Stress Ulcer Prophylaxis during Invasive Mechanical Ventilation.

BACKGROUND: Whether proton-pump inhibitors are beneficial or harmful for stress ulcer prophylaxis in critically ill patients undergoing invasive ventilation is unclear. METHODS: In this international, randomized trial, we assigned critically ill adults who were undergoing invasive ventilation to receive intravenous pantoprazole (at a dose of 40 mg daily) or matching placebo. The primary efficacy outcome was clinically important upper gastrointestinal bleeding in the intensive care unit (ICU) at 90 days, and the primary safety outcome was death from any cause at 90 days. Multiplicity-adjusted secondary outcomes included ventilator-associated pneumonia, Clostridioides difficile infection, and patient-important bleeding. RESULTS: A total of 4821 patients underwent randomization in 68 ICUs. Clinically important upper gastrointestinal bleeding occurred in 25 of 2385 patients (1.0%) receiving pantoprazole and in 84 of 2377 patients (3.5%) receiving placebo (hazard ratio, 0.30; 95% confidence interval [CI], 0.19 to 0.47; P<0.001). At 90 days, death was reported in 696 of 2390 patients (29.1%) in the pantoprazole group and in 734 of 2379 patients (30.9%) in the placebo group (hazard ratio, 0.94; 95% CI, 0.85 to 1.04; P = 0.25). Patient-important bleeding was reduced with pantoprazole; all other secondary outcomes were similar in the two groups. CONCLUSIONS: Among patients undergoing invasive ventilation, pantoprazole resulted in a significantly lower risk of clinically important upper gastrointestinal bleeding than placebo, with no significant effect on mortality. (Funded by the Canadian Institutes of Health Research and others; REVISE ClinicalTrials.gov number, NCT03374800.).

Modelling the potential increase in eligible participants in clinical trials with inclusion of community intensive care unit patients in Alberta, Canada: a decision tree analysis.

PURPOSE: Critical care research in Canada is conducted primarily in academically affiliated intensive care units (ICUs) with established research infrastructure. Efforts are made to engage community hospital ICUs in research, although the impacts of their inclusion in clinical research have never been explicitly quantified. We therefore sought to determine the number of additional eligible patients that could be recruited into critical care trials and the change in time to study completion if community ICUs were included in clinical research. METHODS: We conducted a decision tree analysis using 2018 Alberta Health Services data. Patient demographics and clinical characteristics for all ICU patients were compared against eligibility criteria from ten landmark, randomized, multicentre critical care trials. Individual patients from academic and community ICUs were assessed for eligibility in each of the ten studies, and decision tree analysis models were built based on prior inclusion and exclusion criteria from those trials. RESULTS: The number of potentially eligible patients for the ten trials ranged from 2,082 to 10,157. Potentially eligible participants from community ICUs accounted for 40.0% of total potentially eligible participants. The recruitment of community ICU patients in trials would have increased potential enrolment by an average of 64.0%. The inclusion of community ICU patients was predicted to decrease time to trial completion by a mean of 14 months (43% reduction). CONCLUSION: Inclusion of community ICU patients in critical care research trials has the potential to substantially increase enrolment and decrease time to trial completion.

RéSUMé: OBJECTIF: La recherche en soins intensifs au Canada est principalement réalisée dans des unités de soins intensifs affiliées à des centres universitaires jouissant d'infrastructures de recherche bien établies. Des efforts ont été déployés pour engager les unités de soins intensifs des hôpitaux communautaires en recherche, mais les impacts de leur participation à la recherche clinique n'ont jamais été explicitement quantifiés. Nous avons conséquemment cherché à déterminer le nombre de patient·es additionnel·les pouvant être recruté·es dans des études de soins critiques ainsi que la variation du temps nécessaire pour compléter les études si la patientèle issue d'unités de soins intensifs d'hôpitaux communautaires participait à la recherche clinique. MéTHODE: Une analyse par arbre de décision a été réalisée à partir de données provenant des Alberta Health Services pour l'année 2018. Les données démographiques et les caractéristiques cliniques de tou·tes les patient·es admis·es aux soins intensifs ont été comparées avec les critères d'éligibilité de dix importantes études multicentriques, randomisées, contrôlées en soins intensifs. Les patient·es des unités de soins intensifs universitaires et communautaires ont tou·tes été évalué·es pour leur éligibilité à chacune des dix études, et des modèles d'arbres décisionnels ont été construits en se basant sur les critères originaux d'inclusion et d'exclusion. RéSULTATS: Le nombre de personnes potentiellement éligibles pour les dix études s'est situé entre 2082 et 10 157. Les patient·es potentiellement admissibles en provenance d'unités de soins intensifs communautaires ont représenté 40,0 % de toutes les personnes potentiellement admissibles. Le recrutement de patient·es en provenance d'unités de soins intensifs communautaires aurait permis une hausse moyenne du recrutement potentiel de 64,0 %. L'inclusion de patient·es des unités de soins intensifs communautaires pourrait également réduire le temps nécessaire à la complétion des études de 14 mois en moyenne (réduction de 43 %). CONCLUSION: L'inclusion de patient·es en provenance d'unités de soins intensifs d'hôpitaux communautaires dans la recherche clinique en soins critiques a le potentiel d'augmenter substantiellement le recrutement et de diminuer le temps nécessaire à la complétion des études.

Canadian intensive care unit nurses' responses to moral distress during the COVID-19 pandemic, and their recommendations for mitigative interventions.

AIMS: To describe intensive care unit nurses' experiences of moral distress during the COVID-19 pandemic, and their recommendations for mitigative interventions. DESIGN: Interpretive description. METHODS: Data were collected with a purposeful sample of 40 Canadian intensive care unit nurses between May and September 2021. Nurses completed a demographic questionnaire, the Measure of Moral Distress-Healthcare Professionals survey and in-depth interviews. Quantitative data were analysed using descriptive statistics. Qualitative data were categorized and synthesized using reflexive thematic analysis and rapid qualitative analysis. RESULTS: Half of the nurses in this sample reported moderate levels of moral distress. In response to moral distress, nurses experienced immediate and long-term effects across multiple health domains. To cope, nurses discussed varied reactions, including action, avoidance and acquiescence. Nurses provided recommendations for interventions across multiple organizations to mitigate moral distress and negative health outcomes. CONCLUSION: Nurses reported that moral distress drove negative health outcomes and attrition in response to moral events in practice. To change these conditions of moral distress, nurses require organizational investments in interventions and cultures that prioritize the inclusion of nursing perspectives and voices. IMPLICATIONS FOR THE PROFESSION: Nurses engage in a variety of responses to cope with moral distress. They possess valuable insights into the practice issues central to moral distress that have significant implications for all members of the healthcare teams, patients and systems. It is essential that nurses' voices be included in the development of future interventions central to the responses to moral distress. REPORTING METHOD: This study adheres to COREQ guidelines. IMPACT: What Problem did the Study Address? Given the known structural, systemic and environmental factors that contribute to intensive care unit nurses' experiences of moral distress, and ultimately burnout and attrition, it was important to learn about their experiences of moral distress and their recommendations for organizational mitigative interventions. Documentation of these experiences and recommendations took on a greater urgency during the context of a global health emergency, the COVID-19 pandemic, where such contextual influences on moral distress were less understood. What Were the Main Findings? Over half of the nurses reported a moderate level of moral distress. Nurses who were considering leaving nursing practice reported higher moral distress scores than those who were not considering leaving. In response to moral distress, nurses experienced a variety of outcomes across several health domains. To cope with moral distress, nurses engaged in patterns of action, avoidance and acquiescence. To change the conditions of moral distress, nurses desire organizational interventions, practices and culture changes situated in the amplification of their voices. Where and on Whom Will the Research Have an Impact on? These findings will be of interest to: (1) researchers developing and evaluating interventions that address the complex phenomenon of moral distress, (2) leaders and administrators in hospitals, and relevant healthcare and nursing organizations, and (3) nurses interested in leveraging evidence-informed recommendations to advocate for interventions to address moral distress. What Does this Paper Contribute to the Wider Global Community? This paper advances the body of scientific work on nurses' experiences of moral distress, capturing this phenomenon within the unique context of a global health emergency. Nurses' levels of moral distress using Measure of Moral Distress-Healthcare Professional survey were reported, serving as a comparator for future studies seeking to measure and evaluate intensive care unit nurses' levels of moral distress. Nurses' recommendations for mitigative interventions for moral distress have been reported, which can help inform future interventional studies. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution.

Small-Volume Blood Collection Tubes to Reduce Transfusions in Intensive Care: The STRATUS Randomized Clinical Trial.

Importance: Blood collection for laboratory testing in intensive care unit (ICU) patients is a modifiable contributor to anemia and red blood cell (RBC) transfusion. Most blood withdrawn is not required for analysis and is discarded. Objective: To determine whether transitioning from standard-volume to small-volume vacuum tubes for blood collection in ICUs reduces RBC transfusion without compromising laboratory testing procedures. Design, Setting, and Participants: Stepped-wedge cluster randomized trial in 25 adult medical-surgical ICUs in Canada (February 5, 2019 to January 21, 2021). Interventions: ICUs were randomized to transition from standard-volume (n = 10 940) to small-volume tubes (n = 10 261) for laboratory testing. Main Outcomes and Measures: The primary outcome was RBC transfusion (units per patient per ICU stay). Secondary outcomes were patients receiving at least 1 RBC transfusion, hemoglobin decrease during ICU stay (adjusted for RBC transfusion), specimens with insufficient volume for testing, length of stay in the ICU and hospital, and mortality in the ICU and hospital. The primary analysis included patients admitted for 48 hours or more, excluding those admitted during a 5.5-month COVID-19-related trial hiatus. Results: In the primary analysis of 21 201 patients (mean age, 63.5 years; 39.9% female), which excluded 6210 patients admitted during the early COVID-19 pandemic, there was no significant difference in RBC units per patient per ICU stay (relative risk [RR], 0.91 [95% CI, 0.79 to 1.05]; P = .19; absolute reduction of 7.24 RBC units/100 patients per ICU stay [95% CI, -3.28 to 19.44]). In a prespecified secondary analysis (n = 27 411 patients), RBC units per patient per ICU stay decreased after transition from standard-volume to small-volume tubes (RR, 0.88 [95% CI, 0.77 to 1.00]; P = .04; absolute reduction of 9.84 RBC units/100 patients per ICU stay [95% CI, 0.24 to 20.76]). Median decrease in transfusion-adjusted hemoglobin was not statistically different in the primary population (mean difference, 0.10 g/dL [95% CI, -0.04 to 0.23]) and lower in the secondary population (mean difference, 0.17 g/dL [95% CI, 0.05 to 0.29]). Specimens with insufficient quantity for analysis were rare (≤0.03%) before and after transition. Conclusions and Relevance: Use of small-volume blood collection tubes in the ICU may decrease RBC transfusions without affecting laboratory analysis. Trial Registration: ClinicalTrials.gov Identifier: NCT03578419.

Wellness and Coping of Physicians Who Worked in ICUs During the Pandemic: A Multicenter Cross-Sectional North American Survey.

OBJECTIVES: Few surveys have focused on physician moral distress, burnout, and professional fulfilment. We assessed physician wellness and coping during the COVID-19 pandemic. DESIGN: Cross-sectional survey using four validated instruments. SETTING: Sixty-two sites in Canada and the United States. SUBJECTS: Attending physicians (adult, pediatric; intensivist, nonintensivist) who worked in North American ICUs. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: We analysed 431 questionnaires (43.3% response rate) from 25 states and eight provinces. Respondents were predominantly male (229 [55.6%]) and in practice for 11.8 ± 9.8 years. Compared with prepandemic, respondents reported significant intrapandemic increases in days worked/mo, ICU bed occupancy, and self-reported moral distress (240 [56.9%]) and burnout (259 [63.8%]). Of the 10 top-ranked items that incited moral distress, most pertained to regulatory/organizational ( n = 6) or local/institutional ( n = 2) issues or both ( n = 2). Average moral distress (95.6 ± 66.9), professional fulfilment (6.5 ± 2.1), and burnout scores (3.6 ± 2.0) were moderate with 227 physicians (54.6%) meeting burnout criteria. A significant dose-response existed between COVID-19 patient volume and moral distress scores. Physicians who worked more days/mo and more scheduled in-house nightshifts, especially combined with more unscheduled in-house nightshifts, experienced significantly more moral distress. One in five physicians used at least one maladaptive coping strategy. We identified four coping profiles (active/social, avoidant, mixed/ambivalent, infrequent) that were associated with significant differences across all wellness measures. CONCLUSIONS: Despite moderate intrapandemic moral distress and burnout, physicians experienced moderate professional fulfilment. However, one in five physicians used at least one maladaptive coping strategy. We highlight potentially modifiable factors at individual, institutional, and regulatory levels to enhance physician wellness.

Incidence and clinical characteristics of pediatric-onset type 2 diabetes in Hong Kong: The Hong Kong childhood diabetes registry 2008 to 2017.

OBJECTIVE: With increasing prevalence of childhood obesity worldwide, the incidence of pediatric-onset type 2 diabetes (T2D) is also increasing in many countries. We aim to analyze the time trend and incidence of T2D in children in Hong Kong from 2008 to 2017, and to characterize clinical characteristics at diagnosis. METHODS: Data were retrieved from the Hong Kong Childhood Diabetes Registry. All children with T2D diagnosed at the age of less than 18 years from January 1, 2008 to December 31, 2017 and managed in the public health care system were included in this study. RESULTS: In the incident years of 2008-2017 period, 391 children were diagnosed with T2D. The crude incidence rate was 3.42 per 100,000 persons/year [95% confidence interval (CI) 3.08-3.76], which was much higher than that in last registry of 1.27 per 100,000 persons/year in 1997-2007 (P < 0.001).Most children (76%) were asymptomatic and were diagnosed by routine screening. At presentation, a significant proportion presented with co-morbidities including fatty liver (37.9%), dyslipidaemia (35.3%), hypertension (22.5%), and microalbuminuria (12.8%). CONCLUSIONS: The incidence of T2D in children has increased significantly in Hong Kong. Most of them were asymptomatic and picked up on routine health screening. Yet, comorbidities were commonly identified at diagnosis.

Needs Assessment Survey Identifying Research Processes Which may be Improved by Automation or Artificial Intelligence: ICU Community Modeling and Artificial Intelligence to Improve Efficiency (ICU-Comma).

BACKGROUND: Critical care research in Canada is conducted primarily in academically-affiliated intensive care units with established research infrastructure, including research coordinators (RCs). Recently, efforts have been made to engage community hospital ICUs in research albeit with barriers. Automation or artificial intelligence (AI) could aid the performance of routine research tasks. It is unclear which research study processes might be improved through AI automation. METHODS: We conducted a cross-sectional survey of Canadian ICU research personnel. The survey contained items characterizing opinions regarding research processes that may be amenable to AI automation. We distributed the questionnaire via email distribution lists of 3 Canadian research societies. Open-ended questions were analyzed using a thematic content analysis approach. RESULTS: A total of 49 survey responses were received (response rate: 8%). Tasks that respondents felt were time-consuming/tedious/tiresome included: screening for potentially eligible patients (74%), inputting data into case report forms (65%), and preparing internal tracking logs (53%). Tasks that respondents felt could be performed by AI automation included: screening for eligible patients (59%), inputting data into case report forms (55%), preparing internal tracking logs (51%), and randomizing patients into studies (45%). Open-ended questions identified enthusiasm for AI automation to improve information accuracy and efficiency while freeing up RCs to perform tasks that require human interaction. This enthusiasm was tempered by the need for proper AI education and oversight. CONCLUSIONS: There were balanced supportive (increased efficiency and re-allocation of tasks) and challenges (informational accuracy and oversight) with regards to AI automation in ICU research.

Effect of Awake Prone Positioning on Endotracheal Intubation in Patients With COVID-19 and Acute Respiratory Failure: A Randomized Clinical Trial.

Importance: The efficacy and safety of prone positioning is unclear in nonintubated patients with acute hypoxemia and COVID-19. Objective: To evaluate the efficacy and adverse events of prone positioning in nonintubated adult patients with acute hypoxemia and COVID-19. Design, Setting, and Participants: Pragmatic, unblinded randomized clinical trial conducted at 21 hospitals in Canada, Kuwait, Saudi Arabia, and the US. Eligible adult patients with COVID-19 were not intubated and required oxygen (≥40%) or noninvasive ventilation. A total of 400 patients were enrolled between May 19, 2020, and May 18, 2021, and final follow-up was completed in July 2021. Intervention: Patients were randomized to awake prone positioning (n = 205) or usual care without prone positioning (control; n = 195). Main Outcomes and Measures: The primary outcome was endotracheal intubation within 30 days of randomization. The secondary outcomes included mortality at 60 days, days free from invasive mechanical ventilation or noninvasive ventilation at 30 days, days free from the intensive care unit or hospital at 60 days, adverse events, and serious adverse events. Results: Among the 400 patients who were randomized (mean age, 57.6 years [SD, 12.83 years]; 117 [29.3%] were women), all (100%) completed the trial. In the first 4 days after randomization, the median duration of prone positioning was 4.8 h/d (IQR, 1.8 to 8.0 h/d) in the awake prone positioning group vs 0 h/d (IQR, 0 to 0 h/d) in the control group. By day 30, 70 of 205 patients (34.1%) in the prone positioning group were intubated vs 79 of 195 patients (40.5%) in the control group (hazard ratio, 0.81 [95% CI, 0.59 to 1.12], P = .20; absolute difference, -6.37% [95% CI, -15.83% to 3.10%]). Prone positioning did not significantly reduce mortality at 60 days (hazard ratio, 0.93 [95% CI, 0.62 to 1.40], P = .54; absolute difference, -1.15% [95% CI, -9.40% to 7.10%]) and had no significant effect on days free from invasive mechanical ventilation or noninvasive ventilation at 30 days or on days free from the intensive care unit or hospital at 60 days. There were no serious adverse events in either group. In the awake prone positioning group, 21 patients (10%) experienced adverse events and the most frequently reported were musculoskeletal pain or discomfort from prone positioning (13 of 205 patients [6.34%]) and desaturation (2 of 205 patients [0.98%]). There were no reported adverse events in the control group. Conclusions and Relevance: In patients with acute hypoxemic respiratory failure from COVID-19, prone positioning, compared with usual care without prone positioning, did not significantly reduce endotracheal intubation at 30 days. However, the effect size for the primary study outcome was imprecise and does not exclude a clinically important benefit. Trial Registration: ClinicalTrials.gov Identifier: NCT04350723.

Epigenetics of Sepsis.

OBJECTIVES: Recent evidence from the fields of microbiology and immunology, as well as a small number of human sepsis studies, suggest that epigenetic regulation may play a central role in the pathogenesis of sepsis. The term "epigenetics" refers to regulatory mechanisms that control gene expression but are not related to changes in DNA sequence. These include DNA methylation, histone modifications, and regulation of transcription via non-coding RNAs. Epigenetic modifications, occurring in response to external stressors, lead to changes in gene expression, and thus lie at the intersection between genetics and the environment. In this review, we examine data from in vitro studies, animal studies, and the existing human sepsis studies in epigenetics to demonstrate that epigenetic mechanisms are likely central to the pathogenesis of sepsis and that epigenetic therapies may have potential in the treatment of sepsis and its associated organ failures. DATA SOURCES: Online search of published scientific literature via Pubmed using the term "epigenetics" in combination with the terms "sepsis", "infection", "bacterial infection", "viral infection", "critical illness", "acute respiratory distress syndrome", and "acute lung injury". STUDY SELECTION: Articles were chosen for inclusion based on their relevance to sepsis, acute inflammation, sepsis-related immune suppression, and sepsis-related organ failure. Reference lists were reviewed to identify additional relevant articles. DATA EXTRACTION: Relevant data was extracted and synthesized for narrative review. DATA SYNTHESIS: Epigenetic regulation is a key determinant of gene expression in sepsis. At the onset of infection, host-pathogen interactions often result in epigenetic alterations to host cells that favor pathogen survival. In parallel, the host inflammatory response is characterized by epigenetic modifications in key regulatory genes, including tumor necrosis factor and interleukin-1ß. In human sepsis patients, multiple epigenetic modifying enzymes show differential expression in early sepsis, suggesting a role for epigenetics in coordinating the response to infection. In the later stages of sepsis, epigenetic modifications accompany endotoxin tolerance and the immune-suppressed state. In animal models, treatment with epigenetic modifiers can mitigate the effects of sepsis and improve survival as well as reverse sepsis-associated organ injury. CONCLUSIONS: Epigenetic modifications are associated with key phases of sepsis, from the host-pathogen interaction, to acute inflammation, to immune suppression. Epigenetic markers show promise in the diagnosis and prognosis of sepsis and epigenetic modifying agents show promise as therapeutic tools in animal models of sepsis. Human studies in the area of epigenetics are sorely lacking and should be a priority for sepsis researchers.

Epigenetic Profiling in Severe Sepsis: A Pilot Study of DNA Methylation Profiles in Critical Illness.

OBJECTIVES: Epigenetic alterations are an important regulator of gene expression in health and disease; however, epigenetic data in sepsis are lacking. To demonstrate proof of concept and estimate effect size, we performed the first epigenome-wide methylation analysis of whole blood DNA samples from a cohort of septic and nonseptic critically ill patients. DESIGN: A nested case-control study using genomic DNA isolated from whole blood from septic (n = 66) and nonseptic (n = 68) critically ill patients on "Day 1" of ICU admission. Methylation patterns were identified using Illumina 450K arrays with percent methylation expressed as ß values. After quality control, 134 participants and 414,818 autosomal cytosine-phosphate-guanine sites were used for epigenome-wide methylation analyses. SETTING: Tertiary care hospitals. SUBJECTS: Critically ill septic and nonseptic patients. INTERVENTIONS: Observational study. MEASUREMENTS AND MAIN RESULTS: A total of 668 differentially methylated regions corresponding to 443 genes were identified. Known sepsis-associated genes included complement component 3; angiopoietin 2; myeloperoxidase; lactoperoxidase; major histocompatibility complex, class I, A; major histocompatibility complex, class II, isotype DR ß I; major histocompatibility complex, class I, C; and major histocompatibility complex, class II, isotype DQ ß I. When compared with whole blood gene expression data from seven external datasets containing septic and nonseptic patients, 81% of the differentially methylated region-associated genes were differentially expressed in one or more datasets and 31% in three or more datasets. Functional analysis showed enrichment for antigen processing and presentation, methyltransferase activity, cell adhesion, and cell junctions. Analysis by weighted gene coexpression network analysis revealed DNA comethylation modules that were associated with clinical traits including severity of illness, need for vasopressors, and length of stay. CONCLUSIONS: DNA methylation marks may provide important causal and potentially biomarker information in critically ill patients with sepsis.

Increasing incidence of type 1 diabetes among Hong Kong children and adolescents: The Hong Kong Childhood Diabetes Registry 2008 to 2017.

OBJECTIVE: The incidence of childhood-onset type 1 diabetes (T1D) has been reported to be rising but there is also evidence that it has been attenuated in recent years. We described the time trends and the incidence of T1D in children in Hong Kong from 2008 to 2017 and compared with the previous local registry in 1997 to 2007. METHODS: Data were extracted from the Hong Kong Childhood Diabetes Registry, which was established in 2016. It consists of a retrospective registry (including all childhood diabetes diagnosed in 2008 to 2015) and a prospective registry (including all T1D children diagnosed from 2016 onwards). All T1D children diagnosed at the age of less than 18 years from 1 January 2008 to 31 December 2017 and managed in the public system were included in this study. RESULTS: For the incident years in the 2008 to 2017 period, a total of 498 children with T1D was identified. The crude incidence rate was 4.3 per 100 000 person/year (95% confidence interval 3.96-4.72), which was much higher than the last registry of 2.2 per 100 000 persons/year. Using general linear model, the increment is statistically significant (P = .02). When compared to the last registry, the rate of increment had attenuated, with annual increment in crude incidence in the two periods for T1D <15 years changing from 4.3% to 3.5% (P = .02). CONCLUSIONS: The incidence of T1D children increased significantly in the past two decades in Hong Kong, but the rate of increase had attenuated in recent years.

Canadian Critical Care Society clinical practice guideline: The use of vasopressin and vasopressin analogues in critically ill adults with distributive shock.

PURPOSE: Hemodynamic management of adults with distributive shock often includes the use of catecholamine-based vasoconstricting medications. It is unclear whether adding vasopressin or vasopressin analogues to catecholamine therapy is beneficial in the management of patients with distributive shock. The purpose of this guideline was to develop an evidence-based recommendation regarding the addition of vasopressin to catecholamine vasopressors in the management of adults with distributive shock. METHODS: We summarized the evidence informing this recommendation by updating a recently published meta-analysis. Then, a multidisciplinary panel from the Canadian Critical Care Society developed the recommendation using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. RESULTS: The updated systematic review identified 25 randomized controlled trials including a total of 3,737 patients with distributive shock. Compared with catecholamine therapy alone, the addition of vasopressin or its analogues was associated with a reduced risk of mortality (relative risk [RR], 0.91; 95% confidence interval [CI], 0.85 to 0.99; low certainty), reduced risk of atrial fibrillation (RR, 0.77; 95% CI, 0.67 to 0.88; high certainty), and increased risk of digital ischemia (RR, 2.56; 95% CI, 1.24 to 5.25; moderate certainty). CONCLUSIONS: After considering certainty in the evidence, values and preferences, cost, and other factors, the expert guideline panel suggests using vasopressin or vasopressin analogues in addition to catecholamines over catecholamine vasopressors alone for the management of distributive shock (conditional recommendation, low certainty evidence).

DJ-1/PARK7 Impairs Bacterial Clearance in Sepsis.

RATIONALE: Effective and rapid bacterial clearance is a fundamental determinant of outcomes in sepsis. DJ-1 is a well-established reactive oxygen species (ROS) scavenger. OBJECTIVES: Because cellular ROS status is pivotal to inflammation and bacterial killing, we determined the role of DJ-1 in bacterial sepsis. METHODS: We used cell and murine models with gain- and loss-of-function experiments, plasma, and cells from patients with sepsis. MEASUREMENTS AND MAIN RESULTS: Stimulation of bone marrow-derived macrophages (BMMs) with endotoxin resulted in increased DJ-1 mRNA and protein expression. Cellular and mitochondrial ROS was increased in DJ-1-deficient (-/-) BMMs compared with wild-type. In a clinically relevant model of polymicrobial sepsis (cecal ligation and puncture), DJ-1-/- mice had improved survival and bacterial clearance. DJ-1-/- macrophages exhibited enhanced phagocytosis and bactericidal activity in vitro, and adoptive transfer of DJ-1-/- bone marrow-derived mononuclear cells rescued wild-type mice from cecal ligation and puncture-induced mortality. In stimulated BMMs, DJ-1 inhibited ROS production by binding to p47phox, a critical component of the NADPH oxidase complex, disrupting the complex and facilitating Nox2 (gp91phox) ubiquitination and degradation. Knocking down DJ-1 (siRNA) in THP-1 (human monocytic cell line) and polymorphonuclear cells from patients with sepsis enhanced bacterial killing and respiratory burst. DJ-1 protein levels were elevated in plasma from patients with sepsis. Higher levels of circulating DJ-1 were associated with increased organ failure and death. CONCLUSIONS: These novel findings reveal DJ-1 impairs optimal ROS production for bacterial killing with important implications for host survival in sepsis.

Helicobacter pylori strains vary cell shape and flagellum number to maintain robust motility in viscous environments.

The helical shape of the human stomach pathogen Helicobacter pylori has been suggested to provide mechanical advantage for penetrating the viscous stomach mucus layer. Using single-cell tracking and quantitative morphology analysis, we document marked variation in cell body helical parameters and flagellum number among H. pylori strains leading to distinct and broad speed distributions in broth and viscous gastric mucin media. These distributions reflect both temporal variation in swimming speed and morphologic variation within the population. Isogenic mutants with straight-rod morphology showed 7-21% reduction in speed and a lower fraction of motile bacteria. Mutational perturbation of flagellum number revealed a 19% increase in speed with 4 versus 3 median flagellum number. Resistive force theory modeling incorporating variation of both cell shape and flagellum number predicts qualitative speed differences of 10-30% among strains. However, quantitative comparisons suggest resistive force theory underestimates the influence of cell body shape on speed for helical shaped bacteria.

Endotoxemia Following Multiple Trauma: Risk Factors and Prognostic Implications.

OBJECTIVE: To evaluate the prevalence and time course of systemic endotoxemia following severe multiple trauma, to define its risk factors, and to explore the correlation between post-trauma endotoxemia and organ dysfunction. DESIGN: Prospective single-center cohort study. SETTING: Emergency department and ICU of adult tertiary care level I trauma center. PATIENTS: Forty-eight severely injured (Injury Severity Score ≥ 16) patients, admitted to ICU within 24 hours of injury. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Endotoxemia was not evident on initial presentation, but developed subsequently in 75% of patients, even in the absence of Gram-negative infection. Nonsurviving patients had higher endotoxin levels than survivors on day 1 (endotoxemia, 0.48 vs 0.28; p = 0.048). Shock at admission, or surgery within the first 48 hours after trauma, was associated with higher endotoxin levels and predicted subsequent maximal endotoxemia, after adjusting for other significant covariates. Maximal endotoxemia levels were higher in patients who developed organ dysfunction, reflected in a cumulative Multiple Organ Dysfunction Score greater than 25, and patients with an intermediate endotoxemia level (≥ 0.4) had more cardiovascular dysfunction. CONCLUSIONS: It is the first study to detect increasing levels of endotoxemia following multiple trauma. Shock and early surgery predict the development of endotoxemia; endotoxemia is particularly associated with cardiovascular dysfunction. However, Gram-negative infections are uncommon in these patients, suggesting that the gastrointestinal tract is the dominant reservoir of endotoxin. Endotoxin may be an appropriate therapeutic target in patients who have sustained severe multiple trauma.

Basal Body Structures Differentially Affect Transcription of RpoN- and FliA-Dependent Flagellar Genes in Helicobacter pylori.

UNLABELLED: Flagellar biogenesis in Helicobacter pylori is regulated by a transcriptional hierarchy governed by three sigma factors, RpoD (σ(80)), RpoN (σ(54)), and FliA (σ(28)), that temporally coordinates gene expression with the assembly of the flagellum. Previous studies showed that loss of flagellar protein export apparatus components inhibits transcription of flagellar genes. The FlgS/FlgR two-component system activates transcription of RpoN-dependent genes though an unknown mechanism. To understand better the extent to which flagellar gene regulation is coupled to flagellar assembly, we disrupted flagellar biogenesis at various points and determined how these mutations affected transcription of RpoN-dependent (flaB and flgE) and FliA-dependent (flaA) genes. The MS ring (encoded by fliF) is one of the earliest flagellar structures assembled. Deletion of fliF resulted in the elimination of RpoN-dependent transcripts and an ∼4-fold decrease in flaA transcript levels. FliH is a cytoplasmic protein that functions with the C ring protein FliN to shuttle substrates to the export apparatus. Deletions of fliH and genes encoding C ring components (fliM and fliY) decreased transcript levels of flaB and flgE but had little or no effect on transcript levels of flaA. Transcript levels of flaB and flgE were elevated in mutants where genes encoding rod proteins (fliE and flgBC) were deleted, while transcript levels of flaA was reduced ∼2-fold in both mutants. We propose that FlgS responds to an assembly checkpoint associated with the export apparatus and that FliH and one or more C ring component assist FlgS in engaging this flagellar structure. IMPORTANCE: The mechanisms used by bacteria to couple transcription of flagellar genes with assembly of the flagellum are poorly understood. The results from this study identified components of the H. pylori flagellar basal body that either positively or negatively affect expression of RpoN-dependent flagellar genes. Some of these basal body proteins may interact directly with regulatory proteins that control transcription of the H. pylori RpoN regulon, a hypothesis that can be tested by examining protein-protein interactions in vitro.

Helicobacter pylori FlhA Binds the Sensor Kinase and Flagellar Gene Regulatory Protein FlgS with High Affinity.

UNLABELLED: Flagellar biogenesis is a complex process that involves multiple checkpoints to coordinate transcription of flagellar genes with the assembly of the flagellum. In Helicobacter pylori, transcription of the genes needed in the middle stage of flagellar biogenesis is governed by RpoN and the two-component system consisting of the histidine kinase FlgS and response regulator FlgR. In response to an unknown signal, FlgS autophosphorylates and transfers the phosphate to FlgR, initiating transcription from RpoN-dependent promoters. In the present study, export apparatus protein FlhA was examined as a potential signal protein. Deletion of its N-terminal cytoplasmic sequence dramatically decreased expression of two RpoN-dependent genes, flaB and flgE. Optical biosensing demonstrated a high-affinity interaction between FlgS and a peptide consisting of residues 1 to 25 of FlhA (FlhANT). The KD (equilibrium dissociation constant) was 21 nM and was characterized by fast-on (kon = 2.9 × 10(4) M(-1)s(-1)) and slow-off (koff = 6.2 × 10(-4) s(-1)) kinetics. FlgS did not bind peptides consisting of smaller fragments of the FlhANT sequence. Analysis of binding to purified fragments of FlgS demonstrated that the C-terminal portion of the protein containing the kinase domain binds FlhANT. FlhANT binding did not stimulate FlgS autophosphorylation in vitro, suggesting that FlhA facilitates interactions between FlgS and other structures required to stimulate autophosphorylation. IMPORTANCE: The high-affinity binding of FlgS to FlhA characterized in this study points to an additional role for FlhA in flagellar assembly. Beyond its necessity for type III secretion, the N-terminal cytoplasmic sequence of FlhA is required for RpoN-dependent gene expression via interaction with the C-terminal kinase domain of FlgS.

Activated neutrophils induce epithelial cell apoptosis through oxidant-dependent tyrosine dephosphorylation of caspase-8.

Activated neutrophils can injure host cells through direct effects of oxidants on membrane phospholipids, but an ability to induce apoptotic cell death has not previously been reported. We show that neutrophils activated in vivo in patients who have sustained multiple trauma or in vitro by exposure to bacterial lipopolysaccharide promote epithelial cell apoptosis through SHP-1-mediated dephosphorylation of epithelial cell caspase-8. Epithelial cell apoptosis induced by circulating neutrophils from patients who had sustained serious injury depended on the generation of neutrophil-derived reactive oxygen intermediates and was blocked by inhibition of NADPH oxidase or restoration of intracellular glutathione. Caspase-8 was constitutively tyrosine phosphorylated in a panel of resting epithelial cells, but underwent SHP-1-dependent dephosphorylation in response to hydrogen peroxide, activated neutrophils, or inhibition of Src kinases. Cells transfected with a mutant caspase-8 in which tyrosine residues at Tyr397 or Tyr465 are replaced by nonphosphorylatable phenylalanine underwent accelerated apoptosis, whereas either mutation of these residues to phosphomimetic glutamic acid or transfection with the Src kinases Lyn or c-Src inhibited hydrogen peroxide-induced apoptosis. Exposure to either hydrogen peroxide or lipopolysaccharide-stimulated neutrophils increased phosphorylation and activity of the phosphatase SHP-1, increased activity of caspases 8 and 3, and accelerated epithelial cell apoptosis. These observations reveal a novel mechanism for neutrophil-mediated tissue injury through oxidant-dependent, SHP-1-mediated dephosphorylation of caspase-8 resulting in enhanced epithelial cell apoptosis.