Adjudicating ventilator-associated pneumonia in a randomized trial of critically ill patients

Adjudication of a primary trial outcome: Results of a calibration exercise and protocol for a large international trial

Background

Ascertainment of the severity of the primary outcome of upper gastrointestinal (GI) bleeding is integral to stress ulcer prophylaxis trials. This protocol outlines the adjudication process for GI bleeding events in an international trial comparing pantoprazole to placebo in critically ill patients (REVISE: Re-Evaluating the Inhibition of Stress Erosions). The primary objective of the adjudication process is to assess episodes submitted by participating sites to determine which fulfil the definition of the primary efficacy outcome of clinically important upper GI bleeding. Secondary objectives are to categorize the bleeding severity if deemed not clinically important, and adjudicate the bleeding site, timing, investigations, and treatments.

Methods

Research coordinators follow patients daily for any suspected clinically important upper GI bleeding, and submit case report forms, doctors' and nurses' notes, laboratory, imaging, and procedural reports to the methods center. An international central adjudication committee reflecting diverse specialty backgrounds conducted an initial calibration exercise to delineate the scope of the adjudication process, review components of the definition, and agree on how each criterion will be considered fulfilled. Henceforth, bleeding events will be stratified by study drug, and randomly assigned to adjudicator pairs (blinded to treatment allocation, and study center).

Results

Crude agreement, chance-corrected agreement, or chance-independent agreement if data have a skewed distribution will be calculated.

Conclusions

Focusing on consistency and accuracy, central independent blinded duplicate adjudication of suspected clinically important upper GI bleeding events will determine which events fulfil the definition of the primary efficacy outcome for this stress ulcer prophylaxis trial.

Registration

NCT03374800 (REVISE: Re-Evaluating the Inhibition of Stress Erosions).

Ceragenin-coated endotracheal tubes for the reduction of ventilator-associated pneumonia: a prospective, longitudinal, cross-over, interrupted time, implementation study protocol (CEASE VAP study)

BACKGROUND

Critically ill patients are at high risk of acquiring ventilator-associated pneumonia (VAP), which occurs in approximately 20% of mechanically ventilated patients. VAP results either from aspiration of pathogen-contaminated oropharyngeal secretions or contaminated biofilms that form on endotracheal tubes (ETTs) after intubation. VAP results in increased duration of mechanical ventilation, increased intensive care unit and hospital length of stay, increased risk of death and increased healthcare costs. Because of its impact on patient outcomes and the healthcare system, VAP is regarded as an important patient safety issue and there is an urgent need for better evidence on the efficacy of prevention strategies. Modified ETTs that reduce aspiration of oropharyngeal secretions with subglottic secretion drainage or reduce the occurrence of biofilm with a coating of ceragenins (CSAs) are available for clinical use in Canada. In this implementation study, we will evaluate the efficacy of these two types of Health Canada-licensed ETTs on the occurrence of VAP, and impact on patient-centred outcomes.

METHODS

In this ongoing, pragmatic, prospective, longitudinal, interrupted time, cross-over implementation study, we will compare the efficacy of a CSA-coated ETT (CeraShield N8 Pharma) with an ETT with subglottic secretion drainage (Taper Guard, Covidien). The study periods consist of four alternating time periods of 11 or 12 weeks or a total of 23 weeks for each ETT. All patients intubated with the study ETT in each time period will be included in an intention-to-treat analysis. Outcomes will include VAP incidence, mortality and health services utilisation including antibiotic use and length of stay.

ETHICS AND DISSEMINATION

This study has been approved by the Health Sciences Research Ethics Board at Queen's University. The results of this study will be actively disseminated through manuscript publication and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05761613.

An Adjudication Protocol for Severe Pneumonia

Background

Clinical end points that constitute successful treatment in severe pneumonia are difficult to ascertain and vulnerable to bias. The utility of a protocolized adjudication procedure to determine meaningful end points in severe pneumonia has not been well described.

Methods

This was a single-center prospective cohort study of patients with severe pneumonia admitted to the medical intensive care unit. The objective was to develop an adjudication protocol for severe bacterial and/or viral pneumonia. Each episode of pneumonia was independently reviewed by 2 pulmonary and critical care physicians. If a discrepancy occurred between the 2 adjudicators, a third adjudicator reviewed the case. If a discrepancy remained after all 3 adjudications, consensus was achieved through committee review.

Results

Evaluation of 784 pneumonia episodes during 593 hospitalizations achieved only 48.1% interobserver agreement between the first 2 adjudicators and 78.8% when agreement was defined as concordance between 2 of 3 adjudicators. Multiple episodes of pneumonia and presence of bacterial/viral coinfection in the initial pneumonia episode were associated with lower interobserver agreement. For an initial episode of bacterial pneumonia, patients with an adjudicated day 7-8 clinical impression of cure (compared with alternative impressions) were more likely to be discharged alive (odds ratio, 6.3; 95% CI, 3.5-11.6).

Conclusions

A comprehensive adjudication protocol to identify clinical end points in severe pneumonia resulted in only moderate interobserver agreement. An adjudicated end point of clinical cure by day 7-8 was associated with more favorable hospital discharge dispositions, suggesting that clinical cure by day 7-8 may be a valid end point to use in adjudication protocols.

French national epidemiology of bacterial superinfections in ventilator-associated pneumonia in patients infected with COVID-19: the COVAP study

BACKGROUND

Description and comparison of bacterial characteristics of ventilator-associated pneumonia (VAP) between critically ill intensive care unit (ICU) patients with COVID-19-positive, COVID + ; and non-COVID-19, COVID-.

METHODS

Retrospective, observational, multicenter study that focused on French patients during the first wave of the pandemic (March-April 2020).

RESULTS

935 patients with identification of at least one bacteriologically proven VAP were included (including 802 COVID +). Among Gram-positive bacteria, S. aureus accounted for more than two-thirds of the bacteria involved, followed by Streptococcaceae and enterococci without difference between clinical groups regarding antibiotic resistance. Among Gram-negative bacteria, Klebsiella spp. was the most frequently observed bacterial genus in both groups, with K. oxytoca overrepresented in the COVID- group (14.3% vs. 5.3%; p < 0.05). Cotrimoxazole-resistant bacteria were over-observed in the COVID + group (18.5% vs. 6.1%; p <0.05), and after stratification for K. pneumoniae (39.6% vs. 0%; p <0.05). In contrast, overrepresentation of aminoglycoside-resistant strains was observed in the COVID- group (20% vs. 13.9%; p < 0.01). Pseudomonas sp. was more frequently isolated from COVID + VAPs (23.9% vs. 16.7%; p <0.01) but in COVID- showed more carbapenem resistance (11.1% vs. 0.8%; p <0.05) and greater resistance to at least two aminoglycosides (11.8% vs. 1.4%; p < 0.05) and to quinolones (53.6% vs. 7.0%; p <0.05). These patients were more frequently infected with multidrug-resistant bacteria than COVID + (40.1% vs. 13.8%; p < 0.01).

CONCLUSIONS

The present study demonstrated that the bacterial epidemiology and antibiotic resistance of VAP in COVID + is different from that of COVID- patients. These features call for further study to tailor antibiotic therapies in VAP patients.

Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness (BALANCE) randomised clinical trial: study protocol

INTRODUCTION

Bloodstream infections are a leading cause of mortality and morbidity; the duration of treatment for these infections is understudied.

METHODS AND ANALYSIS

We will conduct an international, multicentre randomised clinical trial of shorter (7 days) versus longer (14 days) antibiotic treatment among hospitalised patients with bloodstream infections. The trial will include 3626 patients across 60 hospitals and 6 countries. We will include patients with blood cultures confirming a pathogenic bacterium after hospital admission. Exclusion criteria will include patient factors (severe immunosuppression), infection site factors (endocarditis, osteomyelitis, undrained abscesses, infected prosthetic material) and pathogen factors (Staphylococcus aureus, Staphylococcus lugdunensis, Candida and contaminant organisms). We will leave the selection of specific antibiotics, doses and route of delivery to the discretion of treating physicians; no placebo control will be used given the diversity of pathogens and sources of bacteraemia. The intervention will be assignment of treatment duration to be 7 versus 14 days. We will minimise selection bias via central randomisation with variable block sizes, with concealed allocation until day 7 of adequate antibiotic treatment. The primary outcome is 90-day survival; we will test whether 7 days is non-inferior to 14 days of treatment, with a non-inferiority margin of 4% absolute mortality. Secondary outcomes include hospital and intensive care unit (ICU) mortality, relapse rates of bacteraemia, hospital and ICU length of stay, mechanical ventilation and vasopressor duration, antibiotic-free days, Clostridium difficile infection, antibiotic allergy and adverse events and colonisation/infection with antibiotic-resistant organisms.

ETHICS AND DISSEMINATION

The study has been approved by the ethics review board at each participating site. Sunnybrook Health Sciences Centre is the central ethics committee. We will disseminate study results via the Canadian Critical Care Trials Group and other collaborating networks to set the global paradigm for antibiotic treatment duration for non-staphylococcal Gram-positive, Gram-negative and anaerobic bacteraemia, among patients admitted to hospital.

TRIAL REGISTRATION NUMBER

The BALANCE (Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness) trial was registered at www.clinicaltrials.gov (registration number: NCT03005145).

Re-evaluating the Inhibition of Stress Erosions (REVISE): a protocol for pilot randomized controlled trial

INTRODUCTION

Clinicians routinely administer stress ulcer prophylaxis to mechanically ventilated patients in the intensive care unit (ICU), most commonly prescribing proton pump inhibitors (PPIs). However, the incidence of gastrointestinal (GI) bleeding from stress ulceration is low and recent observational studies suggest these agents may increase infections. Therefore, a large randomized clinical trial (RCT) is needed to inform modern practice. The aim of this multicenter pilot trial is to determine the feasibility of performing a large RCT to investigate the efficacy and safety of withholding intravenous pantoprazole.

METHODS AND ANALYSIS

We will include adult critically ill patients who have an anticipated duration of ventilation of >=48 hours. We will exclude patients with acute or recent GI bleeding, pregnancy, dual antiplatelet therapy, poor prognosis or intent to withdraw life support, or previous enrolment in this or a confounding trial. Following informed consent, patients will be randomized to receive the intervention of placebo (0.9% NaCl) or intravenous pantoprazole 40 mg daily. Patients, families, clinicians, data collectors, adjudicators of outcome and statisticians will be blind to allocation. The three primary feasibility outcomes are the informed consent rate, recruitment rate, and protocol adherence. Clinical outcomes include clinically important upper GI bleeding, ventilator-associated pneumonia (VAP), Clostridium difficile infection, length of stay and mortality in ICU and hospital.

ETHICS AND APPROVAL

This study has been approved by Health Canada, and research ethics board (REB) at each of the participating centers.

TRIAL REGISTRATION NUMBER

This trial was registered on 31 October 2014. The trial registration number is NCT02290327.

FUNDING

REVISE Pilot Trial is funded by Research Grant awarded by Physicians Services Incorporated, Dammam University Research Funds, Capital Health Authority Research Award Halifax, and Royal Adelaide Hospital Project Committee Grant.

Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness (BALANCE): study protocol for a pilot randomized controlled trial

Background

Bacteremia is a leading cause of mortality and morbidity in critically ill adults. No previous randomized controlled trials have directly compared shorter versus longer durations of antimicrobial treatment in these patients.

Methods/Design

This is a multicenter pilot randomized controlled trial in critically ill patients with bacteremia. Eligible patients will be adults with a positive blood culture with pathogenic bacteria identified while in the intensive care unit. Eligible, consented patients will be randomized to either 7 days or 14 days of adequate antimicrobial treatment for the causative pathogen(s) detected on blood cultures. The diversity of pathogens and treatment regimens precludes blinding of patient and clinicians, but allocation concealment will be extended to day 7 and outcome adjudicators will be blinded. The primary outcome for the main trial will be 90-day mortality. The primary outcome for the pilot trial is feasibility defined by (i) rate of recruitment exceeding 1 patient per site per month and (ii) adherence to treatment duration protocol ≥ 90%. Secondary outcomes include intensive care unit, hospital and 90-day mortality rates, relapse rates of bacteremia, antibiotic-related side effects and adverse events, rates of Clostridium difficile infection, rates of secondary infection or colonization with antimicrobial resistant organisms, ICU and hospital lengths of stay, mechanical ventilation and vasopressor duration in intensive care unit, and procalcitonin levels on the day of randomization, and day 7, 10 and 14 after the index blood culture.

Discussion

The BALANCE pilot trial will inform the design and execution of the subsequent BALANCE main trial, which will evaluate shorter versus longer duration treatment for bacteremia in critically ill patients, and thereby provide an evidence basis for treatment duration decisions for these infections.

Trial registration

The Pilot Trial was registered on 26 September 2014. Trial registration number: NCT02261506.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-015-0688-z) contains supplementary material, which is available to authorized users.

Design and execution of clinical trials in orthopaedic surgery

High-quality randomised controlled trials (RCTs) evaluating surgical therapies are fundamental to the delivery of evidence-based orthopaedics. Orthopaedic clinical trials have unique challenges; however, when these challenges are overcome, evidence from trials can be definitive in its impact on surgical practice. In this review, we highlight several issues that pose potential challenges to orthopaedic investigators aiming to perform surgical randomised controlled trials. We begin with a discussion on trial design issues, including the ethics of sham surgery, the importance of sample size, the need for patient-important outcomes, and overcoming expertise bias. We then explore features surrounding the execution of surgical randomised trials, including ethics review boards, the importance of organisational frameworks, and obtaining adequate funding. Cite this article: Bone Joint Res 2014;3:161-8.

Adjudication of bleeding outcomes in an international thromboprophylaxis trial in critical illness

INTRODUCTION

Measuring bleeding in critical care trials is challenging. We determined the reliability of adjudicated bleeding assessments in a large thromboprophylaxis trial in the intensive care unit (ICU).

MATERIALS AND METHODS

PROphylaxis for ThromboEmbolism in Critical Care Trial (PROTECT) was an international randomized controlled trial that compared dalteparin to unfractionated heparin for the prevention of deep vein thrombosis in the ICU. Daily bleeding data were collected prospectively using a validated tool. Bleeds were adjudicated in duplicate by 2 of 4 members comprising a central adjudication committee. Bleeds were stratified by severity and study drug, then randomly assigned to adjudicator pairs. Adjudicators were blinded to treatment allocation, study centre and peer-assessments. We calculated agreement on bleeding severity and examined the effect of adjudication on overall trial results.

RESULTS

In PROTECT, 491 patients had bleeding events including 208 with major bleeding and 283 with minor bleeding only. Of 491 patients, 446 were adjudicated in duplicate: 182 with major, 250 with minor and 14 with no bleeding. After adjudication, 52 of 244 bleeds were downgraded to minor; whereas only 15 of 244 were upgraded to major. Overall agreement among adjudicators was excellent (crude agreement=86.3%; kappa=0.76). Hazard ratios for major or any bleeding with dalteparin or unfractionated heparin were similar when analyzed using non-adjudicated events.

CONCLUSIONS

Major bleeds were sometimes over-called by research coordinators in a large ICU thromboprohylaxis trial. Adjudicator agreement was excellent. Central adjudication allowed reliable bleeding assessment and enhanced the rigor and validity of this major safety outcome.

Prospective evaluation of sedation-related adverse events in pediatric patients ventilated for acute respiratory failure

OBJECTIVES

Sedation-related adverse events in critically ill pediatric patients lack reproducible operational definitions and reference standards. Understanding these adverse events is essential to improving the quality of patient care and for developing prevention strategies in critically ill children. The purpose of this study was to test operational definitions and estimate the rate and site-to-site heterogeneity of sedation-related adverse events.

DESIGN

Prospective cohort study.

SETTING

Twenty-two pediatric intensive care units in the United States enrolling baseline patients into a prerandomization phase of a multicenter trial on sedation management.

PATIENTS

Pediatric patients intubated and mechanically ventilated for acute respiratory failure.

DATA EXTRACTION

Analysis of adverse event data using consistent operational definitions from a Web-based data management system.

MEASUREMENTS AND MAIN RESULTS

There were 594 sedation-related adverse events reported in 308 subjects, for a rate of 1.9 adverse events per subject and 16.6 adverse events per 100 pediatric intensive care unit days. Fifty-four percent of subjects had at least one adverse event. Seven (1%) adverse events were classified as severe, 347 (58%) as moderate, and 240 (40%) as mild. Agitation (30% of subjects, 41% of events) and pain (27% of subjects, 29% of events) were the most frequently reported events. Eight percent of subjects (n = 24) experienced 54 episodes of clinically significant iatrogenic withdrawal. Unplanned endotracheal tube extubation occurred at a rate of 0.82 per 100 ventilator days, and 32 subjects experienced postextubation stridor. Adverse events with moderate intraclass correlation coefficients included: Inadequate sedation management (intraclass correlation coefficient = 0.130), clinically significant iatrogenic withdrawal (intraclass correlation coefficient = 0.088), inadequate pain management (intraclass correlation coefficient = 0.080), and postextubation stridor (intraclass correlation coefficient = 0.078).

CONCLUSIONS

Operational definitions for sedation-related adverse events were consistently applied across multiple pediatric intensive care units. Adverse event rates were different from what has been previously reported in single-center studies. Many adverse events have moderate intraclass correlation coefficients, signaling site-to-site heterogeneity.

The dilemma of assessment bias in infection control research

Infection control studies often rely on infection endpoints to determine whether interventions are effective. However, many infection outcomes, including those defined by standardized surveillance criteria, involve some subjective judgment for determination. Studies that use unblinded ascertainment of subjective infection endpoints are at risk of assessment bias. Unfortunately, infection control studies have not routinely accounted for assessment bias. To ensure validity, infection control studies should incorporate study design elements to control assessment bias, such as blinded assessment or use of objective outcome measures.

Adjudicating bleeding events in a platelet dose study: impact on outcome results and challenges

BACKGROUND

In the SToP platelet dose study, the World Health Organization (WHO) bleeding grade was assigned using adjudication. This study describes the challenges associated with adjudicating bleeding events and compares the adjudicated and bedside results for bleeding grade.

STUDY DESIGN AND METHODS

To categorize bleeding, the following information was provided to adjudicators: daily bleeding assessments, interventions to stop or control bleeding, daily blood counts, and transfused blood components. Each daily assessment was sent to two adjudicators who independently assigned a grade and anatomic site of bleeding. Discordant cases where disagreement occurred were sent to a third adjudicator and subsequently to a fourth or fifth adjudicator in an attempt to reach agreement. Disagreement after five adjudicators was resolved by consensus. The final adjudicated grade was compared with the grade of bleeding assigned at the bedside by study personnel.

RESULTS

A total of 1150 case report forms were adjudicated. Disagreement on grade of bleeding was common: 31.2% after the first two adjudicators, 4.0% after the third adjudicator, 0.7% after four, and 0.05% after five. Disagreement on anatomic site was less but still occurred in 17% of cases after two adjudicators. The frequency of bleeding (≥ Grade 2) based on adjudication was higher than bedside grading (standard-dose arm, 47.5% vs. 34.4%; low-dose arm, 50.0% vs. 43.1%).

CONCLUSION

The frequency of WHO bleeding varies depending on the method used to assign grade. Adjudication to assign bleeding grade resulted in significant disagreement when two adjudicators were used.

When is a fracture healed? Radiographic and clinical criteria revisited

Selecting the most appropriate outcome measures can be especially burdensome in trials studying fracture healing, because the process of fracture healing is subjective and without a gold standard. Although a wide variety of radiographic modalities are available, plain radiography remains the most common approach for healing assessment. Radiographic criteria, however, do not correlate well with fracture strength and stiffness. Additional challenges include a lack of consensus in what radiographic measures are most appropriate in the assessment of healing. In this article, we provide an overview of the most commonly used radiographic and clinical criteria for defining fracture healing. The validity and reliability of alternative approaches is also discussed.

Is There a Benefit to Multidisciplinary Rounds in an Open Trauma Intensive Care Unit regarding Ventilator-Associated Pneumonia?

Multidisciplinary rounds (MDRs) have been instituted for patient care since June 2005. Before June 2005, all care was provided by individual practitioners. MDRs include the surgical intensivist, surgical resident, patient's nurse, case manager, pharmacist, chaplain, nutritionist, and respiratory therapist. Our study examined the effect of MDRs on ventilator-associated pneumonia in trauma patients in open intensive care units (ICUs). Group 1 included patients from June 2003 to May 2005 before the implementation of MDRs, and Group 2 included patients after the institution of MDRs from June 2005 to May 2007. In Group 1, there were 83 ventilator-associated pneumonias (VAPs) during 2414 ventilator days. In Group 2, there were 49 VAPs during 2094 ventilator days. The ratio of VAPs per thousand ventilator days decreased from 34.4 to 23.4 between the two groups ( P = 0.04). When comparing trauma patients in our open ICU with similar mean Injury Severity Score and mean Abbreviated Injury Score for chest and for head and neck, implementing MDRs significantly decreased our incidence of VAP.

Event adjudication and data monitoring in an intensive care unit observational study of thromboprophylaxis

BACKGROUND

The objective of this report is to describe the roles, responsibilities and recommendations of a 3-member Event Adjudication Committee (EAC) and a 5-member data monitoring committee (DMC) for a prospective multicenter observational study of critically ill patients with renal insufficiency examining the bioaccumulation and bleeding risk associated with dalteparin thromboprophylaxis.

METHODS

The EAC reviewed bleeding events to adjudicate whether they were major or minor and whether they were related to dalteparin (uncertain, unlikely, or likely). The DMC reviewed all bleeds deemed by the EAC as uncertain or likely due to dalteparin then recommended either to continue or suspend enrolment pending review by the steering committee, or requested more information.

RESULTS

Consensus on bleeding severity was achieved for all cases. At the second planned interim analysis, the EAC recommended to the DMC and steering committee that the EAC should stop adjudicating whether bleeding was related to dalteparin since attribution was challenging in this population with numerous bleeding risk factors; moreover, no bleeding rates were available from prior studies or historical or concurrent controls.

CONCLUSIONS

Adjudication of whether an outcome can be attributed to an intervention in an open-label, uncontrolled observational study gives a potentially misleading impression of research oversight without methodological face validity. In this study, the EAC recommended modification of the adjudication process, and the DMC recommended continuing enrolment to achieve the target sample size.

Better infrastructure for critical care trials: nomenclature, etymology, and informatics

OBJECTIVE

The goals of this review article are to review the importance and value of standardized definitions in clinical research, as well as to propose the necessary tools and infrastructure needed to advance nosology and medial taxonomy to improve the quality of clinical trials in the field of critical care.

DATA SOURCES

We searched MEDLINE for relevant articles, reviewed those selected and their reference lists, and consulted personal files for relevant information.

DATA SYNTHESIS

When the pathobiology of diseases is well understood, standard disease definitions can be extremely specific and precise; however, when the pathobiology of the disease is less well understood or more complex, biological markers may not be diagnostically useful or even available. In these cases, syndromic definitions effectively classify and group illnesses with similar symptoms and clinical signs. There is no clear gold standard for the diagnosis of many clinical entities in the intensive care unit, including notably both acute respiratory distress syndrome and sepsis. There are several types of consensus methods that can be used to explicate the judgmental approach that is often needed in these cases, including interactive or consensus groups, the nominal group technique, and the Delphi technique. Ideally, the definition development process will create clear and unambiguous language in which each definition accurately reflects the current understanding of the disease state.

CONCLUSIONS

The development, implementation, evaluation, revision, and reevaluation of standardized definitions are keys for advancing the quality of clinical trials in the critical care arena.

Strategies to prevent ventilator-associated pneumonia in acute care hospitals

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections. The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing their ventilator-associated pneumonia (VAP) prevention efforts. Refer to the Society for Healthcare Epidemiology of America/Infectious Diseases Society of America “Compendium of Strategies to Prevent Healthcare-Associated Infections” Executive Summary and Introduction and accompanying editorial for additional discussion.

1. Occurrence of VAP in acute care facilities.

a. VAP is one of the most common infections acquired by adults and children in intensive care units (ICUs).

i. In early studies, it was reported that 10%-20% of patients undergoing ventilation developed VAP. More-recent publications report rates of VAP that range from 1 to 4 cases per 1,000 ventilator-days, but rates may exceed 10 cases per 1,000 ventilator-days in some neonatal and surgical patient populations. The results of recent quality improvement initiatives, however, suggest that many cases of VAP might be prevented by careful attention to the process of care.

2. Outcomes associated with VAP

a. VAP is a cause of significant patient morbidity and mortality, increased utilization of healthcare resources, and excess cost.

i. The mortality attributable to VAP may exceed 10%.

ii. Patients with VAP require prolonged periods of mechanical ventilation, extended hospitalizations, excess use of antimicrobial medications, and increased direct medical costs.

Burden of illness in venous thromboembolism in critical care: a multicenter observational study

PURPOSE

The frequency of clinically diagnosed venous thromboembolism (VTE) including deep venous thrombosis (DVT) and pulmonary embolism (PE) in medical-surgical critically ill patients is unclear. The objectives of this study were to estimate the prevalence and incidence of radiologically confirmed DVT and PE in medical-surgical intensive care unit (ICU) patients and to determine the impact of prophylaxis on the frequency of these events.

MATERIALS AND METHODS

In a retrospective observational cohort study in 12 adult ICUs, we identified prevalent cases (diagnosed in the 24 hours preceding ICU admission up to 48 hours post-ICU admission) and incident cases (diagnosed 48 hours or more after ICU admission and up to 8 weeks after ICU discharge) of upper or lower limb DVT or PE. Deep venous thrombosis was diagnosed by compression ultrasound or venogram. Each DVT was classified as clinically suspected or not clinically suspected in that the latter was diagnosed by scheduled screening ultrasonography. Pulmonary embolism was diagnosed by ventilation-perfusion lung scan, computed tomography pulmonary angiography, echocardiography, electrocardiography, or autopsy.

RESULTS

Among 12,338 patients, 252 (2.0%) patients had radiologically confirmed DVT or PE and another 47 (0.4%) had possible DVT or PE. Prevalent DVTs were diagnosed in 0.4% (95% confidence interval [CI], 0.3%-0.5%) of patients and prevalent PEs were diagnosed in 0.4% (95% CI, 0.3%-0.6%). Incident DVTs were diagnosed in 1.0% (95% CI, 0.8%-1.2%) of patients, and incident PEs were diagnosed in 0.5% (95% CI, 0.4%-0.6%). Of patients with incident VTE, 65.8% of cases occurred despite receipt of thromboprophylaxis for at least 80% of their days in ICU. The median (interquartile range) ICU length of stay was similar for patients with DVT (7 [3-17]) and PE (5 [2-8]). For all patients with VTE, ICU mortality was 16.7% (95% CI, 12.0%-21.3%) and hospital mortality was 28.5% (95% CI, 22.8%-34.1%).

CONCLUSIONS

Venous thromboembolism appears to be an apparently infrequent, but likely underdiagnosed problem, occurring among patients receiving prophylaxis. Findings suggest the need for increased suspicion among clinicians, renewed efforts at thromboprophylaxis, and evaluation of superior prevention strategies.

Classification of outcomes events in the Dutch TIA trial: prognostic value of accepted and rejected events

OBJECTIVE

In large multicentre clinical trials adjudication of outcome events most often is done centrally. Some of these events would eventually be judged not to meet the criteria and hence would be rejected. If the classification procedures work correctly one would expect a higher risk of future vascular events after an 'accepted' rather than after a 'rejected event. In the present study we aimed at testing the adequacy of a classification procedure in a trial of patients with a transient ischemic attack (TIA) or minor ischemic stroke by comparing the further outcome between patients in whom a possible event was either rejected or accepted for the final analysis in this trial.

RESEARCH DESIGN AND METHODS

The vascular outcome events were analysed in 3150 patients with TIA or minor stroke who participated in the Dutch TIA trial. We identified the patients with a first 'accepted' or 'rejected' non-fatal stroke or myocardial infarction (MI). In these two groups of patients we determined the occurrence of the subsequent vascular events (vascular death, stroke or MI). The incidence was compared with survival analysis techniques.

RESULTS

Among 308 patients with a first nonfatal 'accepted' event in 81 (26.3%) a new vascular event occurred; among the 51 patients with a 'rejected' event there were 12 (23.5%) such events. The hazard ratio for new vascular events was 1.22 (95% CI 0.67-2.22). After multivariate adjustment for age, type of qualifying event, history of smoking, angina pectoris and myocardial infarction, and Rankin score > or = 3, the hazard ratio was 1.49 (95% CI 0.78-2.84).

CONCLUSION

our study suggested that the adjudication process of outcome events in the Dutch TIA trial was done correctly because a trend towards a higher recurrence rate of vascular events among patients with 'accepted' outcome events was found.

Multicenter clinical research in adult critical care

OBJECTIVE

To describe the development, organization, and operation of several collaborative groups conducting investigator-initiated multicenter clinical research in adult critical care.

DESIGN

To review the process by which investigator-initiated critical care clinical research groups were created using examples from Europe, Australia, the United States, and Canada. Various models of group structure and function are discussed, highlighting complementary approaches to protocol development, multicenter study management, and project funding.

DATA SOURCES

Published peer review research and unpublished terms of reference documents on the structure and function of these groups.

DATA SYNTHESIS

The overall goal of clinical critical care research groups engaged in multicenter studies is to improve patient outcomes through conducting large, rigorous investigations. Research programs we reviewed included the following: a) multicenter epidemiologic studies and surveys; b) technology evaluations of mechanical ventilation; c) investigations focused on three priority fields (acute lung injury, infection, and acute brain injury); d) a series of randomized trials of treatments for one syndrome (acute respiratory distress syndrome); and e) diverse methodologies addressing several clinical problems. The structure and function of these research groups differ according to their historical development, research culture, and enabling resources. Specific protocols emerge from clinical questions generated by investigators or from collectively prioritized research agendas. Project funding includes government support, peer-review grants, intensive care foundations, industry, local hospital funds, and hybrid models. Infrastructure for study management varies widely.

CONCLUSIONS

Several national and international groups have engaged in investigator-initiated multicenter critical care research. The development, organization, and operational methods of these groups illustrate several collaborative models for clinical investigations in the intensive care unit. Common characteristics of these groups are a cohesive spirit, a sense of mission to achieve shared research goals, and acknowledgment that such an organization is much more than the sum of its parts.

Multicenter, prospective, randomized, single-blind study comparing the efficacy and gastrointestinal complications of early jejunal feeding with early gastric feeding in critically ill patients

OBJECTIVE

To compare the incidence of enteral nutrition-related gastrointestinal complications, the efficacy of diet administration, and the incidence of nosocomial pneumonia in patients fed in the stomach or in the jejunum.

DESIGN

Prospective, randomized multicenter study.

SETTING

Intensive care units (ICUs) in 11 teaching hospitals.

PATIENTS

Critically ill patients who could receive early enteral nutrition more than 5 days.

INTERVENTIONS

Enteral nutrition was started in the first 36 hrs after admission. One group was fed with a nasogastric tube (GEN group) and the other in the jejunum through a dual-lumen nasogastrojejunal tube (JEN group).

MEASUREMENTS AND MAIN RESULTS

Gastrointestinal complications were previously defined. The efficacy of diet administration was calculated using the volume ratio (expressed as the ratio between administered and prescribed volumes). Nosocomial pneumonia was defined according the Centers for Disease Control and Prevention's definitions. One hundred ten patients were included (GEN: 51, JEN: 50). Both groups were comparable in age, gender, Acute Physiology and Chronic Health Evaluation II, and Multiple Organ Dysfunction Score. There were no differences in feeding duration, ICU length of stay, or mortality (43% vs. 38%). The JEN group had lesser gastrointestinal complications (57% vs. 24%, p <.001), mainly because of a lesser incidence of increased gastric residuals (49% vs. 2%, p <.001). Volume ratio was similar in both groups. A post hoc analysis showed that the JEN group had a higher volume ratio at day 7 than the GEN group (68% vs. 82%, p <.03) in patients from ICUs with previous experience in jejunal feeding. Both groups had a similar incidence of nosocomial pneumonia (40% vs. 32%).

CONCLUSIONS

Gastrointestinal complications are less frequent in ICU patients fed in the jejunum. Nevertheless, it seems to be a necessary learning curve to achieve better results with a postpyloric access. Early enteral nutrition using a nasojejunal route seems not to be an efficacious measure to decrease nosocomial pneumonia in critically ill patients.

Use of a screen log to audit patient recruitment into multiple randomized trials in the intensive care unit. Canadian Critical Care Trials Group

OBJECTIVE

To develop and evaluate a screen log for monitoring enrollment in multiple randomized clinical trials conducted in a single center.

SETTING

University-affiliated 20-bed tertiary care medical-surgical intensive care unit (ICU).

PATIENTS

Consecutive ICU patients admitted between April 1995 and March 1997.

METHODS

We developed a screen log for multicentered studies conducted in our ICU. Using a multiple-project, unicenter perspective, we evaluated the screen log as a tool for monitoring eligibility and enrollment of patients in four multicentered randomized trials focused on stress ulcer prophylaxis, blood transfusion thresholds, immunotherapy for sepsis and mechanical ventilation strategies.

RESULTS

The screen log was used as an instrument to monitor trial execution. We recorded all aspects of study enrollment and created a taxonomy of reasons for nonenrollment into each trial. We calculated enrollment efficiency rates and used these data to develop strategies to maximize accrual. The screen log became a communication tool that fostered research-oriented continuous quality improvement initiatives for the management of concurrently conducted randomized trials in our ICU.

CONCLUSIONS

Intensivists participating in several clinical trials may be interested in monitoring and maximizing enrollment when conducting multiple studies and understanding the influence of each trial on enrollment into the others. The unicenter, multiple-project screen log is one tool that may help to achieve these goals.