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Background: Biosampling studies in critically ill patients traditionally involve bedside collection of samples followed by local processing (ie. centrifugation, aliquotting, and freezing) and storage. However, community hospitals, which care for the majority of Canadian patients, often lack the infrastructure for local processing and storage of specimens. A potential solution is a "simplified" biosampling protocol whereby blood samples are collected at the bedside and then shipped to a central site for processing and storage. One potential limitation of this approach is that delayed processing may alter sample characteristics., Objective: To determine whether delays in blood sample processing affect the stability of cytokines (IL-6, TNF, IL-10, IFN-γ), chemokines (IL-8, IP-10, MCP-1, MCP-4, MIP-1α, MIP-1β), cell-free DNA (cfDNA) (released by dying cells), and blood clotting potential in human blood samples., Methods: Venous blood was collected into EDTA and citrate sample tubes and stored at room temperature (RT) or 4°C for progressive intervals up to 72 hours, prior to processing. Plasma cytokines and chemokines were quantified using single or multiplex immunoassays. cfDNA was measured using Picogreen DNA Quantification. Blood clotting potential was measured using a thrombin generation assay., Results: Blood samples were collected from 9 intensive care unit (ICU) patients and 7 healthy volunteers. Admission diagnoses for the ICU patients included sepsis, trauma, ruptured abdominal aortic aneurysm, intracranial hemorrhage, gastrointestinal bleed, and hyperkalemia. After pre-processing delays of up to 72 hours at RT or 4°C, no significant changes were observed in plasma cytokines, chemokines, cfDNA, or thrombin formation., Conclusions: Delayed sample processing for up to 72 hours at either RT or 4°C did not significantly affect cytokines, chemokines, cfDNA, or blood clotting potential in plasma samples from healthy volunteers and ICU patients. A "simplified" biosampling protocol is a feasible solution for conducting biosampling research at hospitals without local processing capacity., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Gyorffy et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Viable pathogen-laden droplets of consistent quality are essential for reliably assessing the protection offered by facemasks against airborne infections. We identified a significant gap in guidance within standardized tests for evaluating the filtration efficiencies of facemask materials using viable bacteria-laden aerosol droplets. An aerosol platform, built according to the American Society for Testing and Materials standard F2101-19, was used to validate and standardize facemask filtration test procedures. We utilized this platform to investigate the impact of varying five operating parameters, namely suspension media composition, relative humidity, pathogen concentration, and atomizer airflow and feed flow rates, on the aerosol quality of viable bacteria-laden aerosols. We achieved consistent generation of 1,700 to 3,000 viable bacteria-laden droplets sized between 2.7 and 3.3 µm under the following optimized test conditions: 1.5% w/v peptone water concentration, ≥80% relative humidity at 24 ± 2 °C, 1 × 10 5 CFU/mL bacterial concentration, 1.5 L/min atomizer airflow rate, and 170 μL/min feed flow rate. We also explored the consequence of deviating from these optimized test parameters on viable bacteria-laden aerosol quality. These results highlight the importance of controlling these parameters when studying airborne transmission and control., (© The Author(s) 2024. Published by Oxford University Press on behalf of National Academy of Sciences.)

Background: Although intravenous tranexamic acid is used in cardiac surgery to reduce bleeding and transfusion, topical tranexamic acid results in lower plasma concentrations compared with intravenous tranexamic acid, which may lower the risk of seizures. We aimed to determine whether topical tranexamic acid reduces the risk of in-hospital seizure without increasing the risk of transfusion among cardiac surgery patients., Methods: We conducted a multicenter, double dummy, blinded, randomized controlled trial of patients recruited by convenience sampling in academic hospitals undergoing cardiac surgery with cardiopulmonary bypass. Between September 17, 2019, and November 28, 2023, a total of 3242 patients from 16 hospitals in 6 countries were randomly assigned (1:1 ratio) to receive either intravenous tranexamic acid (control) through surgery or topical tranexamic acid (treatment) at the end of surgery. The primary outcome was seizure, and the secondary outcome was red blood cell transfusion. After the last planned interim analysis, when 75% of anticipated participants had completed follow up, the data and safety monitoring board recommended to terminate the trial, and upon unblinding, the operations committee stopped the trial for safety., Results: Among 3242 randomized patients (mean age, 66.0 years; 77.7% male), in-hospital seizure occurred in 4 of 1624 patients (0.2%) in the topical group, and 11 of 1628 patients (0.7%) in the intravenous group (absolute risk difference, -0.5% [95% CI, -0.9 to 0.03]; P =0.07). Red blood cell transfusion occurred in 570 patients (35.1%) in the topical group and in 433 (26.8%) in the intravenous group (absolute risk difference, 8.3% [95% CI, 5.2-11.5]; P =0.007). The absolute risk difference in transfusion of ≥4 units of red blood cells in the topical group compared with the intravenous group was 8.2% (95% CI, 3.4-12.9)., Conclusions: Among patients undergoing cardiac surgery, topical administration of tranexamic acid resulted in an 8.3% absolute increase in transfusion without reducing the incidence of seizure, compared with intravenous tranexamic acid., Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03954314., Competing Interests: Dr Devereaux is employed as a professor at McMaster University. Dr Spence is employed as an anesthesiologist and intensivist at Hamilton Health Sciences and reports consultant fees from AOP Pharmaceuticals and PhaseBio outside the submitted work. Dr Whitlock reports grants from Abbott Canada during the conduct of the study and consultant fees from AtriCure Inc and Cytosorbents outside the submitted work. Dr Belley-Côté reports grants from Abbott Laboratories, Bayer, Bristol-Myers Squibb, Pfizer, and Roche Diagnostics Corporation during the conduct of the study and consultant fees from Trimedic Therapeutics outside the submitted work. Dr Arora reports other funding from Bioporto, Edwards Lifesciences, HLS Therapeutics Inc, and Renibus Therapeutics Inc outside the submitted work. The other authors report no conflicts.

Purpose: We aimed to identify whether social determinants of health (SDoH) are associated with the development of sepsis and assess the differences between individuals living within systematically disadvantaged neighbourhoods compared with those living outside these neighbourhoods., Methods: We conducted a single-centre case-control study including 300 randomly selected adult patients (100 patients with sepsis and 200 patients without sepsis) admitted to the emergency department of a large academic tertiary care hospital in Hamilton, ON, Canada. We collected data on demographics and a limited set of SDoH variables, including neighbourhood household income, smoking history, social support, and history of alcohol disorder. We analyzed study data using multivariate logistic regression models., Results: The study included 100 patients with sepsis with a median [interquartile range (IQR)] age of 75 [58-84] yr and 200 patients without sepsis with a median [IQR] age of 72 [60-83] yr. Factors significantly associated with sepsis included arrival by ambulance, absence of a family physician, higher Hamilton Early Warning Score, and a recorded history of dyslipidemia. Important SDoH variables, such as individual or household income and race, were not available in the medical chart. In patients with SDoH available in their medical records, no SDoH was significantly associated with sepsis. Nevertheless, compared with their proportion of the Hamilton population, the rate of sepsis cases and sepsis deaths was approximately two times higher among patients living in systematically disadvantaged neighbourhoods., Conclusions: This study revealed the lack of available SDoH data in electronic health records. Despite no association between the SDoH variables available and sepsis, we found a higher rate of sepsis cases and sepsis deaths among individuals living in systematically disadvantaged neighbourhoods. Including SDoH in electronic health records is crucial to study their effect on the risk of sepsis and to provide equitable care., (© 2024. The Author(s).)

Sepsis is a global health threat with significant morbidity and mortality. Despite clinical practice guidelines and developed health systems, sepsis is often unrecognized or misdiagnosed, leading to preventable harm. In Canada, sepsis is responsible for 1 in 20 deaths and is a significant driver of health system costs. Despite being a signatory to the World Health Organization's Resolution WHA 70.7, adopted in 2017, Canada has not lived up to its commitment. Many existing sepsis policies were developed in response to a specific tragedy, and there is no national sepsis action plan. In this article, we describe the burden of sepsis, provide examples of existing, context-specific, reactionary sepsis policies, and urge a coordinated, proactive Canadian sepsis action plan to reduce the burden of sepsis., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: GG is an employee of the Canadian Medical Protective Association. NK is the president of the Global Sepsis Alliance. LS is funded by the Arnold L. Johnson Chair in Health Care Ethics, an endowed Chair at McMaster University. AFR is the Scientific Director of Sepsis Canada, a CIHR-funded network, and holds the Hamilton Health Sciences Chair in Sepsis Research. KB has consulted for Fresenius Medical Care. The other authors have no conflicts of interest to declare.

Background: Critical illness requiring invasive mechanical ventilation can precipitate important functional disability, contributing to multidimensional morbidity following admission to an intensive care unit (ICU). Early in-bed cycle ergometry added to usual physiotherapy may mitigate ICU-acquired physical function impairment., Methods: We randomly assigned 360 adult ICU patients undergoing invasive mechanical ventilation to receive 30 minutes of early in-bed Cycling + Usual physiotherapy (n=178) or Usual physiotherapy alone (n=182). The primary outcome was the Physical Function ICU Test-scored (PFIT-s) at 3 days after discharge from the ICU (the score ranges from 0 to 10, with higher scores indicating better function)., Results: Cycling began within a median (interquartile range) of 2 (1 to 3) days of starting mechanical ventilation; patients received 3 (2 to 5) cycling sessions for a mean (±standard deviation) of 27.2 ± 6.6 minutes. In both groups, patients started Usual physiotherapy within 2 (2 to 4) days of mechanical ventilation and received 4 (2 to 7) Usual physiotherapy sessions. The duration of Usual physiotherapy was 23.7 ± 15.1 minutes in the Cycling + Usual physiotherapy group and 29.1 ± 13.2 minutes in the Usual physiotherapy group. No serious adverse events occurred in either group. Among survivors, the PFIT-s at 3 days after discharge from the ICU was 7.7 ± 1.7 in the Cycling + Usual physiotherapy group and 7.5 ± 1.7 in the Usual physiotherapy group (absolute difference, 0.23 points; 95% confidence interval, -0.19 to 0.65; P=0.29)., Conclusions: Among adults receiving mechanical ventilation in the ICU, adding early in-bed Cycling to usual physiotherapy did not improve physical function at 3 days after discharge from the ICU compared with Usual physiotherapy alone. Cycling did not cause any serious adverse events. (Funded by the Canadian Institutes of Health Research and others; ClinicalTrials.gov numbers, NCT03471247 [full randomized clinical trial] and NCT02377830 [CYCLE Vanguard 46-patient internal pilot].).

Objectives: Although clinicians may use methylene blue (MB) in refractory septic shock, the effect of MB on patient-important outcomes remains uncertain. We conducted a systematic review and meta-analysis to investigate the benefits and harms of MB administration in patients with septic shock., Data Sources: We searched six databases (including PubMed, Embase, and Medline) from inception to January 10, 2024., Study Selection: We included randomized clinical trials (RCTs) of critically ill adults comparing MB with placebo or usual care without MB administration., Data Extraction: Two reviewers performed screening, full-text review, and data extraction. We pooled data using a random-effects model, assessed the risk of bias using the modified Cochrane tool, and used Grading of Recommendations Assessment, Development, and Evaluation to rate certainty of effect estimates., Data Synthesis: We included six RCTs (302 patients). Compared with placebo or no MB administration, MB may reduce short-term mortality (RR [risk ratio] 0.66 [95% CI, 0.47-0.94], low certainty) and hospital length of stay (mean difference [MD] -2.1 d [95% CI, -1.4 to -2.8], low certainty). MB may also reduce duration of vasopressors (MD -31.1 hr [95% CI, -16.5 to -45.6], low certainty), and increase mean arterial pressure at 6 hours (MD 10.2 mm Hg [95% CI, 6.1-14.2], low certainty) compared with no MB administration. The effect of MB on serum methemoglobin concentration was uncertain (MD 0.9% [95% CI, -0.2% to 2.0%], very low certainty). We did not find any differences in adverse events., Conclusions: Among critically ill adults with septic shock, based on low-certainty evidence, MB may reduce short-term mortality, duration of vasopressors, and hospital length of stay, with no evidence of increased adverse events. Rigorous randomized trials evaluating the efficacy of MB in septic shock are needed., Registration: Center for Open Science (https://osf.io/hpy4j)., Competing Interests: Dr. Seely holds patents related to multiorgan variability analysis and has shares in Therapeutic Monitoring Systems. Dr. Cook is supported by a Canada Research Chair in Critical Care Knowledge Translation. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2024 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine.)

Introduction: Despite older adults being more vulnerable to sepsis, most preclinical research on sepsis has been conducted using young animals. This results in decreased scientific validity since age is an independent predictor of poor outcome. In this study, we explored the impact of aging on the host response to sepsis using the fecal-induced peritonitis (FIP) model developed by the National Preclinical Sepsis Platform (NPSP)., Methods: C57BL/6 mice (3 or 12 months old) were injected intraperitoneally with rat fecal slurry (0.75 mg/g) or a control vehicle. To investigate the early stage of sepsis, mice were culled at 4 h, 8 h, or 12 h to investigate disease severity, immunothrombosis biomarkers, and organ injury. Mice received buprenorphine at 4 h post-FIP. A separate cohort of FIP mice were studied for 72 h (with buprenorphine given at 4 h, 12 h, and then every 12 h post-FIP and antibiotics/fluids starting at 12 h post-FIP). Organs were harvested, plasma levels of Interleukin (IL)-6, IL-10, monocyte chemoattract protein (MCP-1)/CCL2, thrombin-antithrombin (TAT) complexes, cell-free DNA (CFDNA), and ADAMTS13 activity were quantified, and bacterial loads were measured., Results: In the 12 h time course study, aged FIP mice demonstrated increased inflammation and injury to the lungs compared to young FIP mice. In the 72 h study, aged FIP mice exhibited a higher mortality rate (89%) compared to young FIP mice (42%) (p < 0.001). Aged FIP non-survivors also exhibited a trend towards elevated IL-6, TAT, CFDNA, CCL2, and decreased IL-10, and impaired bacterial clearance compared to young FIP non-survivors., Conclusion: To our knowledge, this is the first study to investigate the impact of age on survival using the FIP model of sepsis. Our model includes clinically-relevant supportive therapies and inclusion of both sexes. The higher mortality rate in aged mice may reflect increased inflammation and worsened organ injury in the early stage of sepsis. We also observed trends in impaired bacterial clearance, increase in IL-6, TAT, CFDNA, CCL2, and decreased IL-10 and ADAMTS13 activity in aged septic non-survivors compared to young septic non-survivors. Our aging model may help to increase the scientific validity of preclinical research and may be useful for identifying mechanisms of age-related susceptibility to sepsis as well as age-specific treatment strategies., (© 2024. The Author(s).)

Abstract: Sepsis is defined as a life-threatening organ dysfunction caused by excessive host response to infection, and represents the most common cause of in-hospital deaths. Sepsis accounts for 30% of all critically ill patients in the intensive care unit (ICU), and has a global mortality rate of 20%. Activation of blood coagulation during sepsis and septic shock can lead to disseminated intravascular coagulation, which is characterized by microvascular thrombosis. Von Willebrand factor (VWF) and ADAMTS13 are two important regulators of blood coagulation that may be important links between sepsis and mortality in the ICU. Herein we review our current understanding of VWF and ADAMTS13 in sepsis and other critical illnesses and discuss their contribution to disease pathophysiology, their use as markers of severe illness, and potential targets for new therapeutic development., (Copyright © 2023 by the Shock Society.)

Background: Preclinical sepsis models have been criticized for their inability to recapitulate human sepsis and suffer from methodological shortcomings that limit external validity and reproducibility. The National Preclinical Sepsis Platform (NPSP) is a consortium of basic science researchers, veterinarians, and stakeholders in Canada undertaking standardized multi-laboratory sepsis research to increase the efficacy and efficiency of bench-to-bedside translation. In this study, we aimed to develop and characterize a 72-h fecal-induced peritonitis (FIP) model of murine sepsis conducted in two independent laboratories. The experimental protocol was optimized by sequentially modifying dose of fecal slurry and timing of antibiotics in an iterative fashion, and then repeating the experimental series at site 1 and site 2., Results: Escalating doses of fecal slurry (0.5-2.5 mg/g) resulted in increased disease severity, as assessed by the modified Murine Sepsis Score (MSS). However, the MSS was poorly associated with progression to death during the experiments, and mice were found dead without elevated MSS scores. Administration of early antibiotics within 4 h of inoculation rescued the animals from sepsis compared with late administration of antibiotics after 12 h, as evidenced by 100% survival and reduced bacterial load in peritoneum and blood in the early antibiotic group. Site 1 and site 2 had statistically significant differences in mortality (60% vs 88%; p < 0.05) for the same dose of fecal slurry (0.75 mg/g) and marked differences in body temperature between groups., Conclusions: We demonstrate a systematic approach to optimizing a 72-h FIP model of murine sepsis for use in multi-laboratory studies. Alterations to experimental conditions, such as dose of fecal slurry and timing of antibiotics, have clear impact on outcomes. Differences in mortality between sites despite rigorous standardization warrants further investigations to better understand inter-laboratory variation and methodological design in preclinical studies., (© 2023. The Author(s).)

Evaluating risk for sepsis is complicated due to limited understanding of how social determinants of health (SDoH) influence the occurence of the disease. This scoping review aims to identify gaps and summarize the existing literature on SDoH and the development of sepsis in adults., Data Sources: A literature search using key terms related to sepsis and SDoH was conducted using Medline and PubMed., Study Selection: Studies were screened by title and abstract and then full text in duplicate. Articles were eligible for inclusion if they: 1) evaluated at least one SDoH on the development of sepsis, 2) participants were 18 years or older, and 3) the studies were written in English between January 1970 and January 2022. Systematic reviews, meta-analyses, editorials, letters, commentaries, and studies with nonhuman participants were excluded., Data Extraction: Data were extracted in duplicate using a standardized data extraction form. Studies were grouped into five categories according to the SDoH they evaluated (race, socioeconomic status [SES], old age and frailty, health behaviors, and social support). The study characteristics, key outcomes related to incidence of sepsis, mortality, and summary statements were included in tables., Data Synthesis: The search identified 637 abstracts, 20 of which were included after full-text screening. Studies evaluating SES, old age, frailty, and gender demonstrated an association between sepsis incidence and the SDoH. Studies that examined race demonstrated conflicting conclusions as to whether Black or White patients were at increased risk of sepsis. Overall, a major limitation of this analysis was the methodological heterogeneity between studies., Conclusions: There is evidence to suggest that SDoH impacts sepsis incidence, particularly SES, gender, old age, and frailty. Future prospective cohort studies that use standardized methods to collect SDoH data, particularly race-based data, are needed to inform public health efforts to reduce the incidence of sepsis and help clinicians identify the populations most at risk., Competing Interests: The authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2022 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine.)

Protein C is a vitamin K dependant protein in plasma that plays an essential role in regulating the coagulation cascade and inflammatory response. As a result of its importance in these roles, it has been suggested as a biomarker for prognosis of patients affected by sepsis. Sepsis is a dysregulated host response to an infection that is the leading cause of mortality in U.S. hospitals and results in the highest cost of hospitalization. It was found that protein C concentration in non-surviving sepsis patients is significantly lower (1.8 μg mL -1 ) than in survivors and healthy patients who have a protein C concentration of 3.9-5.9 μg mL -1 . Current methods for diagnosing sepsis rely on expensive immunoassays or functional assays that require multiple steps for isolation and activation of protein C. We demonstrate in this paper a low cost, single step assay for detection of protein C in blood plasma. This was done by combining isoelectric gates with barium-immobilized metal affinity trapping. The electric field was optimized for use with immobilized metal affinity using COMSOL simulation. The integrated device was tested with samples containing buffered protein C, protein C in the presence of high concentration bovine serum albumin and alpha 1-proteinase inhibitor, and in blood plasma with spiked protein C. The stability of the measured values was tested by monitoring the intensity of a mixture of protein C with BSA and A1PI every minute to determine that measurement after 40 minutes was optimal. The results showed that the device could be used to distinguish a reduction in protein C from 4.46 μg mL -1 to 1.96 μg mL -1 with greater than 98% confidence in plasma making it suitable for sepsis prognosis.

Cell-free DNA (cfDNA) content in plasma has been studied as a biomarker for sepsis. Recent publications show that the cfDNA content in sepsis patients entering intensive care unit who were likely to survive had a total cfDNA concentration of 1.16 ± 0.13 μg/mL compared to 4.65 ± 0.48 μg/mL of non-survivors. Current methods for measuring cfDNA content in plasma were designed to amplify and measure low concentrations of specific DNA, making them unsuitable for low-cost measurement of total cfDNA content in plasma. Here, we have developed a point of care (POC) device that uses a thread silicone device as a medium to store a fluorescent dye which eliminates the need for preparatory steps, external aliquoting and dispensing of reagents, preconcentration, and external mixing while reducing the detection cost. The device was paired with a portable imaging system with an excitation filter at 472 ± 10 nm and an emission filter of 520 ± 10 nm that can be operated with just 100 mA current supply. The device was demonstrated for use in the quantification of buffered cfDNA samples in a range 1-6 μg/mL with a sensitivity of 5.72 AU/μg/mL and with cfDNA spiked in plasma with a range of 1-3 μg/mL and a sensitivity of 5.43 AU/μg/mL. The results showed that the device could be used as a low-cost, rapid, and portable POC device for differentiating between survivors and non-survivors of sepsis within 20 min., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: Sepsis, the dysregulated host response to infection, triggers abnormal pro-coagulant and pro-inflammatory host responses. Limitations in early disease intervention highlight the need for effective diagnostic and prognostic biomarkers. Protein C's role as an anticoagulant and anti-inflammatory molecule makes it an appealing target for sepsis biomarker studies. This meta-analysis aims to assess the diagnostic and prognostic value of protein C (PC) as a biomarker for adult sepsis., Methods: We searched MEDLINE, PubMed, EMBASE, CINAHL and Cochrane Library from database inception to September 12, 2021. We included prospective observational studies of (1) adult patients (> 17) with sepsis or suspicion of sepsis that; (2) measured PC levels with 24 h of study admission with; and (3) the goal of examining PC as a diagnostic or prognostic biomarker. Two authors screened articles and conducted risk of bias (RoB) assessment, using the Quality in Prognosis Studies (QUIPS) and the Quality Assessment in Diagnostic Studies-2 (QUADAS-2) tools. If sufficient data were available, meta-analysis was conducted to estimate the standardized mean difference (SMD) between patient populations., Results: Twelve studies were included, and 8 were synthesized for meta-analysis. Pooled analysis demonstrated moderate certainty of evidence that PC levels were less reduced in sepsis survivors compared to non-survivors (6 studies, 741 patients, SMD = 0.52, 95% CI 0.24-0.81, p = 0.0003, I 2  = 55%), and low certainty of evidence that PC levels were less reduced in septic patients without disseminated intravascular coagulation (DIC) compared to those with DIC (3 studies, 644 patients, SMD = 0.97, 95% CI 0.62-1.32, p < 0.00001, I 2  = 67%). PC could not be evaluated as a diagnostic tool due to heterogeneous control populations between studies., Conclusion and Relevance: Our review demonstrates that PC levels were significantly higher in sepsis survivors compared to non-survivors and patients with sepsis but not disseminated intravascular coagulation (DIC). Our evaluation is limited by high RoB in included studies and poor reporting of the sensitivity and specificity of PC as a sepsis biomarker. Future studies are needed to determine the sensitivity and specificity of PC to identify its clinical significance as a biomarker for early sepsis recognition. Trial Registration PROSPERO registration number: CRD42021229786. The study protocol was published in BMJ Open., (© 2022. The Author(s).)

Purpose: In response to the rapid spread of SARS-CoV-2, hospitals in Canada enacted temporary visitor restrictions to limit the spread of COVID-19 and preserve personal protective equipment supplies. This study describes the extent, variation, and fluctuation of Canadian adult intensive care unit (ICU) visitation policies before and during the first wave of the COVID-19 pandemic., Methods: We conducted an environmental scan of Canadian hospital visitation policies throughout the first wave of the pandemic. We conducted a two-phased study analyzing both quantitative and qualitative data., Results: We collected 257 documents with reference to visitation policies (preCOVID, 101 [39%]; midCOVID, 71 [28%]; and lateCOVID, 85 [33%]). Of these 257 documents, 38 (15%) were ICU-specific and 70 (27%) referenced the ICU. Most policies during the midCOVID/lateCOVID pandemic period allowed no visitors with specific exceptions (e.g., end-of-life). Framework analysis revealed five overarching themes: 1) reasons for restricted visitation policies; 2) visitation policies and expectations; 3) exceptions to visitation policy; 4) patient and family-centred care; and 5) communication and transparency., Conclusions: During the first wave of the COVID-19 pandemic, most Canadian hospitals had public-facing visitor restriction policies with specific exception categories, most commonly for patients at end-of-life, patients requiring assistance, or COVID-19 positive patients (varying from not allowed to case-by-case). Further studies are needed to understand the consistency with which visitation policies were operationalized and how they may have impacted patient- and family-centred care., (© 2021. The Author(s).)

Rationale: Understanding the magnitude of moral distress and its associations may point to solutions. Objectives: To understand the magnitude of moral distress and other measures of wellness in Canadian critical care physicians, to determine any associations among these measures, and to identify potentially modifiable factors. Methods: This was an online survey of Canadian critical care physicians whose e-mail addresses were registered with either the Canadian Critical Care Society or the Canadian Critical Care Trials Group. We used validated measures of moral distress, burnout, compassion fatigue, compassion satisfaction, and resilience. We also measured selected individual, practice, and workload characteristics. Results: Of the 499 physicians surveyed, 239 (48%) responded and there were 225 usable surveys. Respondents reported moderate scores of moral distress (107 ± 59; mean ± standard deviation, maximum 432), one-third of respondents had considered leaving or had previously left a position because of moral distress, about one-third met criteria for burnout syndrome, and a similar proportion reported medium-high scores of compassion fatigue. In contrast, about one-half of respondents reported a high score of compassion satisfaction, and overall, respondents reported a moderate score of resilience. Each of the "negative" wellness measures (moral distress, burnout, and compassion fatigue) were associated directly with each of the other "negative" wellness measures, and inversely with each of the "positive" wellness measures (compassion satisfaction and resilience), but moral distress was not associated with resilience. Moral distress was lower in respondents who were married or partnered compared with those who were not, and the prevalence of burnout was lower in respondents who had been in practice for longer. There were no differences in any of the wellness measures between adult and pediatric critical care physicians. Conclusions: Canadian critical care physicians report moderate scores of moral distress, burnout, and compassionate fatigue, and moderate-high scores of compassion satisfaction and resilience. We found no modifiable factors associated with any wellness measures. Further quantitative and qualitative studies are needed to identify interventions to reduce moral distress, burnout, and compassion fatigue.

Sepsis is a life-threatening disease characterized by excessive host response to infection that can lead to activation of the coagulation system. Von Willebrand Factor (VWF) and ADAMTS13 are important regulators of hemostasis and their dysregulation during sepsis progression is not well understood. Herein we characterize ADAMTS13 and VWF in septic and non-septic patients. ADAMTS13 activity, ADAMTS13 antigen, VWF antigen, myeloperoxidase, and protein C, were measured in plasma collected from 40 septic patients (20 non-survivors and 20 survivors) and 40 non-septic patients on the first and last day of their ICU stay. ADAMTS13 activity and ADAMTS13 antigen were reduced, whereas VWF antigen was elevated among septic patients compared to non-septic patients and healthy controls. Non-septic patients also exhibited elevated VWF antigen and reduced ADAMTS13 activity, but to a lesser extent than septic patients. Non-survivor septic patients exhibited the lowest levels of ADAMTS13 activity. ADAMTS13 activity:antigen ratio was similar across all patient cohorts suggesting that the specific activity of ADAMTS13 remains unchanged. Therefore, reduced ADAMTS13 function in circulation is likely due to a reduction in circulating levels. We suggest that massive release of VWF in response to inflammation consumes limited circulating ADAMTS13, resulting in the imbalance observed between VWF and ADAMTS13 among septic and to a lesser extent in non-septic ICU patients. Changes to ADAMTS13 did not correlate with myeloperoxidase or protein C levels. Reduced ADAMTS13 activity and antigen, and elevated VWF antigen observed among all patient cohorts on admission remained unchanged in survivors at ICU discharge. Prolonged reduction in ADAMTS13 activity and antigen in septic patients coincides with elevated levels of VWF. The persistent abnormalities in ADAMTS13 and VWF in sepsis patients discharged from the ICU may contribute to a sustained prothrombotic state., Competing Interests: The authors have declared that no competing interests exists.

Objectives: In many jurisdictions, ethical concerns require surrogate humane endpoints to replace death in small animal models of acute lung injury. Heterogenous selection and reporting of surrogate endpoints render interpretation and generalizability of findings between studies difficult. We aimed to establish expert-guided consensus among preclinical scientists and laboratory animal veterinarians on selection and reporting of surrogate endpoints, monitoring of these models, and the use of analgesia., Design: A three-round consensus process, using modified Delphi methodology, with researchers who use small animal models of acute lung injury and laboratory animal veterinarians who provide care for these animals. Statements on the selection and reporting of surrogate endpoints, monitoring, and analgesia were generated through a systematic search of MEDLINE and Embase. Participants were asked to suggest any additional potential statements for evaluation., Setting: A web-based survey of participants representing the two stakeholder groups (researchers, laboratory animal veterinarians). Statements were rated on level of evidence and strength of support by participants. A final face-to-face meeting was then held to discuss results., Subjects: None., Interventions: None., Measurements and Main Results: Forty-two statements were evaluated, and 29 were rated as important, with varying strength of evidence. The majority of evidence was based on rodent models of acute lung injury. Endpoints with strong support and evidence included temperature changes and body weight loss. Behavioral signs and respiratory distress also received support but were associated with lower levels of evidence. Participants strongly agreed that analgesia affects outcomes in these models and that none may be necessary following nonsurgical induction of acute lung injury. Finally, participants strongly supported transparent reporting of surrogate endpoints. A prototype composite score was also developed based on participant feedback., Conclusions: We provide a preliminary framework that researchers and animal welfare committees may adapt for their needs. We have identified knowledge gaps that future research should address., Competing Interests: Drs. McGinn, Fergusson, Barron, Liu, and Lalu institutions received funding from Canadian Institutes of Health Research (CIHR). Dr. Kristof received funding from Ottawa Hospital Research Institute (travel costs). Dr. Downey received support for article research from the National Institutes of Health. Dr. Brown received support for article research from CIHR. Dr. dos Santos disclosed that she is funded by CIHR. Dr. Lalu is supported by The Ottawa Hospital Anesthesia Alternate Funds Association and the University of Ottawa Junior Research Chair in Innovative Translational Research. All of work was completed at the Ottawa Hospital Research Institute in Ottawa, ON, Canada. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2020 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)

Background: A limitation of diagnostic scoring systems for disseminated intravascular coagulation (DIC) is that once DIC is identified, it may be in a state of irreversible deterioration., Objectives: To identify hemostatic markers that can identify the pre-DIC state., Methods: This was a multi-center observational study of 357 septic patients. The incidence of DIC was determined using the International Society on Thrombosis and Haemostasis (ISTH) DIC Score. Markers of interest include components of the DIC score: protein C (PC), antithrombin (AT), and citrullinated histones (H3Cit), which is a marker of NETosis., Results: Out of 357 sepsis patients, 236 patients did not develop DIC (without-DIC), 79 patients had DIC on Day 1 (overt-DIC), and 42 patients developed DIC after Day 1 (pre-DIC). Compared to without-DIC patients, pre-DIC patients had decreased platelet count, increased international normalized ratio (INR), decreased PC and AT, and increased H3Cit. In contrast, D-dimer and fibrinogen levels did not differ between pre-DIC and without-DIC patients. Using receiver operating characteristics (ROC) analysis, we found that platelet count and INR in combination with PC and AT could discriminate pre-DIC from without-DIC. The area under the curve in the ROC analysis was 0.83 (95% confidence interval, 0.76 to 0.89)., Conclusion: Our study suggests that platelets and INR in combination with PC and AT can identify the pre-DIC state in septic patients. In contrast, D-dimer increased and fibrinogen decreased in the late (ie, overt) stages of DIC. Our data also suggest that NETosis contributes to the onset of DIC in sepsis., (© 2020 International Society on Thrombosis and Haemostasis.)

The accuracy of the signs and tests that clinicians use to diagnose ventilator-associated pneumonia (VAP) and initiate antibiotic treatment has not been well characterized. We sought to characterize and compare the accuracy of physical examination, chest radiography, endotracheal aspirate (ETA), bronchoscopic sampling cultures (protected specimen brush [PSB] and bronchoalveolar lavage [BAL]), and CPIS > 6 to diagnose VAP. We searched six databases from inception through September 2019 and selected English-language studies investigating accuracy of any of the above tests for VAP diagnosis. Reference standard was histopathological analysis. Two reviewers independently extracted data and assessed study quality. We included 25 studies (1639 patients). The pooled sensitivity and specificity of physical examination findings for VAP were poor: fever (66.4% [95% confidence interval [CI]: 40.7-85.0], 53.9% [95% CI 34.5-72.2]) and purulent secretions (77.0% [95% CI 64.7-85.9], 39.0% [95% CI 25.8-54.0]). Any infiltrate on chest radiography had a sensitivity of 88.9% (95% CI 73.9-95.8) and specificity of 26.1% (95% CI 15.1-41.4). ETA had a sensitivity of 75.7% (95% CI 51.5-90.1) and specificity of 67.9% (95% CI 40.5-86.8). Among bronchoscopic sampling methods, PSB had a sensitivity of 61.4% [95% CI 43.7-76.5] and specificity of 76.5% [95% CI 64.2-85.6]; while BAL had a sensitivity of 71.1% [95% CI 49.9-85.9] and specificity of 79.6% [95% CI 66.2-85.9]. CPIS > 6 had a sensitivity of 73.8% (95% CI 50.6-88.5) and specificity of 66.4% (95% CI 43.9-83.3). Classic clinical indicators had poor accuracy for diagnosis of VAP. Reliance upon these indicators in isolation may result in misdiagnosis and potentially unnecessary antimicrobial use.

Introduction: Sepsis is a major source of morbidity and mortality in neonates; however, identification of the causative pathogens is challenging. Many neonates have negative blood cultures despite clinical evidence of sepsis. Next-generation sequencing (NGS) is a high-throughput, parallel sequencing technique for DNA. Pathogen-targeted enrichment followed by NGS has the potential to be more sensitive and faster than current gold-standard blood culture. In this pilot study, we will test the feasibility and pathogen detection patterns of pathogen-targeted NGS in neonates with suspected sepsis. Additionally, the distribution and diagnostic accuracy of biomarkers cell-free DNA and protein C levels at two time points will be explored., Methods and Analysis: We will conduct a prospective, pilot observational study. Neonates over 1 kg with suspected sepsis from a single tertiary care children's hospital will be recruited for the study. Recruitment will be censored at 200 events or 6 months' duration. Two blood study samples will be taken: the first simultaneous to the blood culture (time=0 hour, for NGS and biomarkers) via an exception to consent (deferred consent) and another 24 hours later after prospective consent (biomarkers only). Neonates will be adjudicated into those with clinical sepsis, culture-proven sepsis and without sepsis based on clinical criteria. Feasibility parameters (eg, recruitment) and NGS process time will be reported.For analysis, NGS results will be described in aggregate, compared with the simultaneous blood culture (sensitivity and specificity) and reviewed via expert panel for plausibility. Pilot data for biomarker distribution and diagnostic accuracy (sensitivity and specificity) for distinguishing between septic and non-septic neonates will be reported., Ethics and Dissemination: Ethics approval has been granted by the Hamilton Integrated Research Ethics Board. We will seek publication of study results in peer-reviewed journals., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Critically ill patients in the intensive care unit (ICU) are at risk for central line-associated bloodstream infection (CLABSI) with an incidence up to 6.9 per 1000 catheter days. CLABSI has a significant attributable mortality and increases in-hospital length of stay, readmissions, and costs. Chlorhexidine gluconate (CHG), a broad-spectrum biocide, has been shown to effectively reduce infections including CLABSI; however, few trials have utilized CHG for prevention of central line infections. Our preclinical work has demonstrated a device that diffuses CHG into the intravenous lock solution of central venous catheters and decreases bacterial growth on the catheter lumen. We designed a clinical trial to test the feasibility of using a CHG device in an ICU patient population., Methods: The proposed pilot trial will be a single centre, open-label, two-arm, parallel group feasibility randomized controlled trial (RCT). Participants will have a central line in situ and will be enrolled within 72 h of admittance to 3 ICUs at a single academic hospital. Exclusion criteria will include suspected infection, chronic indwelling catheters, and CHG allergy. Informed consent will be obtained from eligible participants or their substitute decision maker prior to randomization. Participants will be randomized to receive either usual care or the CHG locking device. Blood cultures will be drawn from all participants every 48 h. The primary objective of this study will be to determine the feasibility of using this protocol to conduct a larger trial. Feasibility will be assessed through the following outcomes: (1) consent rate, (2) recruitment rate, (3) protocol adherence, and (4) comfort level with the device. The secondary objective of this study will be to establish the preliminary efficacy of the device., Discussion: This study will be the first human RCT to investigate a CHG locking device for the prevention of central line infections. Findings from this trial will inform the feasibility of conducting a large RCT and provide preliminary data on the efficacy of a CHG locking device., Trial Registration: ClinicalTrials.gov, NCT03309137, registered on October 13, 2017., Competing Interests: Competing interestsICU Medical and ATTWILL do not have input into the design or implementation of this study or have access to study data until analysis is complete. ICU Medical was involved in training the bedside nursing staff on appropriate use of ChloraLockTM. AFR did not receive any personal financial compensation for conducting the trial., (© The Author(s). 2020.)

To determine if a set of time-varying biological indicators can be used to: 1) predict the sepsis mortality risk over time and 2) generate mortality risk profiles., Design: Prospective observational study., Setting: Nine Canadian ICUs., Subjects: Three-hundred fifty-six septic patients., Interventions: None., Measurements and Main Results: Clinical data and plasma levels of biomarkers were collected longitudinally. We used a complementary log-log model to account for the daily mortality risk of each patient until death in ICU/hospital, discharge, or 28 days after admission. The model, which is a versatile version of the Cox model for gaining longitudinal insights, created a composite indicator (the daily hazard of dying) from the "day 1" and "change" variables of six time-varying biological indicators (cell-free DNA, protein C, platelet count, creatinine, Glasgow Coma Scale score, and lactate) and a set of contextual variables (age, presence of chronic lung disease or previous brain injury, and duration of stay), achieving a high predictive power (conventional area under the curve, 0.90; 95% CI, 0.86-0.94). Including change variables avoided misleading inferences about the effects of day 1 variables, signifying the importance of the longitudinal approach. We then generated mortality risk profiles that highlight the relative contributions among the time-varying biological indicators to overall mortality risk. The tool was validated in 28 nonseptic patients from the same ICUs who became septic later and was subject to 10-fold cross-validation, achieving similarly high area under the curve., Conclusions: Using a novel version of the Cox model, we created a prognostic tool for septic patients that yields not only a predicted probability of dying but also a mortality risk profile that reveals how six time-varying biological indicators differentially and longitudinally account for the patient's overall daily mortality risk., Competing Interests: Drs. Liaw, Dwivedi, and Medeiros received support for article research from the Canadian Institutes of Health Research (CIHR). Drs. Liaw and Medeiros disclosed government work. Dr. Fox-Robichaud’s institution received funding from CIHR, CIHR/Natural Sciences and Engineering Research Council of Canada, and Hamilton Academic Hospital Fund. Dr. Dodek’s institution received funding from McMaster University. Dr. Winston received grant support from the Alberta Lung Association and the Canadian Intensive Care Foundation. Dr. Lellouche received compensation for patient inclusions in the study, and he disclosed he is a co-founder, administrator, and consultant of Oxynov, R&D company. Dr. Marshall received patient recruitment fees per CIHR grant, and he received funding from Data Monitoring Committee, Asahi Kasei Pharmaceuticals and Baxter. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2019 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine.)

Background: Circulating cell-free DNA (cfDNA) may contribute to the pathophysiology of post-injury inflammation and coagulation in trauma. However, the source and mechanism of release of cfDNA in trauma is not well understood. One potential source of cfDNA is from Neutrophil Extracellular Traps (NETs), released by activated neutrophils during the process of NETosis. The primary objective of our study was to determine if cfDNA has prognostic utility in trauma. The secondary objective of this study was to determine the source of cfDNA in trauma compared to sepsis., Methods: We studied trauma patients from two prospective observational cohort studies: the DNA as a Prognostic Marker in ICU Patients (DYNAMICS) study and the Endotoxin in Polytrauma (ENPOLY) study. We also studied septic patients from the DYNAMICS study. Citrated plasma samples were collected longitudinally from the patients (days 1 to 7). The following molecules were measured in the plasma samples: cfDNA, protein C (PC), myeloperoxidase (MPO) (a marker of neutrophil activation), citrullinated Histone H3 (H3Cit, a marker of NETosis), cyclophilin A (a marker of necrosis), and caspase-cleaved K18 (a marker of apoptosis)., Results: A total of 77 trauma patients were included (n = 38 from DYNAMICS and n = 39 from ENPOLY). The median age was 49 years; 27.3% were female, and mortality was 16.9% at 28 days. Levels of cfDNA were elevated compared to healthy values but not significantly different between survivors and non-survivors. There was a positive correlation between MPO and cfDNA in septic patients (r = 0.424, p < 0.001). In contrast, there was no correlation between MPO and cfDNA in trauma patients (r = - 0.192, p = 0.115). Levels of H3Cit, a marker of NETosis, were significantly elevated in septic patients compared to trauma patients (p < 0.01) while apoptosis and necrosis markers did not differ between the two groups., Conclusion: Our studies suggest that the source and mechanism of release of cfDNA differ between trauma and sepsis patients. In sepsis, cfDNA is likely primarily released by activated neutrophils via the process of NETosis. In contrast, cfDNA in trauma appears to originate mainly from injured or necrotic cells. Although cfDNA is elevated in trauma and sepsis patients compared to healthy controls, cfDNA does not appear to have prognostic utility in trauma patients., Trial Registration: ClinicalTrials.gov Identifier: NCT01355042 . Registered May 17, 2011.

Background: Rapid response teams (RRTs) respond to hospitalized patients experiencing clinical deterioration and help determine subsequent management and disposition. We sought to evaluate and compare the prognostic accuracy of the Hamilton Early Warning Score (HEWS) and the National Early Warning Score 2 (NEWS2) for prediction of in-hospital mortality following RRT activation. We secondarily evaluated a subgroup of patients with suspected infection., Methods: We retrospectively analyzed prospectively collected data (2012-2016) of consecutive RRT patients from two hospitals. The primary outcome was in-hospital mortality. We calculated the number needed to examine (NNE), which indicates the number of patients that need to be evaluated in order to detect one future death., Results: Five thousand four hundred ninety-one patients were included, of whom 1837 (33.5%) died in-hospital. Mean age was 67.4 years, and 51.6% were male. A HEWS above the low-risk threshold (≥ 5) had a sensitivity of 75.9% (95% confidence interval (CI) 73.9-77.9) and specificity of 67.6% (95% CI 66.1-69.1) for mortality, with a NNE of 1.84. A NEWS2 above the low-risk threshold (≥ 5) had a sensitivity of 84.5% (95% CI 82.8-86.2), and specificity of 49.0% (95% CI: 47.4-50.7), with a NNE of 2.20. The area under the receiver operating characteristic curve (AUROC) was 0.76 (95% CI 0.75-0.77) for HEWS and 0.72 (95% CI: 0.71-0.74) for NEWS2. Among suspected infection patients (n = 1708), AUROC for HEWS was 0.79 (95% CI 0.76-0.81) and for NEWS2, 0.75 (95% CI 0.73-0.78)., Conclusions: The HEWS has comparable clinical accuracy to NEWS2 for prediction of in-hospital mortality among RRT patients.

Introduction: Acute rehabilitation in critically ill patients can improve post-intensive care unit (post-ICU) physical function. In-bed cycling early in a patient's ICU stay is a promising intervention. The objective of this study was to determine the feasibility of recruitment, intervention delivery and retention in a multi centre randomised clinical trial (RCT) of early in-bed cycling with mechanically ventilated (MV) patients., Methods: We conducted a pilot RCT conducted in seven Canadian medical-surgical ICUs. We enrolled adults who could ambulate independently before ICU admission, within the first 4 days of invasive MV and first 7 days of ICU admission. Following informed consent, patients underwent concealed randomisation to either 30 min/day of in-bed cycling and routine physiotherapy (Cycling) or routine physiotherapy alone (Routine) for 5 days/week, until ICU discharge. Our feasibility outcome targets included: accrual of 1-2 patients/month/site; >80% cycling protocol delivery; >80% outcomes measured and >80% blinded outcome measures at hospital discharge. We report ascertainment rates for our primary outcome for the main trial (Physical Function ICU Test-scored (PFIT-s) at hospital discharge)., Results: Between 3/2015 and 6/2016, we randomised 66 patients (36 Cycling, 30 Routine). Our consent rate was 84.6 % (66/78). Patient accrual was (mean (SD)) 1.1 (0.3) patients/month/site. Cycling occurred in 79.3% (146/184) of eligible sessions, with a median (IQR) session duration of 30.5 (30.0, 30.7) min. We recorded 43 (97.7%) PFIT-s scores at hospital discharge and 37 (86.0%) of these assessments were blinded., Discussion: Our pilot RCT suggests that a future multicentre RCT of early in-bed cycling for MV patients in the ICU is feasible., Trial Registration Number: NCT02377830., Competing Interests: Competing interests: Restorative Therapies (Baltimore, MD) provided 2 RT-300 supine cycle ergometers for Toronto General Hospital and London Health Sciences sites for this research.

Atherosclerosis is a complex disease that involves alterations in lipoprotein metabolism and inflammation. Protein and lipid glycosylation events, such as sialylation, contribute to the development of atherosclerosis and are regulated by specific glycosidases, including sialidases. To evaluate the effect of the sialidase neuraminidase 1 (NEU1) on atherogenesis, here we generated apolipoprotein E (ApoE)-deficient mice that express hypomorphic levels of NEU1 ( Neu1 hypo Apoe -/- ). We found that the hypomorphic NEU1 expression in male Apoe -/- mice reduces serum levels of very-low-density lipoprotein (VLDL) and LDL cholesterol, diminishes infiltration of inflammatory cells into lesions, and decreases aortic sinus atherosclerosis. Transplantation of Apoe -/- bone marrow (BM) into Neu1 hypo Apoe -/- mice significantly increased atherosclerotic lesion development and had no effect on serum lipoprotein levels. Moreover, Neu1 hypo Apoe -/- mice exhibited a reduction in circulating monocyte and neutrophil levels and had reduced hyaluronic acid and P-selectin adhesion capability on monocytes/neutrophils and T cells. Consistent with these findings, administration of a sialidase inhibitor, 2-deoxy-2,3-dehydro- N -acetylneuraminic acid, had a significant anti-atherogenic effect in the Apoe -/- mice. In summary, the reduction in NEU1 expression or function decreases atherosclerosis in mice via its significant effects on lipid metabolism and inflammatory processes. We conclude that NEU1 may represent a promising target for managing atherosclerosis., (© 2018 White et al.)

Background: Despite increasing ethical standards for conducting animal research, death is still often used as an endpoint in mouse sepsis studies. Recently, the Murine Sepsis Score (MSS), Mouse Clinical Assessment Score for Sepsis (M-CASS), and Mouse Grimace Scale (MGS) were developed as surrogate endpoint scoring systems for assessing pain and disease severity in mice. The objective of our study was to compare the effectiveness of these scoring systems and monitoring of body temperature for predicting disease progression and death in the cecal ligation and puncture (CLP) sepsis model, in order to better inform selection of surrogate endpoints for death in experimental sepsis., Methods: C57Bl/6J mice were subjected to control sham surgery, or moderate or severe CLP sepsis. All mice were monitored every 4 h for surrogate markers of death using modified versions of the MSS, M-CASS, and MGS scoring systems until 24 h post-operatively, or until endpoint (inability to ambulate) and consequent euthanasia., Results: Thirty percent of mice subjected to moderate severity CLP reached endpoint by 24 h post-CLP, whereas 100% undergoing severe CLP reached endpoint within 20 h. Modified MSS, M-CASS, and MGS scores all increased, while body temperature decreased, in a time-dependent and sepsis severity-dependent manner, although modified M-CASS scores showed substantial variability. Receiver operating characteristic curves demonstrate that the last recorded body temperature (AUC = 0.88; 95% CI 0.77-0.99), change in body temperature (AUC = 0.89; 95% CI 0.78-0.99), modified M-CASS (AUC = 0.93; 95% CI 0.85-1.00), and modified MSS (AUC = 0.95; 95% CI 0.88-1.01) scores are all robust for predicting death in CLP sepsis, whereas modified MGS (AUC = 0.78; 95% CI 0.63-0.92) is less robust., Conclusions: The modified MSS and body temperature are effective markers for assessing disease severity and predicting death in the CLP model, and should thus be considered as valid surrogate markers to replace death as an endpoint in mouse CLP sepsis studies.

Lipoteichoic acid (LTA) and lipopolysaccharide (LPS) are bacterial lipids that stimulate pro-inflammatory cytokine production, thereby exacerbating sepsis pathophysiology. Proprotein convertase subtilisin/kexin type 9 (PCSK9) negatively regulates uptake of cholesterol by downregulating hepatic lipoprotein receptors, including low-density lipoprotein (LDL) receptor (LDLR) and possibly LDLR-related protein-1 (LRP1). PCSK9 also negatively regulates Gram-negative LPS uptake by hepatocytes, however this mechanism is not completely characterized and mechanisms of Gram-positive LTA uptake are unknown. Therefore, our objective was to elucidate the mechanisms through which PCSK9 regulates uptake of LTA and LPS by investigating the roles of lipoproteins and lipoprotein receptors. Here we show that plasma PCSK9 concentrations increase transiently over time in septic and non-septic critically ill patients, with highly similar profiles over 14 days. Using flow cytometry, we demonstrate that PCSK9 negatively regulates LDLR-mediated uptake of LTA and LPS by HepG2 hepatocytes through an LDL-dependent mechanism, whereas LRP1 and high-density lipoprotein do not contribute to this uptake pathway. Bacterial lipid uptake by hepatocytes was not associated with cytokine production or hepatocellular injury. In conclusion, our study characterizes an LDL-dependent and LDLR-mediated bacterial lipid uptake pathway regulated by PCSK9, and provides evidence in support of PCSK9 inhibition as a potential therapeutic strategy for sepsis.

Background: Rapid response teams have been widely adopted across the world. Although evidence for their efficacy is not clear, they remain a popular means to detect and react to patient deterioration. This may in part be due to there being no standardized approach to their usage or implementation. A key component of their ability to be effective is the speed of response., Objective: The objective of this review is to evaluate the effect of delayed response by rapid response teams on hospital mortality (primary), cardiac arrest, and intensive care transfer rates (secondary)., Methods: This review will include randomized and non-randomized studies which examined the effect of delayed response times by rapid response teams on patient mortality, cardiac arrest, and intensive care unit admission rates. This review will include studies of adult patients who have experienced a rapid response team consultation. The search strategy will utilize a combination of keywords and MeSH terms. MEDLINE and Embase will be searched, as well as examining gray literature. Two reviewers will independently screen retrieved citations to determine if they meet inclusion criteria. Studies will be selected that provide information about the impact of response time on patient outcomes. Comparisons will be made between consults that arrive in a timely manner and consults that are delayed. Quality assessment of randomized studies will be conducted in accordance with guidelines from the Cochrane Handbook for Systematic Reviews of Interventions. Quality assessment of non-randomized studies will be based on the Risk of Bias in Non-randomized Studies-of Interventions (ROBINS-I) assessment tool. Results of the review will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines., Discussion: This systematic review will identify and synthesize evidence around the impact of delayed response by rapid response teams on patient mortality, cardiac arrest, and intensive care transfer rates., Systematic Review Registration: PROSPERO Registration: CRD42017071842 .

Vascular catheters are a major cause of nosocomial bloodstream infections. ChloraLock (ATTWILL Medical Solutions, Inc, West Jordan, UT, and ICU Medical, Inc, San Clemente, CA) is a novel antimicrobial device containing chlorhexidine digluconate (CHG) that is fitted onto a syringe and infuses CHG into the catheter lumen during locking. The objective of this study was to evaluate the antimicrobial efficacy of ChloraLock with in vitro tests and its ability to reduce Staphylococcus aureus contamination of catheters in the external jugular veins of Yorkshire swine. ChloraLock significantly reduced the bacterial load in the in vitro tests by up to 6 log10 colony-forming units (CFU) and by 3 to 4 log10 CFU/lumen in vivo in a swine model with 0.9% NaCl catheter locks.

Purpose: To identify elements which enable patient and family centred care (PFCC) in the intensive care unit (ICU) and priorities for PFCC research., Materials and Methods: We engaged a panel of multidisciplinary stakeholders in a modified Delphi process. Items generated from a literature review and panelist suggestions were rated in 3 successive rounds on a scale from 1 to 7. Median score was used to rate each item's priority, with 5 or more indicating "essential priority," 4 or 5 "moderate priority" and 3 or less "low priority." Interquartile range (IQR) was used to measure consensus, with IQR of 1 indicating "high" consensus, 2 "moderate" consensus, and 3 or greater "low" consensus., Results: Six items were rated essential elements for facilitating PFCC with high consensus (flexible visiting hours, family participation in bedside care, trained family support person, interventions to facilitate continuity of care, staff education to support families, continuity of staff assignments). Three items were rated essential research topics: interventions to facilitate continuity of care following ICU discharge (moderate consensus), family participation in bedside care (low consensus), and decision aids for end of life decision-making (low consensus)., Conclusions: Stakeholders identified clear and distinct priorities for PFCC in clinical care and research, though there was greater consensus for clinical care., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Fluid resuscitation is a crucial therapy for sepsis, and the use of balanced fluids and/or isotonic albumin may improve patient survival. We have previously demonstrated that resuscitation with normal saline results in increased hepatic leukocyte recruitment in a murine model of sepsis. Given that clinical formulations of albumin are in saline, our objectives were to develop a novel balanced electrolyte solution specifically for sepsis and to determine if supplementing this solution with albumin would improve the inflammatory response in sepsis., Methods: We developed two novel buffered electrolyte solutions that contain different concentrations of acetate and gluconate, named Seplyte L and Seplyte H, and administered these solutions with or without 5% albumin. Normal saline with or without albumin and Ringer's lactate served as controls. Sepsis was induced by cecal ligation and puncture (CLP), and the liver microvasculature was imaged in vivo at 6 h after CLP to quantify leukocyte recruitment. Hepatic cytokine expression and plasma cell-free DNA (cfDNA) concentrations were also measured., Results: Septic mice receiving either Seplyte fluid showed significant reductions in hepatic post-sinusoidal leukocyte rolling and adhesion compared to normal saline. Hepatic cytokine concentrations varied in response to different concentrations of acetate and gluconate in the novel resuscitation fluids but were unaffected by albumin. All Seplyte fluids significantly increased hepatic TNF-α levels at 6 h compared to control fluids. However, Seplyte H exhibited a similar cytokine profile to the control fluids for all other cytokines, whereas mice given Seplyte L had significantly elevated IL-6, IL-10, KC (CXCL1), and MCP-1 (CCL2). Plasma cfDNA was generally increased during sepsis, but resuscitation fluid composition did not significantly affect cfDNA concentrations., Conclusions: Electrolyte concentrations and buffer constituents of resuscitation fluids can modulate hepatic cytokine production and leukocyte recruitment in septic mice, while the effects of albumin are modest during early sepsis. Therefore, crystalloid fluid choice should be an important consideration for resuscitation in sepsis, and the effects of fluid composition on inflammation in other organ systems should be studied to better understand the physiological impact of this vital sepsis therapy.

Clinical practice guidelines are systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances. These documents inform and shape patient care around the world. In this Perspective we discuss the importance of diversity on guideline panels, the disproportionately low representation of women on critical care guideline panels, and existing initiatives to increase the representation of women in corporations, universities, and government. We propose five strategies to ensure gender parity within critical care medicine.

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 p47 phox , a critical component of the NADPH oxidase complex, disrupting the complex and facilitating Nox2 (gp91 phox ) 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.

Objectives: Sepsis is characterized by systemic activation of inflammatory and coagulation pathways in response to infection. Recently, it was demonstrated that histones released into the circulation by dying/activated cells may contribute to sepsis pathology. Although the ability of extracellular histones to modulate the procoagulant activities of several cell types has been investigated, the influence of histones on the hemostatic functions of circulating monocytes is unknown. To address this, we investigated the ability of histones to modulate the procoagulant potential of THP-1 cells and peripheral blood monocytes, and examined the effects of plasmas obtained from septic patients to induce a procoagulant phenotype on monocytic cells., Methods/results: Tissue factor (TF) activity assays were performed on histone-treated THP-1 cells and blood monocytes. Exposure of monocytic cells to histones resulted in increases in TF activity, TF antigen, and phosphatidylserine exposure. Histones modulate the procoagulant activity via engagement of Toll-like receptors 2 and 4, and this effect was abrogated with inhibitory antibodies. Increased TF activity of histone-treated cells corresponded to enhanced thrombin generation in plasma determined by calibrated automated thrombography. Finally, TF activity was increased on monocytes exposed to plasma from septic patients, an effect that was attenuated in plasma from patients receiving unfractionated heparin (UFH)., Conclusions: Our studies suggest that increased levels of extracellular histones found in sepsis contribute to dysregulated coagulation by increasing TF activity of monocytes. These procoagulant effects can be partially ameliorated in sepsis patients receiving UFH, thereby identifying extracellular histones as a potential therapeutic target for sepsis treatment.

Introduction: Proprotein convertase subtilisin/kexin type 9 (PCSK9) targets lipoprotein receptors for degradation, thereby reducing hepatic lipid clearance. PCSK9 inhibition reduces mortality in septic mice, presumably through increased hepatic clearance of pathogen lipids due to increased lipoprotein receptor concentrations. However, PCSK9 overexpression in vivo has not been studied in sepsis. Therefore, this study aimed to evaluate the effects of differential PCSK9 expression on systemic infection, inflammation, and coagulation in sepsis., Methods: Wild-type, PCSK9 knockout (KO), and transgenic (Tg) mice that overexpress PCSK9 were subjected to sham surgery or cecal ligation and puncture (CLP). Bacterial loads were measured in lungs, peritoneal cavity fluid, and blood. Organ pathology was assessed in lungs, liver, and kidneys. Lung myeloperoxidase activity, and plasma concentrations of alanine aminotransferase (ALT), creatinine, cell-free DNA (cfDNA), protein C, thrombin-antithrombin (TAT) complexes, interleukin (IL)-6, and IL-10 were also measured 6 h postoperatively. Morbidity was assessed for 16 h following CLP., Results: Overexpression of PCSK9 in mice increased liver and kidney pathology, plasma IL-6, ALT, and TAT concentrations during sepsis, whereas PCSK9 KO mice exhibited reduced bacterial loads, lung and liver pathology, myeloperoxidase activity, plasma IL-10, and cfDNA during CLP-induced sepsis. All septic mice had reduced plasma levels of protein C, but the protein C ratio relative to normal was significantly decreased in PCSK9 Tg mice. Dyspnea, cyanosis, and overall grimace scores were greatest in septic mice overexpressing PCSK9, whereas PCSK9 KO mice retained core body temperature during sepsis., Conclusion: These findings demonstrate that PCSK9 deficiency confers protection against systemic bacterial dissemination, organ pathology, and tissue inflammation, particularly in the lungs and liver, while PCSK9 overexpression exacerbates multi-organ pathology as well as the hypercoagulable and pro-inflammatory states in early sepsis.

The opportunistic pathogen Pseudomonas aeruginosa causes a wide range of infections in multiple hosts by releasing an arsenal of virulence factors such as pyocyanin. Despite numerous reports on the pleiotropic cellular targets of pyocyanin toxicity in vivo, its impact on erythrocytes remains elusive. Erythrocytes undergo an apoptosis-like cell death called eryptosis which is characterized by cell shrinkage and phosphatidylserine (PS) externalization; this process confers a procoagulant phenotype on erythrocytes as well as fosters their phagocytosis and subsequent clearance from the circulation. Herein, we demonstrate that P. aeruginosa pyocyanin-elicited PS exposure and cell shrinkage in erythrocyte while preserving the membrane integrity. Mechanistically, exposure of erythrocytes to pyocyanin showed increased cytosolic Ca(2+) activity as well as Ca(2+) -dependent proteolytic processing of μ-calpain. Pyocyanin further up-regulated erythrocyte ceramide abundance and triggered the production of reactive oxygen species. Pyocyanin-induced increased PS externalization in erythrocytes translated into enhanced prothrombin activation and fibrin generation in plasma. As judged by carboxyfluorescein succinimidyl-ester labelling, pyocyanin-treated erythrocytes were cleared faster from the murine circulation as compared to untreated erythrocytes. Furthermore, erythrocytes incubated in plasma from patients with P. aeruginosa sepsis showed increased PS exposure as compared to erythrocytes incubated in plasma from healthy donors. In conclusion, the present study discloses the eryptosis-inducing effect of the virulence factor pyocyanin, thereby shedding light on a potentially important mechanism in the systemic complications of P. aeruginosa infection., (© 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Background: Technique failure in peritoneal dialysis (PD) due to fibrosis and angiogenesis is complicated by peritonitis. Staphylococcus aureus infection is one of the most common causes of peritonitis in PD. The heparan sulfate proteoglycan, syndecan-1 (CD138), was reported to regulate fibrosis, angiogenesis, inflammation and S. aureus infection. The objectives of this study were to examine the effects of syndecan-1 on S. aureus infection and histopathology in a PD model., Results: Syndecan-1(-/-) and wild type mice were dialyzed for 4 weeks and infected intraperitoneally with S. aureus. Tissues were collected after 4 h for histomorphometric analysis. Intravital microscopy was used to observe leukocyte recruitment and to quantify syndecan-1 in the parietal peritoneum microcirculation. The dialyzed syndecan-1(-/-) mice were more susceptible to S. aureus infection than undialyzed syndecan-1(-/-) controls and wild type animals. However, peritoneal fibrosis and neovascularization due to PD did not differ between syndecan-1(-/-) and wild type mice. Intravital microscopy showed that in S. aureus infection, syndecan-1 was removed from the subendothelial layer of peritoneal venules but syndecan-1 deficiency did not affect leukocyte recruitment., Conclusions: This study indicates that, while syndecan-1 is important for providing a barrier to acute S. aureus infection in PD, it does not affect peritoneal fibrosis and angiogenesis.

Unlabelled: ♦, Background: The objective of this study was to examine the effects of a conventional dialysis solution and peritoneal catheter on leukocyte-endothelial cell interactions in the microcirculation of the parietal peritoneum in a subacute peritoneal dialysis (PD) mouse model. ♦, Methods: An intraperitoneal (IP) catheter with a subcutaneous injection port was implanted into mice and, after a 2-week healing period, the animals were injected daily for 6 weeks with a 2.5% dextrose solution. Intravital microscopy (IVM) of the parietal peritoneum microcirculation was performed 4 hours after the last injection of the dialysis solution. Leukocyte-endothelial cell interactions were quantified and compared with catheterized controls without dialysis treatment and naïve mice. ♦, Results: The number of rolling and extravascular leukocytes along with peritoneal fibrosis and neovascularization were significantly increased in the catheterized animals compared with naïve mice but did not significantly differ between the 2 groups of catheterized animals with sham injections or dialysis solution treatment. ♦, Conclusion: The peritoneal catheter implant increased leukocyte rolling and extravasation, peritoneal fibrosis and vascularization in the parietal peritoneum independently from the dialysis solution treatment., (Copyright © 2016 International Society for Peritoneal Dialysis.)

Objectives: Sepsis is characterized by systemic activation of inflammation and coagulation in response to infection. In sepsis, activated neutrophils extrude neutrophil extracellular traps composed of cell-free DNA (CFDNA) that not only trap pathogens but also provide a stimulus for clot formation. Although the effect of CFDNA on coagulation has been extensively studied, much less is known about the impact of CFDNA on fibrinolysis. To address this, we (1) investigated the relationship between CFDNA levels and fibrinolytic activity in sepsis and (2) determined the mechanisms by which CFDNA modulates fibrinolysis., Approach and Results: Plasma was collected from healthy and septic individuals, and CFDNA was quantified. Clot lysis assays were performed in plasma and purified systems, and lysis times were determined by monitoring absorbance. Clot morphology was assessed using scanning electron microscopy. Clots formed in plasma from septic patients containing >5 µg/mL CFDNA were dense in structure and resistant to fibrinolysis, a phenomenon overcome by deoxyribonuclease addition. These effects were recapitulated in control plasma supplemented with CFDNA. In a purified system, CFDNA delayed fibrinolysis but did not alter tissue-type plasminogen activator-induced plasmin generation. Using surface plasmon resonance, CFDNA bound plasmin with a Kd value of 4.2±0.3 µmol/L, and increasing concentrations of CFDNA impaired plasmin-mediated degradation of fibrin clots via the formation of a nonproductive ternary complex between plasmin, CFDNA, and fibrin., Conclusions: Our studies suggest that the increased levels of CFDNA in sepsis impair fibrinolysis by inhibiting plasmin-mediated fibrin degradation, thereby identifying CFDNA as a potential therapeutic target for sepsis treatment., (© 2015 American Heart Association, Inc.)

Background: Family members may wish to be present during resuscitation of loved ones, despite concerns that they may interfere with the resuscitation or experience psychological harm., Methods: We conducted a systematic review to determine whether offering family presence during resuscitation (FPDR) affected patient mortality, resuscitation quality, or family member psychological outcomes. We searched multiple databases up to January 2014 for studies comparing FPDR to usual care. Two reviewers independently assessed eligibility, risk of bias, and extracted data. Data from randomized controlled trial (RCTs) at low or uncertain risk of bias were eligible for pooling. Quality of evidence was assessed using GRADE., Results: Three RCTs evaluated the offering of FPDR in adults, finding no differences in resuscitation duration, prehospital/emergency room mortality (odds ratio [OR] 0.80, 95 % confidence interval [CI] 0.54-1.19), or 28-day mortality (OR 1.24, 95 % CI [0.50-3.03]). Hospital Anxiety and Depression Scale scores for anxiety (mean difference [MD] -0.99, 95 % CI [-1.77, -0.22]) and depression (MD -1.00, 95 % CI [-1.78, -0.23]), along with Impact of Events Scale intrusion score (MD -1.00, 95 % CI [-1.96, -0.03]), were better in family members offered FPDR. One RCT evaluated FPDR in pediatric patients, finding no mortality differences at 28 days (OR 0.30; 95 % CI [0.11-0.79]), but did not report psychological outcomes in family members., Conclusions: Moderate-quality evidence suggests the offering of FPDR does not affect adult resuscitation outcomes and may improve family member psychological outcomes. Low-quality evidence suggests FPDR does not affect pediatric resuscitation outcomes. The generalizability of these findings outside the prehospital and emergency room setting is limited due to the absence of trials in other health care settings.

A rapid and accurate method to identify severe sepsis patients at high risk of death is critically needed for clinical practice. In a recent study, the concentration of cell-free DNA (cfDNA) in blood was found to be a prognostic indicator for ICU mortality in patients with severe sepsis. However, current DNA quantification techniques are time-consuming and involve extensive sample preparation. In this paper, we demonstrate a low-cost microfluidic device capable of rapid quantification of cfDNA in a small droplet (<10 μl) of blood plasma and whole blood in 5 min using only electrical power. The cfDNA in samples is selectively labeled by PicoGreen and is extracted and concentrated by electrophoresis into a gel by application of a DC potential of 9 V. This device has potential as a prognostic tool for early and rapid assessment of septic patients.