Letter: Exploring the clinical utility of ammonia in critically ill patients with cirrhosis: More to do? Authors' reply

This article is linked to Cardoso et al papers. To view these articles, visit https://doi.org/10.1111/apt.17650 and https://doi.org/10.1111/apt.17698

Early serum ammonia variation in critically ill patients with cirrhosis: A multicentre cohort study

BACKGROUND

Serum ammonia variation in critically ill patients with cirrhosis has been poorly studied.

AIM

To describe and assess the impact of serum ammonia variation in these patients' outcomes.

METHODS

We studied patients ≥18 years old admitted to the intensive care units (ICUs) at University of Alberta Hospital (Edmonton, Canada) and Curry Cabral Hospital (Lisbon, Portugal; derivation cohort, n = 492) and Northwestern University Hospital (Chicago, USA; validation cohort, n = 600) between January 2010 and December 2021. Primary exposure was ICU days 1-3 serum ammonia. Primary endpoint was all-cause hospital mortality.

RESULTS

In the derivation cohort, 330 (67.1%) patients were male and median (IQR) age was 57 (50-63) years. On ICU day 1, median ammonia was higher in patients with grade 3/4 hepatic encephalopathy (HE) than those with grade 2 HE or grade 0/1 HE (112 vs. 88 vs. 77 μmoL/L, respectively; p < 0.001). Furthermore, medium ammonia was higher in hospital non-survivors than survivors (99 vs. 86 μmol/L; p < 0.030). Following adjustment for significant confounders (age, HE, vasopressor use and renal replacement therapy delivery), higher ICU day 2 ammonia was independently associated with higher hospital mortality (adjusted OR per each 10 μmoL/L increment [95% CI] = 1.11 [1.01-1.21]; p = 0.024). In the validation cohort, this model with serial ammonia (ICU days 1 and 3) predicted hospital mortality with reasonably good discrimination (c-statistic = 0.73) and calibration (R2  = 0.19 and Brier score = 0.17).

CONCLUSIONS

Among patients with cirrhosis in the ICU, early serum ammonia variation was independently associated with hospital mortality. In this context, serial serum ammonia may have prognostic value.

ERS/ESICM/ESCMID/ALAT guidelines for the management of severe community-acquired pneumonia

PURPOSE

Severe community-acquired pneumonia (sCAP) is associated with high morbidity and mortality, and whilst European and non-European guidelines are available for community-acquired pneumonia, there are no specific guidelines for sCAP.

METHODS

The European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID), and Latin American Thoracic Association (ALAT) launched a task force to develop the first international guidelines for sCAP. The panel comprised a total of 18 European and four non-European experts, as well as two methodologists. Eight clinical questions for sCAP diagnosis and treatment were chosen to be addressed. Systematic literature searches were performed in several databases. Meta-analyses were performed for evidence synthesis, whenever possible. The quality of evidence was assessed with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Evidence to Decision frameworks were used to decide on the direction and strength of recommendations.

RESULTS

Recommendations issued were related to diagnosis, antibiotics, organ support, biomarkers and co-adjuvant therapy. After considering the confidence in effect estimates, the importance of outcomes studied, desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention and implications to health equity, recommendations were made for or against specific treatment interventions.

CONCLUSIONS

In these international guidelines, ERS, ESICM, ESCMID, and ALAT provide evidence-based clinical practice recommendations for diagnosis, empirical treatment, and antibiotic therapy for sCAP, following the GRADE approach. Furthermore, current knowledge gaps have been highlighted and recommendations for future research have been made.

ERS/ESICM/ESCMID/ALAT guidelines for the management of severe community-acquired pneumonia

BACKGROUND

Severe community-acquired pneumonia (sCAP) is associated with high morbidity and mortality, and while European and non-European guidelines are available for community-acquired pneumonia, there are no specific guidelines for sCAP.

MATERIALS AND METHODOLOGY

The European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and Latin American Thoracic Association (ALAT) launched a task force to develop the first international guidelines for sCAP. The panel comprised a total of 18 European and four non-European experts, as well as two methodologists. Eight clinical questions for sCAP diagnosis and treatment were chosen to be addressed. Systematic literature searches were performed in several databases. Meta-analyses were performed for evidence synthesis, whenever possible. The quality of evidence was assessed with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Evidence to Decision frameworks were used to decide on the direction and strength of recommendations.

RESULTS

Recommendations issued were related to diagnosis, antibiotics, organ support, biomarkers and co-adjuvant therapy. After considering the confidence in effect estimates, the importance of outcomes studied, desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention and implications to health equity, recommendations were made for or against specific treatment interventions.

CONCLUSIONS

In these international guidelines, ERS, ESICM, ESCMID and ALAT provide evidence-based clinical practice recommendations for diagnosis, empirical treatment and antibiotic therapy for sCAP, following the GRADE approach. Furthermore, current knowledge gaps have been highlighted and recommendations for future research have been made.

The impact of multidrug-resistant microorganisms on critically ill patients with cirrhosis in the intensive care unit: a cohort study

The impact of multidrug-resistant (MDR) colonization and MDR infection in critically ill cirrhosis patients remains unclear. We assessed the association of MDR colonization and MDR infection with these patients' survival. Observational cohort study including adult cirrhosis patients admitted to 5 intensive care units at Northwestern Memorial Hospital (Chicago, Illinois, USA) on January 1, 2010, to December 31, 2017. Patients admitted for elective liver transplant or with previous liver transplant were excluded. Patients were screened for MDR colonization on intensive care unit admission. Infection diagnoses during the intensive care unit stay were considered. The primary endpoint was hospital transplant-free survival. Among 600 patients included, 362 (60%) were men and median (interquartile range) age was 58.0 (49.0, 64.0) years. Median (interquartile range) Model for End-stage Liver Disease, Sequential Organ Failure Assessment, and Chronic Liver Failure-Acute-on-Chronic Liver Failure scores on intensive care unit day 1 were 28.0 (20.0, 36.0), 9.0 (6.0, 13.0), and 55.0 (48.0, 64.0), respectively. Overall, 76 (13%) patients were transplanted and 443 (74%) survived the hospital stay. Infections were diagnosed in 347 (58%) patients: pneumonia in 197 (33%), urinary tract infection in 119 (20%), peritonitis in 93 (16%), bloodstream infection in 99 (16%), Clostridium difficile colitis in 9 (2%), and catheter tip infection in 7 (1%). MDR colonization and MDR infection were identified in 200 (33%) and 69 (12%) patients, respectively. MDR colonization was associated with MDR infection (p < 0.001). MDR colonization or MDR infection was associated with higher number and duration of antibiotics (p < 0.001). Following adjustment for covariables (age, sex, etiology, portal hypertension, and Sequential Organ Failure Assessment score), MDR colonization [OR (95% CI), 0.64 (0.43, 0.95)] or MDR infection [adjusted OR (95% CI), 0.22 (0.12, 0.40)] were independently associated with lower transplant-free survival. Among critically ill cirrhosis patients, MDR colonization or MDR infection portended a worse prognosis.

485. A hypermutator strain of Pseudomonas aeruginosa in a COVID-19 patient with ventilator-associated pneumonia

Background

P. aeruginosa is a cause of hospital-acquired and ventilator-associated pneumonia. Hypermutator P. aeruginosa strains have been described in patients with cystic fibrosis and chronic respiratory infections but are rare in patients with acute P. aeruginosa infection. This case describes a hypermutator strain of P. aeruginosa found in a patient with COVID-19-associated acute respiratory distress syndrome (ARDS).

Methods

Serial respiratory and blood cultures were collected. Short-read sequencing libraries were prepared using the Illumina Nextera XT kit, and whole-genome sequencing was performed using the Illumina NextSeq platform. Long-read sequencing libraries were prepared from unsheared genomic DNA using ligation sequencing kit SQK-LSK109 and sequenced on the Oxford MinION platform. Single nucleotide variants were identified by aligning reads from each isolate to the complete genome of the first available clinical isolate. Hypermutator assays were performed by measuring the mutation frequency rate for rifampin resistance. Antibiotic minimal inhibitory concentrations (MICs) were performed. Growth curves were performed with a starting OD600 of 0.1 with measurements taken every 30 minutes for 24 hours.

Results

Seventeen respiratory and five blood isolates were obtained throughout 62 days of hospitalization. Fourteen of the 22 isolates exhibited hypermutator phenotypes by rifampin resistance assays, which demonstrated rapid accumulation of mutations. All five bloodstream isolates were hypermutators. MIC testing noted increased resistance to aminoglycosides, fluoroquinolones, and aztreonam in the hypermutator isolates. All bloodstream isolates descended from a single progenitor noted on whole-genome sequencing. Each hypermutator strain contained a mutation in the mismatch repair gene mutL, previously associated with the hypermutator phenotype.

Genetic Tree of Patient Isolates

The genetic tree highlights hypermutator versus non-hypermutator single nucleotide variants

Conclusion

This case was notable for multiple isolates of hypermutator P. aeruginosa that persisted over weeks. The patient’s COVID-19 infection and acute respiratory distress syndrome may have facilitated persistence of the P. aeruginosa lineage, allowing a hypermutator lineage to emerge.

Disclosures

All Authors: No reported disclosures.

First report of Pseudomonas nitroreducens cultured from the lungs of a patient with pneumonia

A man in his 50s with neutropenic fever and multifocal lung opacities was diagnosed with a viral pneumonia. A small number of bacteria grown from bronchoalveolar lavage fluid collected during a repeat bronchoscopy were initially identified as Pseudomonas aeruginosa by VITEK-2 and mass spectrometry platforms. Whole-genome sequencing, however, subsequently demonstrated that the bacteria were Pseudomonas nitroreducens, representing the first known case of P. nitroreducens cultured from human lungs.

International Perspective on the New 2019 American Thoracic Society/Infectious Diseases Society of America Community-Acquired Pneumonia Guideline: A Critical Appraisal by a Global Expert Panel

In 2019, the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA) issued a substantial revision of the 2007 guideline on community-acquired pneumonia (CAP). Despite the fact that generalization of infectious disease guidelines is limited because of substantial geographic differences in microbiologic etiology and antimicrobial resistance, the ATS/IDSA guideline is frequently applied outside the United States. Therefore, this project aimed to give a perspective on the ATS/IDSA CAP recommendations related to the management of CAP outside the United States. For this, an expert panel composed of 14 international key opinion leaders in the field of CAP from 10 countries across five continents, who were not involved in producing the 2019 guideline, was asked to subjectively name the five most useful changes, the recommendation viewed most critically, and the recommendation that cannot be applied to their respective region. There was no formal consensus process, and the article reflects different opinions. Recommendations welcomed by most of the international pneumonia experts included the abandonment of the concept of “health-care-associated pneumonia,” the more restrictive indication for empiric macrolide treatment in outpatients, the increased emphasis on microbiologic diagnostics, and addressing the use of corticosteroids. Main criticisms included the somewhat arbitrary choice of a 25% resistance threshold for outpatient macrolide monotherapy. Experts from areas with elevated mycobacterial prevalence particularly opposed the recommendation of fluoroquinolones, even as an alternative.

Treatment of Community-Acquired Pneumonia in Immunocompromised Adults: A Consensus Statement Regarding Initial Strategies

Background

Community-acquired pneumonia (CAP) guidelines have improved the treatment and outcomes of patients with CAP, primarily by standardization of initial empirical therapy. But current society-published guidelines exclude immunocompromised patients.

Research Question

There is no consensus regarding the initial treatment of immunocompromised patients with suspected CAP.

Study Design and Methods

This consensus document was created by a multidisciplinary panel of 45 physicians with experience in the treatment of CAP in immunocompromised patients. The Delphi survey methodology was used to reach consensus.

Results

The panel focused on 21 questions addressing initial management strategies. The panel achieved consensus in defining the population, site of care, likely pathogens, microbiologic workup, general principles of empirical therapy, and empirical therapy for specific pathogens.

Interpretation

This document offers general suggestions for the initial treatment of the immunocompromised patient who arrives at the hospital with pneumonia.

Identification and validation of biomarkers of persistent acute kidney injury: the RUBY study

Purpose

The aim of the RUBY study was to evaluate novel candidate biomarkers to enable prediction of persistence of renal dysfunction as well as further understand potential mechanisms of kidney tissue damage and repair in acute kidney injury (AKI).

Methods

The RUBY study was a multi-center international prospective observational study to identify biomarkers of the persistence of stage 3 AKI as defined by the KDIGO criteria. Patients in the intensive care unit (ICU) with moderate or severe AKI (KDIGO stage 2 or 3) were enrolled. Patients were to be enrolled within 36 h of meeting KDIGO stage 2 criteria. The primary study endpoint was the development of persistent severe AKI (KDIGO stage 3) lasting for 72 h or more (NCT01868724).

Results

364 patients were enrolled of whom 331 (91%) were available for the primary analysis. One hundred ten (33%) of the analysis cohort met the primary endpoint of persistent stage 3 AKI. Of the biomarkers tested in this study, urinary C–C motif chemokine ligand 14 (CCL14) was the most predictive of persistent stage 3 AKI with an area under the receiver operating characteristic curve (AUC) (95% CI) of 0.83 (0.78–0.87). This AUC was significantly greater than values for other biomarkers associated with AKI including urinary KIM-1, plasma cystatin C, and urinary NGAL, none of which achieved an AUC > 0.75.

Conclusion

Elevated urinary CCL14 predicts persistent AKI in a large heterogeneous cohort of critically ill patients with severe AKI. The discovery of CCL14 as a predictor of persistent AKI and thus, renal non-recovery, is novel and could help identify new therapeutic approaches to AKI.

Electronic supplementary material

The online version of this article (10.1007/s00134-019-05919-0) contains supplementary material, which is available to authorized users.

Summary of the international clinical guidelines for the management of hospital-acquired and ventilator-acquired pneumonia

A summary of the evidence and recommendations made in the ERS/ESICM/ESCMID/ALAT guidelines for the management of hospital-acquired pneumonia and ventilator-associated pneumonia http://ow.ly/S3zA30iZfLa.

Streamlining Safety Data Collection in Hospital-Acquired Bacterial Pneumonia and Ventilator-Associated Bacterial Pneumonia Trials: Recommendations of the Clinical Trials Transformation Initiative Antibacterial Drug Development Project Team

BACKGROUND

Resistant bacteria are one of the leading causes of hospital-acquired/ventilator-associated bacterial pneumonia (HABP/VABP). HABP/VABP trials are complex and difficult to conduct due to the large number of medical procedures, adverse events, and concomitant medications involved. Differences in the legislative frameworks between different regions of the world may also lead to excessive data collection. The Clinical Trials Transformation Initiative (CTTI) seeks to advance antibacterial drug development (ABDD) by streamlining clinical trials to improve efficiency and feasibility while maintaining ethical rigor, patient safety, information value, and scientific validity.

METHODS

In 2013, CTTI engaged a multidisciplinary group of experts to discuss challenges impeding the conduct of HABP/VABP trials. Separate workstreams identified challenges associated with current data collection processes. Experts defined "data collection" as the act of capturing and reporting certain data on the case report form as opposed to recording of data as part of routine clinical care. The ABDD Project Team developed strategies for streamlining safety data collection in HABP/VABP trials using a Quality by Design approach.

RESULTS

Current safety data collection processes in HABP/VABP trials often include extraneous information. More targeted strategies for safety data collection in HABP/VABP trials will rely on optimal protocol design and prespecification of which safety data are essential to satisfy regulatory reporting requirements.

CONCLUSIONS

A consensus and a cultural change in clinical trial design and conduct, which involve recognition of the need for more efficient data collection, are urgently needed to advance ABDD and to improve HABP/VABP trials in particular.

International ERS/ESICM/ESCMID/ALAT guidelines for the management of hospital-acquired pneumonia and ventilator-associated pneumonia: Guidelines for the management of hospital-acquired pneumonia (HAP)/ventilator-associated pneumonia (VAP) of the European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and Asociación Latinoamericana del Tórax (ALAT)

The most recent European guidelines and task force reports on hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) were published almost 10 years ago. Since then, further randomised clinical trials of HAP and VAP have been conducted and new information has become available. Studies of epidemiology, diagnosis, empiric treatment, response to treatment, new antibiotics or new forms of antibiotic administration and disease prevention have changed old paradigms. In addition, important differences between approaches in Europe and the USA have become apparent.The European Respiratory Society launched a project to develop new international guidelines for HAP and VAP. Other European societies, including the European Society of Intensive Care Medicine and the European Society of Clinical Microbiology and Infectious Diseases, were invited to participate and appointed their representatives. The Latin American Thoracic Association was also invited.A total of 15 experts and two methodologists made up the panel. Three experts from the USA were also invited (Michael S. Niederman, Marin Kollef and Richard Wunderink).Applying the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology, the panel selected seven PICO (population-intervention-comparison-outcome) questions that generated a series of recommendations for HAP/VAP diagnosis, treatment and prevention.

Carbapenem-Resistant Enterobacteriaceae Infections: Results From a Retrospective Series and Implications for the Design of Prospective Clinical Trials

BACKGROUND

The increasing incidence of multidrug-resistant Gram negatives, such as carbapenem-resistant Enterobacteriaceae (CRE), has resulted in a critical need for new antimicrobials. Most studies of new antimicrobials have been performed in patients with nondrug-resistant pathogens. We performed a retrospective analysis of patients with CRE infections to inform the design of phase 3 clinical trials.

METHODS

This was a retrospective study at 22 centers in 4 countries. Baseline data, treatment, and outcomes were collected in patients with complicated urinary tract infection (cUTI)/acute pyelonephritis (AP), hospital-acquired bacterial pneumonia (HABP), ventilator-associated bacterial pneumonia (VABP), and bacteremia due to CRE.

RESULTS

Two hundred fifty-six cases of CRE infection were identified: 75 cUTI/AP, 21 HABP, 20 VABP, and 140 bacteremia. The patient population had significant comorbidities: 32.8% had chronic renal insufficiency, and 26.2% were immunocompromised. Illness severity at presentation was high: 29.3% presented with septic shock. Treatment regimens varied widely; however, a majority of patients received combination therapy. Outcomes were universally poor (28-day mortality was 28.1%) across all sites of infection, particularly in dialysis patients and those with sepsis.

CONCLUSIONS

The CRE infections occured in patients with substantial comorbidities and were associated with high mortality and low rates of clinical cure with available antibiotics. Patients with these comorbidities are often excluded from enrollment in clinical trials for registration of new drugs. These results led to changes in the inclusion/exclusion criteria of a phase 3 trial to better represent the patient population with CRE infections and enable enrollment. Observational studies may become increasingly important to guide clinical trial design, inform on the existing standard of care, and provide an external control for subsequent trials.

Validation of cell-cycle arrest biomarkers for acute kidney injury using clinical adjudication

RATIONALE

We recently reported two novel biomarkers for acute kidney injury (AKI), tissue inhibitor of metalloproteinases (TIMP)-2 and insulin-like growth factor binding protein 7 (IGFBP7), both related to G1 cell cycle arrest.

OBJECTIVES

We now validate a clinical test for urinary [TIMP-2]·[IGFBP7] at a high-sensitivity cutoff greater than 0.3 for AKI risk stratification in a diverse population of critically ill patients.

METHODS

We conducted a prospective multicenter study of 420 critically ill patients. The primary analysis was the ability of urinary [TIMP-2]·[IGFBP7] to predict moderate to severe AKI within 12 hours. AKI was adjudicated by a committee of three independent expert nephrologists who were masked to the results of the test.

MEASUREMENTS AND MAIN RESULTS

Urinary TIMP-2 and IGFBP7 were measured using a clinical immunoassay platform. The primary endpoint was reached in 17% of patients. For a single urinary [TIMP-2]·[IGFBP7] test, sensitivity at the prespecified high-sensitivity cutoff of 0.3 (ng/ml)(2)/1,000 was 92% (95% confidence interval [CI], 85-98%) with a negative likelihood ratio of 0.18 (95% CI, 0.06-0.33). Critically ill patients with urinary [TIMP-2]·[IGFBP7] greater than 0.3 had seven times the risk for AKI (95% CI, 4-22) compared with critically ill patients with a test result below 0.3. In a multivariate model including clinical information, urinary [TIMP-2]·[IGFBP7] remained statistically significant and a strong predictor of AKI (area under the curve, 0.70, 95% CI, 0.63-0.76 for clinical variables alone, vs. area under the curve, 0.86, 95% CI, 0.80-0.90 for clinical variables plus [TIMP-2]·[IGFBP7]).

CONCLUSIONS

Urinary [TIMP-2]·[IGFBP7] greater than 0.3 (ng/ml)(2)/1,000 identifies patients at risk for imminent AKI. Clinical trial registered with www.clinicaltrials.gov (NCT 01573962).

Respiratory infections: a current and future threat

Despite all the medical progress in the last 50 years pulmonary infections continue to exact and extremely high human and economic cost. This review will focus on the human, pathogen and environmental factors that contribute to the continued global burden or respiratory diseases with a particular focus on areas where we might hope to see some progress in the coming decades.

Preinfection systemic inflammatory markers and risk of hospitalization due to pneumonia

RATIONALE

Elevated proinflammatory cytokines are associated with severity of pneumonia, but the role of preinfection cytokine levels in the predisposition to pneumonia in humans is less clear.

OBJECTIVE

To ascertain role of preinfection inflammatory markers on susceptibility to community-acquired pneumonia (CAP).

METHODS

Longitudinal analysis over 6.5 yr of a cohort that consisted of 70- to 79-yr-old well-functioning elderly individuals.

MEASUREMENTS

Association between preinfection tumor necrosis factor (TNF), interleukin 6 (IL-6), and C-reactive protein (CRP) levels and CAP requiring hospitalization.

RESULTS

Of the 3,075 participants, 161 (5.2%) developed at least one episode of CAP requiring hospitalization over a median duration of 3.3 yr. The highest tertiles of TNF (> 3.7 pg/ml) and IL-6 (> 2.4 pg/ml) were associated with increased risk of CAP, and the adjusted odds ratios were 1.6 (95% confidence interval [CI], 1.02-2.7) and 1.7 (95% CI, 1.1-2.8), respectively. The adjusted risk of CAP with at least one of these markers in the highest tertile was 1.6 (95% CI, 1.1-2.3). TNF and IL-6 levels in the highest tertile had a synergistic effect (p = 0.01 for interaction), and risk of CAP for both markers in the highest tertile was 2.8 (95% CI, 1.8-4.3). An FEV(1) of 50% or less of predicted was associated with the highest risk of CAP (adjusted odds ratio, 3.6; 95% CI, 2.3-5.6). Furthermore, TNF and IL-6 levels modified risk of CAP in participants with coexisting medical conditions and history of smoking.

CONCLUSION

In the well-functioning elderly subjects, preinfection systemic levels of TNF and IL-6 were associated with higher risk of CAP requiring hospitalization in smokers and those with coexisting medical conditions.

Severe community-acquired pneumonia as a cause of severe sepsis: data from the PROWESS study

OBJECTIVE

To investigate community-acquired pneumonia (CAP) as a cause of severe sepsis in the PROWESS (Recombinant Human Activated Protein C Worldwide Evaluation in Severe Sepsis) trial and to evaluate the effect of drotrecogin alfa (activated) (DrotAA) in this subgroup.

DESIGN

Retrospective analysis of the severe CAP subgroup in the PROWESS trial.

SETTING

Tertiary care institutions in 11 countries.

INTERVENTIONS

DrotAA (n = 850), 24 microg.kg.hr for 96 hrs, or placebo (n = 840).

PARTICIPANTS

The 1,690 patients with severe sepsis enrolled in the PROWESS trial.

MEASUREMENTS AND MAIN RESULTS

Patients were classified as having CAP if lung was the primary site of infection and if they were enrolled directly from home (private residence) with </=4 days in the hospital before receipt of study drug in the PROWESS trial. Survival at 28 days, hospital discharge, and 90 days was compared in DrotAA and placebo groups in the CAP subgroup of PROWESS and CAP subgroups based on disease severity. Of the 1,690 PROWESS patients, 35.6% (DrotAA, n = 324; placebo, n = 278) were classified as severe CAP. Of these severe CAP patients, 26.1% had Streptococcus pneumoniae infections. Within CAP, 79.1% were enrolled by the end of the second calendar day in the hospital, and approximately 90% of CAP patients were at high risk of death according to the Pneumonia Severity Index category. Based on their dependence on vasopressors, 59% of CAP patients were judged at high risk of death. Biomarkers of coagulation and inflammation were markedly abnormal in severe CAP patients. In severe CAP patients treated with DrotAA, a relative risk reduction in mortality of 28% was observed at 28 days, with a relative risk reduction in mortality of 14% observed at 90 days from the start of study drug infusion. The survival benefit was most pronounced in severe CAP patients with S. pneumoniae and in severe CAP patients at high risk of death as indicated by Acute Physiology and Chronic Health Evaluation II score of >/=25, Pneumonia Severity Index score of >/=4, or CURB-65 (confusion, urea, respiratory rate, blood pressure, age) score of >/=3.

CONCLUSIONS

CAP associated with a high Pneumonia Severity Index score, bacteremia, or an intense coagulation and inflammatory response requiring intensive care unit care were indicators of a high risk of death from severe sepsis. In patients with severe sepsis resulting from CAP, a readily identifiable disease, DrotAA, improved survival compared with placebo.

Efficacy and safety of LY315920Na/S-5920, a selective inhibitor of 14-kDa group IIA secretory phospholipase A2, in patients with suspected sepsis and organ failure

OBJECTIVE

Concentrations of group IIA secretory phospholipase A, an inflammatory response mediator, are increased in the plasma of patients with sepsis and septic shock, and the extent of elevation is correlated with mortality. LY315920Na/S-5920 is a selective inhibitor of group IIA secretory phospholipase A that has been shown to inhibit serum group IIA secretory phospholipase A enzyme activity in patients with severe sepsis. The primary objectives of this study were to determine whether there was a dose-response relationship between two doses of LY315920Na/S-5920 compared with placebo in the reduction of 28-day all-cause mortality in patients with severe sepsis and to determine whether LY315920Na/S-5920 had an acceptable safety profile.(2) (2) (2)

DESIGN

Multicenter, double-blind, placebo-controlled trial of two doses of LY315920Na/S-5920 in a parallel design.

PATIENTS

A total of 586 patients with severe sepsis at 72 institutions in the United States. INTERVENTIONS Patients enrolled within 72 hrs from onset of first sepsis-induced organ failure were randomized (1:1:1) to low-dose LY315920Na/S-5920 (target plasma concentration of 200 ng/mL, n = 196), high-dose LY315920Na/S-5920 (800 ng/mL, n = 194), or placebo (n = 196). Study medication was administered as a constant-rate intravenous infusion for 168 hrs.

MEASUREMENTS AND MAIN RESULTS

The study was stopped prematurely because it was unlikely that a statistically significant difference in mortality between LY315920Na/S-5920 and placebo would be found. There was no effect of LY315920Na/S-5920 on the primary end point of 28-day all-cause mortality across the entire study population. The 28-day all-cause mortality was distributed as follows: placebo group, 33.2% (65/196 patients); low-dose LY315920Na/S-5920, 37.2% (73/196); and high-dose LY315920Na/S-5920, 36.1% (70/194); p = .525. However, in a prospectively planned analysis, there was a favorable overall dose-response effect on 28-day all-cause mortality in patients administered LY315920Na/S-5920 within 18 hrs of onset of the first sepsis-induced organ failure. Among these patients, 28-day all-cause mortality was distributed as follows: placebo group, 43.5% (20/46 patients); low-dose LY315920Na/S-5920, 31.4% (16/51); and high-dose LY315920Na/S-5920, 20.8% (10/48); p = .018.

CONCLUSIONS

Administration of LY315920Na/S-5920 had an acceptable safety profile in patients with severe sepsis. There was no overall survival benefit associated with the use of LY315920Na/S-5920 in this study. However, prospectively planned secondary analyses suggested that treatment with LY315920Na/S-5920 was associated with an improvement in survival in patients treated within 18 hrs of the first sepsis-induced organ failure.

Causes of prolonged mechanical ventilation after coronary artery bypass surgery

STUDY OBJECTIVE

To evaluate causes of failure to be extubated (FTE) after coronary artery bypass graft (CABG) surgery.

DESIGN

Prospective observational study.

SETTING

Cardiovascular surgical ICU.

PATIENTS

Four hundred patients undergoing CABG surgery. Following surgery, patients were extubated by a standardized respiratory protocol and were assessed at 8, 24, and 48 h. Patients who could not be extubated at 8 h were designated as FTE, and at 24 and 48 h they were labeled as requiring prolonged mechanical ventilation (PMV) > 24 h and PMV > 48 h, respectively.

MEASUREMENTS AND RESULTS

One hundred sixty-seven patients (41.75%), 27 patients (6.75%), and 21 (5.25%) patients, respectively, could not be extubated at 8, 24, and 48 h. Depressed level of consciousness was the most common reason for FTE in 58 of 167 patients (34.7%). The main cause of depressed level of consciousness was prolonged sedation due to anesthetic agents (51 patients; 30.5%). Hypoxemia was the most common cause for PMV for > 24 h (15 patients) and PMV > 48 h (13 patients). The causes of hypoxemia were cardiogenic and noncardiogenic pulmonary edema, pneumonia, and "hypoxemia of unknown etiology." Tachypnea due to acid-base disturbances was a reason for FTE and PMV for > 24 h in 27 and 3 patients, respectively. Cardiovascular instability was a rare reason for FTE. Postoperative bleeding was a cause for PMV in 18 patients. Four patients had more than a single reason for FTE at each assessment. Different causes have a variable effect on the duration of mechanical ventilation.

CONCLUSION

The causes of PMV are heterogeneous, vary with time, and have a variable impact on the duration of mechanical ventilation required after the patient undergoes CABG surgery.

Validity of scoring systems to predict risk of prolonged mechanical ventilation after coronary artery bypass graft surgery

STUDY OBJECTIVE

Two scoring systems, (the Spivack scoring system [SSS] and the cardiac risk score [CRS]), have been proposed to predict the risk of prolonged mechanical ventilation (PMV) after coronary artery bypass graft surgery (CABG). The primary objective of this study was to validate the efficacy of these scoring systems to predict the risk of PMV.

DESIGN

Prospective observational study.

SETTING

Cardiovascular surgical ICU.

PATIENTS

Three hundred forty-eight patients underwent CABG. Following surgery, patients were extubated by a standardized respiratory weaning protocol.

MEASUREMENTS AND RESULTS

Forty-nine percent of patients had SSS > 0 and had significantly longer duration of mechanical ventilation. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the SSS for failure to extubate at 48 h are 80, 49, 9%, and 98%, respectively. Two hundred thirty-two patients (67.5%), 101 patients (29%), and 12 patients (3.5%) had a CRS of 0 to 4, 5 to 8, and > 8, respectively. Patients with lower scores had shorter duration of mechanical ventilation. The sensitivity, specificity, PPV, and NPV of the CRS for failure to extubate at 10 h are 42, 73, 47% and 69%, respectively.

CONCLUSION

The SSS may be used as a preoperative screening tool. A simple questionnaire that includes history of unstable angina, diabetes, congestive heart failure, and smoking prior to hospital admission can be used to calculate the SSS. Patients with SSS <or= 0 are at low risk for PMV and can proceed to surgery without further evaluation.

Filgrastim in patients with pneumonia and severe sepsis or septic shock

STUDY OBJECTIVES

Evaluate the safety of filgrastim (recombinant methionyl human granulocyte colony-stimulating factor) administration, combined with standard therapy, in patients with pneumonia and either septic shock or severe sepsis who were receiving mechanical ventilation.

DESIGN

Multicenter, double-blind, randomized, placebo-controlled study.

SETTING

ICU, multicenter.

PATIENTS

Eighteen patients with pneumonia and hypotension, or in the absence of shock, two or more end-organ dysfunctions, were enrolled and treated. Baseline acute physiology and chronic health evaluation II scores and median age for the filgrastim (n = 12) and placebo (n = 6) groups were 25.0 and 49.5 years and 31.5 and 56.5 years, respectively.

INTERVENTION

Filgrastim (300 microg) or placebo was administered IV daily for up to 5 days.

MEASUREMENTS AND RESULTS

Study end points included safety; biological response, including endogenous cytokine levels, endotoxin levels, and neutrophil counts; and mortality. Cytokine and endotoxin levels were highly variable in both groups. By day 29, 3 of 12 filgrastim-treated patients and 4 of 6 placebo-treated patients had died. There were no differences in types and occurrences of adverse events, including ARDS, or in outcome between the two groups. Three of four placebo-treated patients had persistent bacterial growth on bronchoscopy repeated after 48 h compared with 2 of 10 filgrastim-treated patients.

CONCLUSION

Filgrastim appeared to be well tolerated in this population of patients with pneumonia and severe sepsis or septic shock. Larger studies to determine the benefit of filgrastim in patients with pneumonia and sepsis or organ dysfunction are warranted.

Linezolid (PNU-100766) versus vancomycin in the treatment of hospitalized patients with nosocomial pneumonia: a randomized, double-blind, multicenter study

Linezolid, the first oxazolidinone, is active against gram-positive bacteria, including multidrug-resistant strains. This multinational, randomized, double-blind, controlled trial compared the efficacy, safety, and tolerability of linezolid with vancomycin in the treatment of nosocomial pneumonia. A total of 203 patients received intravenous linezolid, 600 mg twice daily, plus aztreonam, and 193 patients received vancomycin, 1 g intravenously twice daily, plus aztreonam for 7-21 days. Clinical and microbiological outcomes were evaluated at test of cure 12-28 days after treatment. Clinical cure rates (71 [66.4%] of 107 for linezolid vs. 62 [68.1%] of 91 for vancomycin) and microbiological success rates (36 [67.9%] of 53 vs. 28 [71.8%] of 39, respectively) for evaluable patients were equivalent between treatment groups. Eradication rates of methicillin-resistant Staphylococcus aureus and safety evaluations were similar between treatment groups. Resistance to either treatment was not detected. Linezolid is a well-tolerated, effective treatment for adults with gram-positive nosocomial pneumonia.

Double-blind randomised controlled trial of monoclonal antibody to human tumour necrosis factor in treatment of septic shock. NORASEPT II Study Group

BACKGROUND

Despite the availability of potent antibiotics and intensive care, mortality rates from septic shock are 40-70%. We assessed the safety and efficacy of murine monoclonal antibody to human tumour necrosis factor alpha (TNF alpha MAb) in the treatment of septic shock.

METHODS

In a randomised, multicentre, double-blind, placebo-controlled clinical trial in 105 hospitals in the USA and Canada, we randomly assigned 1879 patients a single infusion of 7.5 mg/kg TNF alpha MAb (n=949) or placebo (0.25% human serum albumin n=930). Our main outcome measurement was the rate of all-cause mortality at 28 days.

FINDINGS

382 (40.3%) of 948 patients who received TNF alpha MAb and 398 (42.8%) of 930 who received placebo had died at 28 days (95% CI -0.02 to 0.07, p=0.27). We found no association between therapy with TNF alpha MAb and increased rapidity in reversal of initial shock or prevention of subsequent shock. Similarly, baseline plasma interleukin-6 concentrations of more than 1000 pg/mL or detectable circulating TNF concentrations were not associated with improvement in survival after TNF alpha MAb therapy. Coagulopathy but not other organ or system failures, was significantly decreased in the TNF alpha MAb group compared with placebo (day 7, p<0.001; day 28, p=0.005). Serious adverse events were reported in 55.2% of patients given placebo and 54.1% in the TNF alpha MAb group.

INTERPRETATION

We did not find an improvement in survival after septic shock with TNF alpha MAb. Therapy not solely dependent on TNF alpha blockade may be required to improve survival.

Noninvasive positive pressure ventilation via face mask. First-line intervention in patients with acute hypercapnic and hypoxemic respiratory failure

OBJECTIVES

We have previously reported our experience with noninvasive positive pressure ventilation (NPPV) via face mask in a small group of selected patients with acute respiratory failure (ARF). NPPV was frequently effective (70% success rate) in correcting gas exchange abnormalities and in avoiding endotracheal intubation (ETI); NPPV also had a low rate of complications. We have evaluated the clinical application of NPPV as first-line intervention in patients with hypercapnic and short-term hypoxemic ARF. A dedicated respiratory therapist conducted an educational program with physicians-in-training rotating through the medical ICUs of a university medical center and supervised implementation of a simplified management protocol. Over 24 months, 164 patients with heterogeneous forms of ARF received NPPV. We report on the effectiveness of NPPV in correcting gas exchange abnormalities, in avoiding ETI, and associated complications, in different conditions precipitating ARF.

PATIENT POPULATION

One hundred fifty-eight patients completed the study. Forty-one had hypoxemic ARF, 52 had hypercapnic ARF, 22 had hypercapnic acute respiratory insufficiency (ARI), 17 had other forms of ARF, and 26 with advanced illness had ARF and refused intubation. Twenty-five percent of the patients developed ARF after extubation.

INTERVENTION

Mechanical ventilation was delivered via a face mask. Initial ventilatory settings were continuous positive airway pressure (CPAP) mode, 5 cm H2O, with pressure support ventilation of 10 to 20 cm H2O titrated to achieve a respiratory rate less than 25 breaths/min and an exhaled tidal volume of 7 mL/kg or more. Ventilator settings were adjusted following arterial blood gases (ABG) results.

RESULTS

The mean duration of NPPV was 25 +/- 24 h. When the 26 patients with advanced illness are excluded, NPPV was effective in improving or correcting gas exchange abnormalities in 105 patients (80%) and avoiding ETI in 86 (65%). Failure to improve ABG values was the reason for ETI in 20 of 46 (43%). The overall average predicted and actual mortality were 32% and 16%, respectively. Survival was 93% in non-intubated patients and 79% in intubated patients. NPPV was effective in lessening dyspnea throughout treatment in all but seven patients. Complications developed in 24 patients (16%). In patients with hypercapnic ARF, nonresponders had a higher PaCO2 at entrance (91.5 +/- 4.2 vs 80 +/- 1.5; p < 0.01). In patients with hypercapnic ARF and ARI, arterial blood gases response (pH and PaCO2) within 2 h of NPPV predicted success (p < 0.0001). None of the entrance parameters predicted need for ETI.

CONCLUSIONS

We conclude that application of NPPV in clinical practice is an effective and safe alternative to ETI in many hemodynamically stable patients with hypercapnic ARF and in those with hypoxemic ARF in whom the clinical condition can be readily reversed in 48 to 72 h. An educational and supervision program is essential to successfully implement this form of therapy.