Critical Care Cycling to Improve Lower Extremity Strength (CYCLE): protocol for an international, multicentre randomised clinical trial of early in-bed cycling for mechanically ventilated patients.

INTRODUCTION: In-bed leg cycling with critically ill patients is a promising intervention aimed at minimising immobility, thus improving physical function following intensive care unit (ICU) discharge. We previously completed a pilot randomised controlled trial (RCT) which supported the feasibility of a large RCT. In this report, we describe the protocol for an international, multicentre RCT to determine the effectiveness of early in-bed cycling versus routine physiotherapy (PT) in critically ill, mechanically ventilated adults. METHODS AND ANALYSIS: We report a parallel group RCT of 360 patients in 17 medical-surgical ICUs and three countries. We include adults (≥18 years old), who could ambulate independently before their critical illness (with or without a gait aid), ≤4 days of invasive mechanical ventilation and ≤7 days ICU length of stay, and an expected additional 2-day ICU stay, and who do not fulfil any of the exclusion criteria. After obtaining informed consent, patients are randomised using a web-based, centralised system to either 30 min of in-bed cycling in addition to routine PT, 5 days per week, up to 28 days maximum, or routine PT alone. The primary outcome is the Physical Function ICU Test-scored (PFIT-s) at 3 days post-ICU discharge measured by assessors blinded to treatment allocation. Participants, ICU clinicians and research coordinators are not blinded to group assignment. Our sample size estimate was based on the identification of a 1-point mean difference in PFIT-s between groups. ETHICS AND DISSEMINATION: Critical Care Cycling to improve Lower Extremity (CYCLE) is approved by the Research Ethics Boards of all participating centres and Clinical Trials Ontario (Project 1345). We will disseminate trial results through publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT03471247 (Full RCT); NCT02377830 (CYCLE Vanguard 46 patient internal pilot).

Definitions, rates and associated mortality of ICU-acquired pneumonia: A multicenter cohort study.

INTRODUCTION: We aimed to analyze intensive care unit (ICU)-acquired pneumonia according to 7 definitions, estimating associated hospital mortality. METHODS: This cohort study was nested within an international randomized trial, evaluating the effect of probiotics on ICU-acquired pneumonia in 2650 mechanically ventilated adults. Each clinically suspected pneumonia was adjudicated by two physicians blinded to allocation and center. The primary outcome was ventilator-associated pneumonia (VAP) informed by ventilation for ≥2 days, new, progressive or persistent infiltrate plus 2 of: temperature > 38 °C or < 36 °C; leukopenia (<3 × 10(Fernando et al., 20206)/L) or leukocytosis (>10 × 10(Fernando et al., 20206)/L); and purulent sputum. We also used 6 other definitions estimating the risk of hospital mortality. RESULTS: The frequency of ICU-acquired pneumonia varied by definition: the trial primary outcome VAP (21.6%), Clinical Pulmonary Infection Score (CPIS) (24.9%), American College Chest Physicians (ACCP) (25.0%), International Sepsis Forum (ISF) (24.4%), Reducing Oxidative Stress Study (REDOXS) (17.6%), Centers for Disease Control (CDC) (7.8%), and invasively microbiologically confirmed (1.9%). The trial primary outcome VAP (HR 1.31 [1.08, 1.60]), ISF (HR 1.32 [1.09,1.60]), CPIS (HR 1.30 [1.08,1.58]) and ACCP definitions (HR 1.22 [1.00,1.47]) were associated with hospital mortality. CONCLUSIONS: Rates of ICU-acquired pneumonia vary by definition and are associated with differential increased risk of death.

Dexmedetomidine vs other sedatives in critically ill mechanically ventilated adults: a systematic review and meta-analysis of randomized trials.

Conventional gabaminergic sedatives such as benzodiazepines and propofol are commonly used in mechanically ventilated patients in the intensive care unit (ICU). Dexmedetomidine is an alternative sedative that may achieve lighter sedation, reduce delirium, and provide analgesia. Our objective was to perform a comprehensive systematic review summarizing the large body of evidence, determining if dexmedetomidine reduces delirium compared to conventional sedatives. We searched MEDLINE, EMBASE, CENTRAL, ClinicalTrials.gov and the WHO ICTRP from inception to October 2021. Independent pairs of reviewers identified randomized clinical trials comparing dexmedetomidine to other sedatives for mechanically ventilated adults in the ICU. We conducted meta-analyses using random-effects models. The results were reported as relative risks (RRs) for binary outcomes and mean differences (MDs) for continuous outcomes, with corresponding 95% confidence intervals (CIs). In total, 77 randomized trials (n = 11,997) were included. Compared to other sedatives, dexmedetomidine reduced the risk of delirium (RR 0.67, 95% CI 0.55 to 0.81; moderate certainty), the duration of mechanical ventilation (MD - 1.8 h, 95% CI - 2.89 to - 0.71; low certainty), and ICU length of stay (MD - 0.32 days, 95% CI - 0.42 to - 0.22; low certainty). Dexmedetomidine use increased the risk of bradycardia (RR 2.39, 95% CI 1.82 to 3.13; moderate certainty) and hypotension (RR 1.32, 95% CI 1.07 to 1.63; low certainty). In mechanically ventilated adults, the use of dexmedetomidine compared to other sedatives, resulted in a lower risk of delirium, and a modest reduction in duration of mechanical ventilation and ICU stay, but increased the risks of bradycardia and hypotension.

Diarrhea during critical illness: a multicenter cohort study.

PURPOSE: To study the incidence, predictors, and outcomes of diarrhea during the stay in the intensive care unit (ICU). METHODS: Prospective cohort of consecutive adults in the ICU for > 24 h during a 10-week period across 12 intensive care units (ICUs) internationally. The explored outcomes were: (1) incidence of diarrhea, (2) Clostridioides difficile-associated diarrhea (CDAD); (3) ICU and hospital length of stay (LOS) and mortality in patients with diarrhea. We fit generalized linear models to evaluate the predictors, management, morbidity and mortality associated with diarrhea. RESULTS: Among 1109 patients aged 61.4 (17.5) [mean (standard deviation)] years, 981(88.5%) were medical and 645 (58.2%) were mechanically ventilated. The incidence was 73.8% (818 patients, 73.8%, 95% confidence interval [CI] 71.1-76.6) using the definition of the World Health Organisation (WHO). Incidence varied across definitions (Bristol 53.5%, 95% CI 50.4-56.7; Bliss 37.7%, 95% CI 34.9-40.4). Of 99 patients with diarrhea undergoing CDAD testing, 23 tested positive (2.2% incidence, 95% CI 1.5-3.4). Independent predictors included enteral nutrition (RR 1.23, 95% CI 1.16-1.31, p < 0.001), antibiotic days (RR 1.02, 95% CI 1.02-1.03, p < 0.001), and suppositories (RR 1.14 95% CI 1.06-1.22, p < 0.001). Opiates decreased diarrhea risk (RR 0.76, 95% CI 0.68-0.86, p < 0.001). Diarrhea prompted management modifications (altered enteral nutrition or medications: RR 10.25, 95% CI 5.14-20.45, p < 0.001) or other consequences (fecal management device or CDAD testing: RR 6.16, 95% CI 3.4-11.17, p < 0.001). Diarrhea was associated with a longer time to discharge for ICU or hospital stay, but was not associated with hospital mortality. CONCLUSION: Diarrhea is common, has several predictors, and prompts changes in patient care, is associated with longer time to discharge but not mortality.

Effect of Probiotics on Incident Ventilator-Associated Pneumonia in Critically Ill Patients: A Randomized Clinical Trial.

Importance: Growing interest in microbial dysbiosis during critical illness has raised questions about the therapeutic potential of microbiome modification with probiotics. Prior randomized trials in this population suggest that probiotics reduce infection, particularly ventilator-associated pneumonia (VAP), although probiotic-associated infections have also been reported. Objective: To evaluate the effect of Lactobacillus rhamnosus GG on preventing VAP, additional infections, and other clinically important outcomes in the intensive care unit (ICU). Design, Setting, and Participants: Randomized placebo-controlled trial in 44 ICUs in Canada, the United States, and Saudi Arabia enrolling adults predicted to require mechanical ventilation for at least 72 hours. A total of 2653 patients were enrolled from October 2013 to March 2019 (final follow-up, October 2020). Interventions: Enteral L rhamnosus GG (1 × 1010 colony-forming units) (n = 1321) or placebo (n = 1332) twice daily in the ICU. Main Outcomes and Measures: The primary outcome was VAP determined by duplicate blinded central adjudication. Secondary outcomes were other ICU-acquired infections including Clostridioides difficile infection, diarrhea, antimicrobial use, ICU and hospital length of stay, and mortality. Results: Among 2653 randomized patients (mean age, 59.8 years [SD], 16.5 years), 2650 (99.9%) completed the trial (mean age, 59.8 years [SD], 16.5 years; 1063 women [40.1%.] with a mean Acute Physiology and Chronic Health Evaluation II score of 22.0 (SD, 7.8) and received the study product for a median of 9 days (IQR, 5-15 days). VAP developed among 289 of 1318 patients (21.9%) receiving probiotics vs 284 of 1332 controls (21.3%; hazard ratio [HR], 1.03 (95% CI, 0.87-1.22; P = .73, absolute difference, 0.6%, 95% CI, -2.5% to 3.7%). None of the 20 prespecified secondary outcomes, including other ICU-acquired infections, diarrhea, antimicrobial use, mortality, or length of stay showed a significant difference. Fifteen patients (1.1%) receiving probiotics vs 1 (0.1%) in the control group experienced the adverse event of L rhamnosus in a sterile site or the sole or predominant organism in a nonsterile site (odds ratio, 14.02; 95% CI, 1.79-109.58; P < .001). Conclusions and Relevance: Among critically ill patients requiring mechanical ventilation, administration of the probiotic L rhamnosus GG compared with placebo, resulted in no significant difference in the development of ventilator-associated pneumonia. These findings do not support the use of L rhamnosus GG in critically ill patients. Trial Registration: ClinicalTrials.gov Identifier: NCT02462590.

The cuff leak test in critically ill patients: An international survey of intensivists.

BACKGROUND: The cuff leak test (CLT) is used to assess laryngeal edema prior to extubation. There is limited evidence for its diagnostic accuracy and conflicting guidelines surrounding its use in critically ill patients who do not have risk factors for laryngeal edema. The primary study aim was to describe intensivists' beliefs, attitudes, and practice regarding the use of the CLT. METHODS: A 13-item survey was developed, pilot-tested, and subjected to clinical sensibility testing. The survey was distributed electronically through MetaClinician®. Descriptive statistics and multivariable regression analysis were performed to examine associations between participant demographics and survey responses. RESULTS: 1184 practicing intensivists from 17 countries in North and South America, Europe, Oceania, and Asia participated. The majority (59%) of respondents reported rarely or never perform the CLT prior to extubating patients not at high risk of laryngeal edema, which correlated with 54% of respondents reporting they believed a failed CLT did not predict reintubation. Intensivists from the Middle East were 2.4 times more likely to request a CLT compared to those from North America. Intensivists with base training in medicine or emergency medicine were more likely to request a CLT prior to extubation compared to those with base training in anesthesiology. CONCLUSION: Use of the CLT prior to extubating patients not at high risk of laryngeal edema in the intensive care unit is highly variable. Practice appears to be influenced by country of practice and base specialty training.

End-of-Life Skills and Professionalism for Critical Care Residents in Training: The ESPRIT Survey.

End-of-life (EOL) care is a key aspect of critical care medicine (CCM) training. The goal of this study was to survey CCM residents and program directors (PDs) across Canada to describe current EOL care education. Using a literature review, we created a self-administered survey encompassing 10 CCM national objectives of training to address: (1) curricular content and evaluation methods, (2) residents' preparedness to meet these objectives, and (3) opportunities for educational improvement. We performed pilot testing and clinical sensibility testing, then distributed it to all residents and PDs across the 13 Canadian CCM programs. Our response rate was 84.3% overall (77 [81.1%] for residents and 13 [100%] for PDs). Residents rated direct observation, informal advice, and self-reflection as both the top 3 most utilized and perceived most effective teaching modalities. Residents most commonly reported comfort with skills related to pain and symptom management (n = 67, 94.3%; score > 3 on 5-point Likert scale), and least commonly reported comfort with donation after cardiac death skills (n = 26-38; 44.8%-65.5%). Base specialty and time in CCM training were independently associated with comfort ratings for some, but not all, EOL skills. With respect to family meetings, residents infrequently received feedback; however, most PDs believed feedback on 6 to 10 meetings is required for competence. When PD perceptions of teaching effectiveness were compared with resident comfort ratings, differences were most apparent for skills related to pain and symptom management, cultural awareness, and ethical principles. By the end of their first subspecialty training year, PDs expect residents to be competent at most, but not all, EOL skills. In summary, trainees and programs rely on clinical activities to develop competency in EOL care, resulting in some educational gaps. Transitioning to competency-based medical education presents an opportunity to address some of these gaps, while other gaps will require more specific curricular intervention.

Correction to: Project management lessons learned from the multicentre CYCLE pilot randomized controlled trial.

Following publication of the original article [1], we have been notified that one of the authors' names is spelled incorrectly. In this Correction the incorrect and correct author name are shown.

Tranexamic acid in cardiac surgery: a systematic review and meta-analysis (protocol).

INTRODUCTION: Bleeding during cardiac surgery is associated with increased morbidity and mortality. Tranexamic acid is an antifibrinolytic with proven efficacy in major surgeries. Current clinical practice guidelines recommend intraoperative use in cardiac procedures. However, several complications have been reported with tranexamic acid including seizures. This review intends to summarise the evidence examining the efficacy and safety of tranexamic acid in patients undergoing cardiac surgery. METHODS/DESIGN: We will search MEDLINE, Embase, PubMED, ACPJC, CINAHL and the Cochrane trial registry for eligible randomised controlled trials, the search dates for all databases will be from inception until 1 January 2019, investigating the perioperative use of topical and/or intravenous tranexamic acid as a stand-alone antifibrinolytic agent compared with placebo in patients undergoing open cardiac surgery. We categorised outcomes as patient critical or patient important. Selected patient-critical outcomes are: mortality (intensive care unit, hospital and 30-day endpoints), reoperation within 24 hours, postoperative bleeding requiring transfusion of packed red blood cells, myocardial infarction, stroke, pulmonary embolism, bowel infarction, upper or lower limb deep vein thrombosis and seizures. Those outcomes, we perceived as clinical experts to be most patient valued and patients were not involved in outcomes selection process. We will not apply publication date, language, journal or methodological quality restrictions. Two reviewers will independently screen and identify eligible studies using predefined eligibility criteria and then review full reports of all potentially relevant citations. A third reviewer will resolve disagreements if consensus cannot be achieved. We will present the results as relative risk with 95% CIs for dichotomous outcomes and as mean difference or standardised mean difference for continuous outcomes with 95% CIs. We will assess the quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation approach. ETHICS AND DISSEMINATION: Formal ethical approval is not required as primary data will not be collected. The results will be disseminated through a peer-reviewed publication TRIAL REGISTRATION NUMBER: CRD42018105904.

Comparison of ventilatory modes to facilitate liberation from mechanical ventilation: protocol for a systematic review and network meta-analysis.

INTRODUCTION: Timely liberation from invasive mechanical ventilation is important to reduce the risk of ventilator-associated complications. Once a patient is deemed ready to tolerate a mode of partial ventilator assist, clinicians can use one of multiple ventilatory modes. Despite multiple trials, controversy regarding the optimal ventilator mode to facilitate liberation remains. Herein, we report the protocol for a systematic review and network meta-analysis comparing modes of ventilation to facilitate the liberation of a patient from invasive mechanical ventilation. METHODS AND ANALYSIS: We will search MEDLINE, EMBASE, PubMed, the Cochrane Library from inception to April 2019 for randomised trials that report on critically ill adults who have undergone invasive mechanical ventilation for at least 24 hours and have received any mode of assisted invasive mechanical ventilation compared with an alternative mode of assisted ventilation. Outcomes of interest will include: mortality, weaning success, weaning duration, duration of mechanical ventilation, duration of stay in the acute care setting and adverse events. Two reviewers will independently screen in two stages, first titles and abstracts, and then full texts, to identify eligible studies. Independently and in duplicate, two investigators will extract all data, and assess risk of bias in all eligible studies using the Modified Cochrane Risk of Bias tool. Reviewers will resolve disagreement by discussion and consultation with a third reviewer as necessary. Using a frequentist framework, we will perform random-effect network meta-analysis, including all ventilator modes in the same model. We will calculate direct and indirect estimates of treatment effect using a node-splitting procedure and report effect estimates using OR and 95% CI. We will assess certainty in effect estimates using Grading of Recommendations Assessment, Development and Evaluation methodology. ETHICS AND DISSEMINATION: Research ethics board approval is not necessary. The results will be disseminated through publication in a peer-reviewed journals. PROSPERO REGISTRATION NUMBER: CRD42019137786.

Project management lessons learned from the multicentre CYCLE pilot randomized controlled trial.

BACKGROUND: Clinical trials management can be studied using project management theory. The CYCLE pilot randomized controlled trial (RCT) was conducted to determine the feasibility of a future rehabilitation trial of early in-bed cycling in the intensive care unit (ICU). In-bed cycling is a novel intervention, not typically available in ICUs. Implementation of this intervention requires personnel with specialized clinical expertise caring for critically ill patients and use of the in-bed cycle. Our objective was to describe the implementation and conduct of our pilot RCT using a project management approach. METHODS: We retrospectively reviewed activities, timelines, and personnel involved in the trial. We organized activities into four project management phases: initiation, planning, execution, and monitoring and controlling. Data sources included Methods Centre documents used for trial coordination and conduct, and the trial data set. We report descriptive statistics as counts and proportions and also medians and quartiles, and we summarize the lessons learned. RESULTS: Seven ICUs in Canada participated in the trial. Time from research ethics board and contracts submission to first enrolment was a median (first quartile, third quartile) of 185 (146, 209) and 162 (114, 181) days, respectively. We trained 128 personnel on the CYCLE pilot RCT protocol, and 80 (63%) completed trial-related activities. Four sites required additional training after start-up due to staff turnover and leaves of absence. Over 15 months, we screened 864 patients: 256 were eligible and 66 were enrolled. Despite an 85% consent rate, 74% (190/256) of eligible patients were not randomized, largely (80% [152/190]) due to physiotherapist availability. Thirteen percent of recruitment weeks were lost due to physiotherapist staffing shortages. We highlight five key lessons learned: (1) prepare and anticipate site needs; (2) communicate regularly; (3) proactively analyse and act on process measure data; (4) develop contingency plans; (5) express appreciation to participating sites. CONCLUSIONS: Our analysis highlights the scope of relevant activities, rigorous training and monitoring, number and types of required personnel, and time required to conduct a multicentre ICU rehabilitation intervention trial. Our lessons learned can help others interested in implementing complex intervention trials, such as rehabilitation. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02377830 . Registered prospectively on 4 March 2015.

Cuff Leak Test and Airway Obstruction in Mechanically Ventilated ICU Patients (COMIC): a pilot randomised controlled trial protocol.

INTRODUCTION: Endotracheal intubation and invasive mechanical ventilation are lifesaving interventions that are commonly performed in the intensive care unit (ICU). Laryngeal oedema is a known complication of intubation that may cause airway obstruction in a patient on extubation. To date, the only test available to predict this complication is the cuff leak test (CLT); however, its diagnostic accuracy and utility remains uncertain. Herein, we report the protocol for the CuffLeak and AirwayObstruction in MechanicallyVentilated ICU Patients (COMIC) pilottrial. METHODS AND ANALYSIS: This will be a multicentred, pragmatic, pilot randomised controlled trial (RCT). We will enrol 100 mechanically ventilated patients in the ICU who are deemed ready for extubation. We will exclude patients at a high risk of laryngeal oedema. All enrolled patients will have a CLT done before extubation. In the intervention arm, the results of the CLT will be communicated to the bedside physician, and decision to extubate will be left to the treating team. In the control arm, respiratory therapist will not communicate the results of the CLT to the treating physician, and the patient will be extubated regardless of the CLT result. Randomisation will be done in a 1:1 allocation ratio, stratified by size of the endotracheal tube and duration of invasive mechanical ventilation.Although we will examine all clinical outcomes relevant for the future COMIC RCT, the primary outcomes of the COMIC pilottrial will be feasibility outcomes including: consent rate, recruitment rate and protocol adherence. Clinical outcomes include postextubation stridor, reintubation, emergency surgical airway, ICU mortality, in hospital mortality, duration of mechanical ventilation and ICU length of stay in days. ETHICS AND DISSEMINATION: The Hamilton Integrated Research Ethics Board, Imam Abdulrahman Bin Faisal University Institutional Review Board and Bioethical Commission of the Jagiellonian University approved this study. The trial results will be disseminated via publication in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03372707.

Diarrhoea: interventions, consequences and epidemiology in the intensive care unit (DICE-ICU): a protocol for a prospective multicentre cohort study.

INTRODUCTION: Diarrhoea is a frequent concern in the intensive care unit (ICU) and is associated with prolonged mechanical ventilation, increased length of ICU stay, skin breakdown and renal dysfunction. However, its prevalence, aetiology and prognosis in the critically ill have been poorly studied. The primary objectives of this study are to determine the incidence, risk factors and consequences of diarrhoea in critically ill adults. The secondary objectives are to estimate the incidence of Clostridium difficile-associated diarrhoea (CDAD) in ICU patients and to validate the Bristol Stool Chart and Bliss Stool Classification System characterising bowel movements in the ICU. Our primary outcome is the incidence of diarrhoea . Our secondary outcomes include: CDAD, ICU and hospital mortality and ICU and hospital length of stay. METHODS AND ANALYSIS: This international prospective cohort study will enrol patients over 10 weeks in 12 ICUs in Canada, the USA, Poland and Saudi Arabia. We will include all patients 18 years of age and older who are admitted to the ICU for at least 24 hours and follow them daily until ICU discharge. Our primary outcome is the incidence of diarrhoea based on the WHO definition, during the ICU stay. Our secondary outcomes include: CDAD, ICU and hospital mortality and ICU and hospital length of stay. We will use logistic regression to identify factors associated with diarrhoea (as defined using WHO criteria) and the kappa statistic to measure agreement on diarrhoea rates between the WHO definition and the Bristol Stool Chart and Bliss Stool Classification System. ETHICS AND DISSEMINATION: The protocol has been approved by the research ethics board of all participating centres. The diarrhoea interventions, consequences and epidemiology in the intensive care unit (DICE-ICU) study will generate evidence about diarrhoea and its frequency, predisposing factors and consequences, to inform critical care practice and future research. LAY SUMMARY: Diarrhoea is a frequent clinical problem for hospitalised patients including those who are critically ill in the ICU. Diarrhoea can cause complications such as skin damage, dehydration and kidney problems. It is not clear how common diarrhoea is in the ICU, the factors that cause it or the best way for clinicians to assess it. The DICE-ICU study is an international prospective observational study to examine the frequency, risk factors and outcomes of diarrhoea during critical illness.

The PROTROPIC feasibility study: prognostic value of elevated troponins in critical illness.

PURPOSE: Elevated cardiac troponin concentrations in people with critical illness are associated with an increased risk of death. We aimed to assess the feasibility of a larger study to ascertain the utility of cardiac troponin as a prognostic tool for mortality in critically ill patients. METHODS: Patients admitted to participating intensive care units during the one-month enrolment period were eligible. We excluded cardiac surgical patients and patients who were admitted and either died or were discharged within 12 hr. In enrolled patients, we measured high-sensitivity cardiac troponin I (hs-cTnI) and obtained electrocardiograms to ascertain the incidence of myocardial infarction (MI) and isolated troponin elevation. Our feasibility objectives were to measure recruitment rate, the proportion of patients who consented under a deferred consent model, and time required for data collection and study procedures. RESULTS: Over a four-week enrolment period, 280 patients were enrolled using a deferred consent model. We obtained subsequent consent from 81% of patients. Study procedures and data collection required 1.7 hr per participant. Overall, 86 (38%) suffered a MI, 23 (10%) had an isolated hs-cTnI elevation, and 117 (52%) had no hs-cTnI elevation. The crude hospital mortality rate was 10% without an hs-cTnI elevation, 29% with an isolated hs-cTnl elevation (relative risk [RR]) 2.2; 95% confidence interval [CI], 1.0 to 6.0) and 29% with an MI (RR, 2.6; 95% CI, 1.4 to 5.1). CONCLUSION: Myocardial injury with elevated hs-cTnI concentrations and MIs occur frequently during critical illness. This pilot study has established the feasibility of conducting a large-scale investigation addressing this issue.

Microbial dysbiosis and mortality during mechanical ventilation: a prospective observational study.

BACKGROUND: Host-associated microbial communities have important roles in tissue homeostasis and overall health. Severe perturbations can occur within these microbial communities during critical illness due to underlying diseases and clinical interventions, potentially influencing patient outcomes. We sought to profile the microbial composition of critically ill mechanically ventilated patients, and to determine whether microbial diversity is associated with illness severity and mortality. METHODS: We conducted a prospective, observational study of mechanically ventilated critically ill patients with a high incidence of pneumonia in 2 intensive care units (ICUs) in Hamilton, Canada, nested within a randomized trial for the prevention of healthcare-associated infections. The microbial profiles of specimens from 3 anatomical sites (respiratory, and upper and lower gastrointestinal tracts) were characterized using 16S ribosomal RNA gene sequencing. RESULTS: We collected 65 specimens from 34 ICU patients enrolled in the trial (29 endotracheal aspirates, 26 gastric aspirates and 10 stool specimens). Specimens were collected at a median time of 3 days (lower respiratory tract and gastric aspirates; interquartile range [IQR] 2-4) and 6 days (stool; IQR 4.25-6.75) following ICU admission. We observed a loss of biogeographical distinction between the lower respiratory tract and gastrointestinal tract microbiota during critical illness. Moreover, microbial diversity in the respiratory tract was inversely correlated with APACHE II score (r = - 0.46, p = 0.013) and was associated with hospital mortality (Median Shannon index: Discharged alive; 1.964 vs. Deceased; 1.348, p = 0.045). CONCLUSIONS: The composition of the host-associated microbial communities is severely perturbed during critical illness. Reduced microbial diversity reflects high illness severity and is associated with mortality. Microbial diversity may be a biomarker of prognostic value in mechanically ventilated patients. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT01782755 . Registered February 4 2013.

The Deferred Consent Model in a Prospective Observational Study Evaluating Myocardial Injury in the Intensive Care Unit.

BACKGROUND: Informed consent is a hallmark of ethical clinical research. An inherent challenge in critical care research is obtaining consent when patients lack decision-making capacity. One solution is deferred consent, which is often used for studies that are low risk or involve emergency interventions. Our objective was to describe a deferred consent model in a low-risk critical care study. METHODS: Prognostic Value of Elevated Troponins in Critical Illness Study was a prospective, pilot observational study of critically ill patients in 3 intensive care units, involving serial electrocardiograms and cardiac biomarkers. Newly admitted patients were enrolled over 1 month. When possible, informed consent was obtained a priori from the patient or substitute decision maker (SDM); otherwise, consent was deferred until the patient regained consent capacity or until their SDM was available. Logistic regression analysis was used to determine the association between patient's sex, Acute Physiology and Chronic Health Evaluation II score, study center, person providing consent (patient vs SDM), method of consent (telephone vs in person), and the provision or not of informed consent. RESULTS: The overall consent rate was 80.1% (213 of 266 persons approached). Of the 53 persons declining consent, 37 (69.8%) agreed to the use of data collected up until that point. Over half of all consent encounters were with patients rather than SDMs. Median interval delay between enrollment and the consent encounter was 1 day. On multivariate analysis, the only variable associated with consent was male sex of the patient (odds ratio for males 2.59, confidence interval: 1.19-5.63). CONCLUSION: Deferred consent facilitates implementation of time-sensitive research protocols until a consent encounter is possible. As a feasible alternative to exclusive a priori consent, the deferred consent model can be useful in low-risk studies in critically ill patients.

Management of Acute Respiratory Distress Syndrome and Refractory Hypoxemia. A Multicenter Observational Study.

RATIONALE: Clinicians' current practice patterns in the management of acute respiratory distress syndrome (ARDS) and refractory hypoxemia are not well described. OBJECTIVES: To describe mechanical ventilation strategies and treatment adjuncts for adults with ARDS, including refractory hypoxemia. METHODS: This was a prospective cohort study (March 2014-February 2015) of mechanically ventilated adults with moderate-to-severe ARDS requiring an FiO2 of 0.50 or greater in 24 intensive care units. RESULTS: We enrolled 664 patients: 222 (33%) with moderate and 442 (67%) with severe ARDS. On Study Day 1, mean Vt was 7.5 (SD = 2.1) ml/kg predicted body weight (n = 625); 80% (n = 501) received Vt greater than 6 ml/kg. Mean positive end-expiratory pressure (PEEP) was 10.5 (3.7) cm H2O (n = 653); 568 patients (87%) received PEEP less than 15 cm H2O. Treatment adjuncts were common (n = 440, 66%): neuromuscular blockers (n = 276, 42%), pulmonary vasodilators (n = 118, 18%), prone positioning (n = 67, 10%), extracorporeal life support (n = 29, 4%), and high-frequency oscillatory ventilation (n = 29, 4%). Refractory hypoxemia, defined as PaO2 less than 60 mm Hg on FiO2 of 1.0, occurred in 138 (21%) patients. At onset of refractory hypoxemia, mean Vt was 7.1 (SD = 2.0) ml/kg (n = 124); 95 patients (77%) received Vt greater than 6 ml/kg. Mean PEEP was 12.1 (SD = 4.4) cm H2O (n = 133); 99 patients (74%) received PEEP less than 15 cm H2O. Among patients with refractory hypoxemia, 91% received treatment adjuncts (126/138), with increased use of neuromuscular blockers (n = 87, 63%), pulmonary vasodilators (n = 57, 41%), and prone positioning (n = 32, 23%). CONCLUSIONS: Patients with moderate-to-severe ARDS receive treatment adjuncts frequently, especially with refractory hypoxemia. Paradoxically, therapies with less evidence supporting their use (e.g., pulmonary vasodilators) were over-used, whereas those with more evidence (e.g., prone positioning, neuromuscular blockade) were under-used. Patients received higher Vts and lower PEEP than would be suggested by the evidence.

Withholding Pantoprazole for Stress Ulcer Prophylaxis in Critically Ill Patients: A Pilot Randomized Clinical Trial and Meta-Analysis.

INTRODUCTION: A decreased frequency of upper gastrointestinal bleeding and a possible association of proton pump inhibitor use with Clostridium difficile and ventilator-associated pneumonia have raised concerns recently. The Reevaluating the Inhibition of Stress Erosions Pilot Trial determined the feasibility of undertaking a larger trial investigating the efficacy and safety of withholding proton pump inhibitors in critically ill patients. METHODS: In 10 ICUs, we randomized adult ICU patients anticipated to be mechanically ventilated for greater than or equal to 48 hours to receive 40 mg of IV pantoprazole daily or placebo. We excluded patients who had acute or recent gastrointestinal bleed, used dual antiplatelet agents, had a medical condition requiring proton pump inhibitor treatment, or had already received more than one dose of acid suppression daily. Patients, families, clinicians, and research staff were blinded. We conducted a systematic review and meta-analysis of similar trials. MAIN RESULTS: Ninety-one patients (49 pantoprazole and 42 placebo) from 10 centers in Canada, Saudi Arabia, and Australia were enrolled. All feasibility goals were met: 1) recruitment rate was 2.6 patients per month; 2) consent rate was 77.8%; and 3) protocol adherence was 97.7%. Upper gastrointestinal bleeding developed in 6.1% of patients in the pantoprazole group and 4.8% in the placebo group (p = 1.0). Ventilator-associated pneumonia developed in 20.4% of patients in the pantoprazole group and 14.3% in the placebo group (p = 0.58). C. difficile was identified in 4.1% pantoprazole patients and in 2.4% placebo patients (p = 1.0). We meta-analyzed five trials (604 patients) of proton pump inhibitors versus placebo; there was no statistically significant difference in the risk of upper gastrointestinal bleeding, infections, or mortality. CONCLUSIONS: Our results support the feasibility of a larger trial to evaluate the safety of withholding stress ulcer prophylaxis. Although the results are imprecise, there was no alarming increase in the risk of upper gastrointestinal bleeding; the effect of proton pump inhibitors on ventilator-associated pneumonia and C. difficile remain unclear.

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.