverse microvascular dysfunction in severe sepsis and to assess the physiologic efficacy of these treatments.

Hydroxyethyl starch or saline for fluid resuscitation in intensive care

BACKGROUND

The safety and efficacy of hydroxyethyl starch (HES) for fluid resuscitation have not been fully evaluated, and adverse effects of HES on survival and renal function have been reported.

METHODS

We randomly assigned 7000 patients who had been admitted to an intensive care unit (ICU) in a 1:1 ratio to receive either 6% HES with a molecular weight of 130 kD and a molar substitution ratio of 0.4 (130/0.4, Voluven) in 0.9% sodium chloride or 0.9% sodium chloride (saline) for all fluid resuscitation until ICU discharge, death, or 90 days after randomization. The primary outcome was death within 90 days. Secondary outcomes included acute kidney injury and failure and treatment with renal-replacement therapy.

RESULTS

A total of 597 of 3315 patients (18.0%) in the HES group and 566 of 3336 (17.0%) in the saline group died (relative risk in the HES group, 1.06; 95% confidence interval [CI], 0.96 to 1.18; P=0.26). There was no significant difference in mortality in six predefined subgroups. Renal-replacement therapy was used in 235 of 3352 patients (7.0%) in the HES group and 196 of 3375 (5.8%) in the saline group (relative risk, 1.21; 95% CI, 1.00 to 1.45; P=0.04). In the HES and saline groups, renal injury occurred in 34.6% and 38.0% of patients, respectively (P=0.005), and renal failure occurred in 10.4% and 9.2% of patients, respectively (P=0.12). HES was associated with significantly more adverse events (5.3% vs. 2.8%, P<0.001).

CONCLUSIONS

In patients in the ICU, there was no significant difference in 90-day mortality between patients resuscitated with 6% HES (130/0.4) or saline. However, more patients who received resuscitation with HES were treated with renal-replacement therapy. (Funded by the National Health and Medical Research Council of Australia and others; CHEST ClinicalTrials.gov number, NCT00935168.).

Severe sepsis and systemic inflammatory response syndrome in emergency department patients with suspected severe infection

BACKGROUND

Severe sepsis is a common condition with a reported high mortality, but most studies have been confined to intensive care unit (ICU) populations. The systemic inflammatory response syndrome (SIRS) has been used to define sepsis, however its usefulness has been questioned. Our aim was to describe the prevalence and clinical impact of severe sepsis and SIRS in patients admitted from the emergency department (ED) with a suspected serious infection.

METHODS

Four hundred and four adult patients were enrolled prospectively from the ED. Variables defining severe sepsis and SIRS were measured and the relationship between severe sepsis, SIRS, and the clinical course was analyzed.

RESULTS

Infections were diagnosed in 344 patients (85%). The overall mortality rate at 28 days was 2.7%, and 4.5% of patients were treated in the ICU. Patients with severe sepsis within 24 h of admission (42%) were more likely to suffer a critical course (ICU admission 9.0%, death 5.1%; p < 0.001). While SIRS was observed in 72% of the subjects at presentation, it was not associated with severe sepsis within 24 h or a subsequent critical course. Furthermore, 23% of patients with severe sepsis within 24 h did not present with SIRS.

CONCLUSIONS

Severe sepsis was a common condition among ED patients with a clinically suspected serious infection. Mortality was low compared with results from the ICU setting, suggesting that severe sepsis is a more benign disease than earlier reported. As a tool for the definition of sepsis and for the selection of patients for clinical sepsis trials, SIRS lacks acceptable discriminative ability in an ED population with a high prevalence of serious infections.

Duration and magnitude of hypotension and monocyte deactivation in patients with community-acquired pneumonia

The objective was to examine the relationship of duration and magnitude of arterial hypotension to subsequent cellular immune suppression and cytokinemia in patients hospitalized with community-acquired pneumonia (CAP). We studied an observational cohort of 525 subjects hospitalized after presenting to the emergency department with radiographic and clinical signs of CAP. We compared the duration and magnitude of hypotension, using the cardiovascular Sequential Organ Failure Assessment (CV SOFA) subscore, to day 3 monocyte expression of human leukocyte antigen-DR (mHLA-DR), a previously validated marker of cellular immune suppression. A significant association of CV SOFA with decreased mHLA-DR expression was present in univariate analysis (P < 0.001) and persisted after adjustment for illness severity and other covariates (P = 0.01). With CV SOFA separated into components of magnitude and duration, after covariate adjustment, only duration was associated with day 3 mHLA-DR expression (P = 0.03). Levels of key proinflammatory and anti-inflammatory cytokines (interleukin 6 [IL-6], IL-10, tumor necrosis factor) increased with hypotension exposure and were also associated with mHLA-DR expression. In patients admitted with CAP, arterial hypotension over the first 3 days is associated with markers of monocyte deactivation. The duration of exposure to hypotension may be more important than the magnitude, and monocyte deactivation correlates with IL-6 and IL-10 release. These results suggest that persistent hypotension might contribute to immunosuppression following septic shock.

Comparison of outcomes by modality for critically ill patients requiring renal replacement therapy: a single-centre cohort study adjusting for time-varying illness severity and modality exposure

Prolonged intermittent renal replacement therapy (PIRRT) is a recently defined acute modality for critically ill patients, and in theory combines the superior detoxification and haemodynamic stability of continuous renal replacement therapy (CRRT) with the operational convenience and low cost of intermittent haemodialysis (iHD). We performed a retrospective cohort study for all critically ill adults treated with renal replacement therapy at our centre in Auckland, New Zealand from 1 January 2002 to 31 December 2008. The exposure of interest was modality (PIRRT, CRRT, iHD). Primary and secondary outcomes were patient mortality determined at hospital discharge and 90 days post renal replacement therapy inception, respectively. Co-variates included co-morbidity and baseline illness severity measured by Acute Physiology and Chronic Health Evaluation IV and Sepsis-Related Organ Failure Assessment (SOFA) and time-varying illness severity measured by daily SOFA scores. We used Marginal Structural Modelling to estimate mortality risk adjusting for both time-varying illness severity and modality exposure. A total of 146 patients with 633 treatment-days had sufficient data for modelling. With PIRRT as the reference, the adjusted hazard ratios for patient hospital mortality were 1.31 (0.60 to 2.90) for CRRT and 1.22 (0.21 to 2.29) for iHD. Corresponding estimates for mortality at 90 days were 0.96 (0.39 to 2.36) and 2.22 (0.49 to 10.11), respectively, reflecting the poorer longer-term prognosis of patients still on iHD at hospital discharge with delayed or non-recovery of acute kidney injury. Our study supports the recent increased use of PIRRT, which within limits can be regarded as safe and effective.

The PRECISE RCT: evolution of an early septic shock fluid resuscitation trial

Severe sepsis and septic shock are the most common reasons for admission to an intensive care unit; and the risk of death is substantial, estimated at approximately 40%. Evidence suggests that early resuscitation strategies that include the use of resuscitation fluids, antibiotics, blood, and inotropes reduce death. Although fluid resuscitation is an immediate life-saving intervention, a fundamental question that remains unanswered is whether the type of resuscitation fluid impacts survival when it is initiated very early in the course of septic shock. A randomized controlled trial published in 2008 confirmed that hydroxyethyl starch fluids cause acute renal failure defined by the requirement for renal replacement therapy. In contrast, a subgroup analysis from a randomized controlled trial suggests that 4% albumin fluid may reduce death from severe sepsis; however, these findings require confirmation in a large randomized trial. Our team is planning a pragmatic early septic shock fluid resuscitation trial that will compare the effectiveness of 5% albumin vs normal saline on 90-day mortality (PRECISE). In this article, we summarize the scientific rationale and inherent challenges associated with the conduct of PRECISE, the background work and planning elements that have been undertaken, and the PRECISE RCT protocol with rationale and justifications provided for the chosen population, the interventions, and the outcome measures.

Understanding the potential role of statins in pneumonia and sepsis

OBJECTIVE

To examine the association of statin use with clinical outcomes and circulating biomarkers in community-acquired pneumonia and sepsis.

DESIGN

Multicenter inception cohort study.

SETTING

Emergency departments of 28 U.S. hospitals.

PATIENTS

A total of 1895 subjects hospitalized with community-acquired pneumonia.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Our approach consisted of two different comparison cohorts, each reflecting methods used in prior publications in this area. We first compared subjects with prior statin use (prior use cohort), defined as a history of statin use in the week before admission, with those with no prior use. We then compared prior statin users whose statins were continued inhospital (continued use cohort) with those with either no prior use or no inhospital use. We adjusted for patient characteristics, including demographics, comorbid conditions, and illness severity, and accounted for healthy user effect and indication bias using propensity analysis. We determined risk of severe sepsis and 90-day mortality. We measured markers inflammation (tumor necrosis factor, interleukin-6, interleukin-10), coagulation (antithrombin, factor IX, plasminogen activator inhibitor, d-dimer, thrombin antithrombin complex), and lymphocyte cell surface protein expression during the first week of hospitalization. There were no differences in severe sepsis risk between statin users and nonusers for prior (30.8% vs. 30.7%, p = .98) or continued statin use (30.2% vs. 30.8%, p = .85) in univariate analyses and after adjusting for patient characteristics and propensity for statin use. Ninety-day mortality was similar in prior statin users (9.2% vs. 12.0%, p = .11) and lower in continued statin users (7.9% vs. 12.1%, p = .02). After adjusting for patient characteristics and propensity for statin use, there was no mortality benefit for prior (odds ratio, 0.90 [0.63-1.29]; p = .57) or continued statin use (odds ratio, 0.73 [0.47-1.13]; p = .15). Only antithrombin activity over time was higher in statin subjects, yet the magnitude of the difference was modest. There were no differences in other coagulation, inflammatory, or lymphocyte cell surface markers.

CONCLUSIONS

We found no evidence of a protective effect for statin use on clinical outcomes and only modest differences in circulating biomarkers in community-acquired pneumonia, perhaps as a result of healthy user effects and indication bias.

The septic milieu triggers expression of spliced tissue factor mRNA in human platelets

BACKGROUND

Activated platelets have previously-unrecognized mechanisms of post-transcriptional gene expression that may influence hemostasis and inflammation. A novel pathway involves splicing of pre-mRNAs in resting platelets to mature, translatable mRNAs in response to cellular activation.

OBJECTIVES

We asked if bacterial products and host agonists present in the septic milieu induce tissue factor pre-mRNA splicing in platelets from healthy subjects. In parallel, we asked if spliced tissue factor (TF) mRNA is present in platelets from septic patients in a proof-of-principle analysis.

PATIENTS/METHODS

TF pre-mRNA and mRNA expression patterns were characterized in platelets from septic patients and in platelets isolated from healthy subjects activated with bacteria, toxins and inflammatory agonists. Procoagulant activity was also measured.

RESULTS AND CONCLUSIONS

Live bacteria, staphylococcal α-toxin and lipopolysaccharide (LPS) induced TF pre-mRNA splicing in platelets isolated from healthy subjects. Toxin-stimulated platelets accelerated plasma clotting, a response that was blocked by a previously-characterized splicing inhibitor and by an anti-tissue factor antibody. Platelets from septic patients expressed spliced TF mRNA, whereas it was absent from unselected and age-matched control subjects. Tissue factor-dependent procoagulant activity was elevated in platelets from a subset of septic patients. Thus, bacterial and host factors induce splicing of TF pre-mRNA, expression of TF mRNA and tissue factor-dependent clotting activity in human platelets. TF mRNA is present in platelets from some septic patients, indicating that it may be a marker of altered platelet phenotype and function in sepsis and that splicing pathways are induced in this syndrome.

Persistent organ dysfunction plus death: a novel, composite outcome measure for critical care trials

INTRODUCTION

Due to resource limitations, few critical care interventions have been rigorously evaluated with adequately powered randomized clinical trials (RCTs). There is a need to improve the efficiency of RCTs in critical care so that more definitive high quality RCTs can be completed with the available resources. The objective of this study was to validate and demonstrate the utility of a novel composite outcome measure, persistent organ dysfunction (POD) plus death, for clinical trials of critically ill patients.

METHODS

We performed a secondary analysis of a dataset from a prospective randomized trial involving 38 intensive care units (ICUs) in Canada, Europe, and the United States. We define POD as the persistence of organ dysfunction requiring supportive technologies during the convalescent phase of critical illness and it is present when a patient has an ongoing requirement for vasopressors, dialysis, or mechanical ventilation at the outcome assessments time points. In 600 patients enrolled in a randomized trial of nutrition therapy and followed prospectively for six months, we evaluated the prevalence of POD and its association with outcome.

RESULTS

At 28 days, 2.3% of patients had circulatory failure, 13.7% had renal failure, 8.7% had respiratory failure, and 27.2% had died, for an overall prevalence of POD + death = 46.0%. Of survivors at Day 28, those with POD, compared to those without POD, had a higher mortality rate in the six-month follow-up period, had longer ICU and hospital stays, and a reduced quality of life at three months. Given these rates of POD + death and using a two-sided Chi-squared test at alpha = 0.05, we would require 616 patients per arm to detect a 25% relative risk reduction (RRR) in mortality, but only 286 per arm to detect the same RRR in POD + mortality.

CONCLUSIONS

POD + death may be a valid composite outcome measure and compared to mortality endpoints, may reduce the sample size requirements of clinical trials of critically ill patients. Further validation in larger clinical trials is required.

Multicenter clinical trials in sepsis: understanding the big picture and building a successful operation at your hospital

Only through adequately designed and adequately conducted clinical trials can new treatments be found for the benefit of the septic patient. Over the past 20 years, tens of thousands of patients have been enrolled in sepsis clinical trials with little success. These efforts, however, have not been without worth. Much has been learned and the knowledge gained has changed our approach to trial design in this very difficult field. Animal studies are better designed to match the clinical picture of severe sepsis. Phase II studies are more carefully engineered to answer questions about the most suitable target population and end points. Trial conduct likely benefits from use of CROs and a CCC. The future of clinical trials may include more standardization of sepsis management across investigative sites. Before the decision is made to become an investigative site in a multicenter industry-sponsored clinical trial in sepsis or severe sepsis, it is important to recognize what is required to succeed. Once these key-to-success elements are in place, members of the investigative team are more likely to realize the satisfaction and career growth from becoming a successful site. The most professional satisfaction comes from the knowledge of contributing to original science in the field of the sepsis.

Activated protein C N-linked glycans modulate cytoprotective signaling function on endothelial cells

Activated protein C (APC) has potent anticoagulant and anti-inflammatory properties that limit clot formation, inhibit apoptosis, and protect vascular endothelial cell barrier integrity. In this study, the role of N-linked glycans in modulating APC endothelial cytoprotective signaling via endothelial cell protein C receptor/protease-activated receptor 1 (PAR1) was investigated. Enzymatic digestion of APC N-linked glycans (PNG-APC) decreased the APC concentration required to achieve half-maximal inhibition of thrombin-induced endothelial cell barrier permeability by 6-fold. Furthermore, PNG-APC exhibited increased protection against staurosporine-induced endothelial cell apoptosis when compared with untreated APC. To investigate the specific N-linked glycans responsible, recombinant APC variants were generated in which each N-linked glycan attachment site was eliminated. Of these, APC-N329Q was up to 5-fold more efficient in protecting endothelial barrier function when compared with wild type APC. Based on these findings, an APC variant (APC-L38D/N329Q) was generated with minimal anticoagulant activity, but 5-fold enhanced endothelial barrier protective function and 30-fold improved anti-apoptotic function when compared with wild type APC. These data highlight the previously unidentified role of APC N-linked glycosylation in modulating endothelial cell protein C receptor-dependent cytoprotective signaling via PAR1. Furthermore, our data suggest that plasma β-protein C, characterized by aberrant N-linked glycosylation at Asn-329, may be particularly important for maintenance of APC cytoprotective functions in vivo.

The prevalence of anemia and its association with 90-day mortality in hospitalized community-acquired pneumonia

Background

The prevalence of anemia in the intensive care unit is well-described. Less is known, however, of the prevalence of anemia in hospitalized patients with lesser illness severity or without organ dysfunction. Community-acquired pneumonia (CAP) is one of the most frequent reasons for hospitalization in the United States (US), affecting both healthy patients and those with comorbid illness, and is typically not associated with acute blood loss. Our objective was to examine the development and progression of anemia and its association with 90d mortality in 1893 subjects with CAP presenting to the emergency departments of 28 US academic and community hospitals.

Methods

We utilized hemoglobin values obtained for clinical purposes, classifying subjects into categories consisting of no anemia (hemoglobin >13 g/dL), at least borderline (≤ 13 g/dL), at least mild (≤ 12 g/dL), at least moderate (≤ 10 g/dL), and severe (≤ 8 g/dL) anemia. We stratified our results by gender, comorbidity, ICU admission, and development of severe sepsis. We used multivariable logistic regression to determine factors independently associated with the development of moderate to severe anemia and to examine the relationship between anemia and 90d mortality.

Results

A total of 8240 daily hemoglobin values were measured in 1893 subjects. Mean (SD) number of hemoglobin values per patient was 4.4 (4.0). One in three subjects (33.9%) had at least mild anemia at presentation, 3 in 5 (62.1%) were anemic at some point during their hospital stay, and 1 in 2 (54.5%) survivors were discharged from the hospital anemic. Anemia increased with illness severity and was more common in those with comorbid illnesses, female gender, and poor outcomes. Yet, even among men and in those with no comorbidity or only mild illness, anemia during hospitalization was common (~55% of subjects). When anemia was moderate to severe (≤ 10 g/dL), its development was independently associated with increased 90d mortality, even among hospital survivors.

Conclusions

Anemia was common in hospitalized CAP and independently associated with 90d mortality when hemoglobin values were 10 g/dL or less. Whether prevention or treatment of CAP-associated anemia would improve clinical outcomes remains to be seen.

Animal models of sepsis

In this review, we start with a general discussion of relevant factors that can determine the validity of a sepsis animal model. We briefly review some of the currently used animal models of sepsis (small animal models and large animal models). We discuss the clinical relevance of animal models in sepsis research today and address potential reasons for the apparent underperformance of animal models in predicting therapeutic success of novel drugs in clinical trials.

Multicenter clinical trials in sepsis: understanding the big picture and building a successful operation at your hospital

The environment for clinical trials in sepsis has long been identified as challenging and full of road blocks and land mines. Unlike many other diagnoses (ie, cancer, acute myocardial infarction) relevance of animal studies and predictive capability of phase II trials for dose generation is less clear. The members of the investigative team must realize the essentials for success in a multicenter clinical trial. It is also useful and important to understand the big picture of clinical trial development as well as properly functioning interfaces among sponsor, contract research organizations, and investigative sites. Because early enrollment into sepsis clinical trials is usually required, collaboration between emergency medicine and critical care is needed.

[Evaluation of eosinopenia as an infection marker in critical care patients]

INTRODUCTION

To evaluate eosinopenia as an early marker of infection.

DESIGN

Retrospective cohort study.

PATIENTS

Medical-surgical ICU patients with high severity scores.

MAIN VARIABLES

Data on days 1-5: Demographic data, diagnosis, clinical repercussion, mechanical ventilation, clinical development, length of stay, APACHE II, leukocytes, SOFA and lactate. Patients divided into two groups: with and without infection. ROCs (receiver operator characteristic) curves were plotted and best point for discriminative values determined.

RESULTS

244 patients were included: 22.5% with infection. 52.9% medical, 22.5% surgical and 24.6% polytrauma patients. APACHE II: 14.9+/-8.9. In a logistic regression model of infection (dependent variable infection), the independent variables were: APACHE II, SOFA, monocytes and eosinophils. The ROC curve for eosinophils on the first day: area of 0.72; the best cut off value is 10 eosinophils/microl, with sensitivity (S): 64.8% and specificity (Sp): 70.9%. In medical patients, the area under curve is 0.80, with ideal cut off value of 9 eosinophils/microl; in surgical patients is 0.53, with a cut off ideal value of 54. We combined eosinophils and monocytes: a cut-off value of 9 eosinophils/microl in medical patients with >400 monocytes/microl, has: S: 86.7%, Sp: 74.7%, a positive predictive value (PPV) of 40.6% and a negative predictive value (NPV) 96.6%; in postsurgical patients with <400 monocytes/microl and a cut-off value of 54 eosinophils: S: 100%, Sp: 20%, PPV: 52.9% and NPV: 100%.

CONCLUSIONS

In a medical-surgical ICU, the capacity to discriminate infection through examining eosinopenia is not high. It could be useful to rule out infection if we combined eosinopenia with monocytes count.

Prevalence and significance of coagulation abnormalities in community-acquired pneumonia

Coagulation abnormalities are common in severe pneumonia and sepsis, yet little is known about the presence of coagulopathy or its significance in patients with lesser illness severity. We examined coagulation abnormalities in 939 subjects hospitalized with community-acquired pneumonia (CAP) in 28 US hospitals, hypothesizing that abnormalities would increase with illness severity and poor outcomes. We measured plasma coagulation markers (D-dimer, plasminogen activator inhibitor [PAI], antithrombin, factor IX, and thrombin-antithrombin complex [TAT]) at the time of patient presentation to the emergency department and daily during the first wk of hospitalization. Day-1 clinical laboratory test results for international normalized ratio, activated partial thromboplastin time, and platelet count were recorded from the medical record. In our cohort, 32.5% of patients developed severe sepsis and 11.1% died by d 90. Day-1 coagulation abnormalities were common, especially for D-dimer (80.6%) and TAT (36.0%), and increased with illness severity and poor outcomes. However, abnormalities also occurred in those patients who never developed organ dysfunction and differences between groups were modest. The proportion of patients with abnormalities changed over time, yet the magnitude of change was small and not always in the direction of normality. Many patients remaining in the hospital continued to manifest coagulation abnormalities on d 7, especially for D-dimer (86.5%) and TAT (36.9%). In conclusion, coagulation abnormalities were common and persistent in CAP patients, even among the least ill. These findings underscore the complexity of the coagulation response to infection and may offer insights into coagulation-based therapeutics in clinical sepsis trials.