Social determinants of health and sepsis: a case-control study.

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.

RéSUMé: OBJECTIF: Nous avons cherché à déterminer si les déterminants sociaux de la santé (DSS) étaient associés à l'apparition de sepsis et à évaluer les différences entre les personnes vivant dans des quartiers systématiquement défavorisés et celles vivant à l'extérieur de ces quartiers. MéTHODE: Nous avons mené une étude cas témoins monocentrique portant sur 300 patient·es adultes sélectionné·es au hasard (100 personnes atteintes de sepsis et 200 témoins sans sepsis) admis·es au service des urgences d'un grand hôpital universitaire de soins tertiaires à Hamilton, ON, Canada. Nous avons recueilli des données démographiques et un ensemble limité de variables de DSS, y compris le revenu des ménages du quartier, les antécédents de tabagisme, le soutien social et les antécédents de troubles liés à l'alcool. Nous avons analysé les données de l'étude à l'aide de modèles de régression logistique multivariés. RéSULTATS: L'étude a inclus 100 patient·es atteint·es de sepsis avec un âge médian [écart interquartile (ÉIQ)] de 75 [58-84] ans et 200 patient·es sans sepsis avec un âge médian [ÉIQ] de 72 [60-83] ans. Les facteurs significativement associés au sepsis comprenaient l'arrivée en ambulance, l'absence de médecin de famille, un score Hamilton Early Warning Score plus élevé et des antécédents enregistrés de dyslipidémie. D'importantes variables de DSS, telles que le revenu individuel et du ménage et la race, n'étaient pas disponibles dans le dossier médical. Chez les personnes dont les DSS étaient disponibles dans leur dossier médical, aucun DSS n'était significativement associé au sepsis. Néanmoins, comparativement à leur proportion dans la population de Hamilton, le taux de cas de sepsis et de décès dus au sepsis était environ deux fois plus élevé chez les personnes vivant dans des quartiers systématiquement défavorisés. CONCLUSION: Cette étude a révélé le manque de données disponibles sur les DSS dans les dossiers de santé électroniques. Bien qu'il n'y ait pas d'association entre les variables disponibles et le sepsis, nous avons constaté un taux plus élevé de cas de sepsis et de décès dus à la septicémie chez les personnes vivant dans des quartiers systématiquement défavorisés. L'inclusion des DSS dans les dossiers de santé électroniques est cruciale pour étudier leur effet sur le risque de sepsis et pour dispenser des soins équitables.

Topical Versus Intravenous Tranexamic Acid in Patients Undergoing Cardiac Surgery: The DEPOSITION Randomized Controlled Trial.

BACKGROUND: Although intravenous tranexamic acid is used in cardiac surgery to reduce bleeding and transfusion, topical tranexamic acid results in lower plasma concentrations compared to 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 in 11 of 1628 patients (0.7%) in the intravenous group (absolute risk difference, -0.5%; 95% CI, -0.9 to 0.03; P = .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 to 11.5; P = .007). The absolute risk difference in transfusion of ≥4 units of red blood cells in the topical group compared to the intravenous group was 8.2% (95% CI, 3.4 to 12.9). CONCLUSIONS: Among patients having cardiac surgery, topical administration of tranexamic acid resulted in an 8.3% absolute increase in transfusion without reducing the incidence of seizure, compared to intravenous tranexamic acid.

FLUID trial: a hospital-wide open-label cluster cross-over pragmatic comparative effectiveness randomised pilot trial comparing normal saline to Ringer's lactate.

OBJECTIVES: Normal saline (NS) and Ringer's lactate (RL) are the most common crystalloids used for fluid therapy. Despite evidence of possible harm associated with NS (eg, hyperchloremic metabolic acidosis, impaired kidney function and death), few large multi-centre randomised trials have evaluated the effect of these fluids on clinically important outcomes. We conducted a pilot trial to explore the feasibility of a large trial powered for clinically important outcomes. DESIGN: FLUID was a pragmatic pilot cluster randomised cross-over trial. SETTING: Four hospitals in the province of Ontario, Canada PARTICIPANTS: All hospitalised adult and paediatric patients with an incident admission to the hospital over the course of each study period. INTERVENTIONS: A hospital wide policy/strategy which stocked either NS or RL throughout the hospital for 12 weeks before crossing over to the alternate fluid for the subsequent 12 weeks. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary feasibility outcome was study fluid protocol adherence. Secondary feasibility outcomes included time to Research Ethics Board (REB) approval and trial initiation. Primary (composite of death or re-admission to hospital in first 90 days of index hospitalisation) and secondary clinical outcomes were analysed descriptively. RESULTS: Among 24 905 included patients, mean age 59.1 (SD 20.5); 13 977 (56.1%) were female and 21 150 (85.0%) had medical or surgical admitting diagnoses. Overall, 96 821 L were administered in the NS arm, and 78 348 L in the RL arm. Study fluid adherence to NS and RL was 93.7% (site range: 91.6%-98.0%) and 79.8% (site range: 72.5%-83.9%), respectively. Time to REB approval ranged from 2 to 48 days and readiness for trial initiation from 51 to 331 days. 5544 (22.3%) patients died or required hospital re-admission in the first 90 days. CONCLUSIONS: The future large trial is feasible. Anticipating and addressing logistical challenges during the planning stages will be imperative. TRIAL REGISTRATION NUMBER: NCT02721485.

Cross-immunity against SARS-COV-2 variants of concern in naturally infected critically ill COVID-19 patients.

Critically ill patients infected with SARS-CoV-2 display adaptive immunity, but it is unknown if they develop cross-reactivity to variants of concern (VOCs). We profiled cross-immunity against SARS-CoV-2 VOCs in naturally infected, non-vaccinated, critically ill COVID-19 patients. Wave-1 patients (wild-type infection) were similar in demographics to Wave-3 patients (wild-type/alpha infection), but Wave-3 patients had higher illness severity. Wave-1 patients developed increasing neutralizing antibodies to all variants, as did patients during Wave-3. Wave-3 patients, when compared to Wave-1, developed more robust antibody responses, particularly for wild-type, alpha, beta and delta variants. Within Wave-3, neutralizing antibodies were significantly less to beta and gamma VOCs, as compared to wild-type, alpha and delta. Patients previously diagnosed with cancer or chronic obstructive pulmonary disease had significantly fewer neutralizing antibodies. Naturally infected ICU patients developed adaptive responses to all VOCs, with greater responses in those patients more likely to be infected with the alpha variant, versus wild-type.

Survey of Physiotherapy Practice in Ontario Cardiac Surgery Intensive Care Units.

Purpose: This article describes current physiotherapy practice for critically ill adult patients requiring prolonged stays in critical care (> 3 d) after complicated cardiac surgery in Ontario. Method: We distributed an electronic, self-administered 52-item survey to 35 critical care physiotherapists who treat adult cardiac surgery patients at 11 cardiac surgical sites. Pilot testing and clinical sensibility testing were conducted beforehand. Participants were sent four email reminders. Results: The response rate was 80% (28/35). The median reported number of cardiac surgeries performed per week was 30 (interquartile range [IQR] 10), with a median number of 14.5 (IQR 4) cardiac surgery beds per site. Typical reported caseloads ranged from 6 to 10 patients per day per therapist, and 93% reported that they had initiated physiotherapy with patients once they were clinically stable in the intensive care unit. Of 28 treatments, range of motion exercises (27; 96.4%), airway clearance techniques (26; 92.9%), and sitting at the edge of the bed (25; 89.3%) were the most common. Intra-aortic balloon pump and extracorporeal membrane oxygenation appeared to limit physiotherapy practice. Use of outcome measures was limited. Conclusions: Physiotherapists provide a variety of interventions to critically ill cardiac surgery patients. Further evaluation of the limited use of outcome measures in the cardiac surgical intensive care unit is warranted.

Objectif : décrire la pratique actuelle de la physiothérapie auprès des patients adultes gravement malades de l'Ontario qui doivent séjourner plus de trois jours en soins intensifs après une opération cardiaque complexe. Méthodologie : distribution d'un sondage électronique autoadministré de 52 questions à 35 physiothérapeutes en soins intensifs qui soignent des patients après une opération cardiaque dans 11 établissements de chirurgie cardiaque. Les chercheurs ont procédé à des essais pilotes et à des tests de sensibilité clinique auparavant. Les participants ont reçu quatre rappels par courriel. Résultats : le taux de réponse s'élevait à 80 % (28 sur 35). Selon la médiane, 30 (plage interquartile [PIQ] de 10) chirurgies cardiaques étaient effectuées par semaine, pour une médiane de 14,5 (PIQ de 4) lits en chirurgie cardiaque par établissement. La charge de travail habituelle se situait entre six et dix patients par thérapeute par jour, et 93 % ont déclaré entreprendre la physiothérapie avec les patients dont l'état s'était stabilisé à l'unité de soins intensifs. Sur 28 traitements, les plus courants étaient des exercices d'amplitude (27 sur 28, 96,4 %), des techniques de dégagement des voies respiratoires (26 sur 28, 92,9 %) et la capacité de s'asseoir au bord du lit (25 sur 28, 89,3 %). Le ballon de contrepulsion intra-aortique et l'oxygénation par membrane extracorporelle semblaient limiter la pratique de la physiothérapie. L'utilisation des mesures de résultats cliniques était limitée. Conclusion : les physiothérapeutes proposent diverses interventions aux patients gravement malades après une opération cardiaque. Une évaluation plus approfondie du recours limité aux mesures de résultats cliniques à l'unité de soins intensifs de cardiologie s'impose.

The experiences of cardiac surgery critical care clinicians with in-bed cycling in adult patients undergoing complex cardiac surgery.

PURPOSE: In-bed cycling is a novel modality that permits the early initiation of rehabilitation in the intensive care unit. We explored clinicians' experiences and perceptions of in-bed cycling with critically ill cardiac surgery patients. MATERIALS AND METHODS: We used an interpretive description methodology. All critical care clinicians who had been present for at least 2 cycling sessions were eligible. Data were collected using semi-structured, audio-recorded, face-to-face interviews transcribed verbatim. Content analysis was used to identify themes. RESULTS: Nine clinicians were interviewed. Our sample was predominantly female (77.8%) with a median [IQR] age of 40 [21.5] years. Critical care experience ranged from <5 years to ≥30 years. Acceptability was influenced by previous cycling experiences, identifying the "ideal" patient, and the timing of cycling within a patient's recovery. Facilitators included striving towards a common goal and feeling confident in the method. Barriers included inadequate staffing, bike size, and the time to deliver cycling. CONCLUSIONS: Clinicians supported the use of in-bed cycling. Concerns included appropriate patient selection and timing of the intervention. Teamwork was integral to successful cycling. Strategies to overcome the identified barriers may assist with successful cycling implementation in other critical care environments.IMPLICATIONS FOR REHABILITATIONIn-bed cycling is a relatively novel rehabilitation modality that can help initiate physical rehabilitation earlier in a patient's recovery and reduce the iatrogenic effects of prolonged admissions to an intensive care unit.Clinicians found in-bed cycling to be an acceptable intervention with a population of critically ill cardiac surgery patients.Teamwork and interprofessional communication are important considerations for successful uptake of a relatively new rehabilitation modality.Identified barriers to in-bed cycling can assist with developing strategies to encourage cycling uptake in similar critical care environments.

CardiO Cycle: a pilot feasibility study of in-bed cycling in critically ill patients post cardiac surgery.

BACKGROUND: In-bed cycling is a novel modality for the initiation of early mobilization in the intensive care unit. No study has investigated its use in the critically ill, off-track post cardiac surgery population. Before conducting an effectiveness trial, feasibility data are needed. The aim of this study was to determine the feasibility of in-bed cycling in a population of off-track cardiac surgery patients. METHODS: We conducted a prospective feasibility study in a 16-bed adult cardiac surgery intensive care unit in Ontario, Canada. Previously ambulatory adults (≥ 18 years) who were mechanically ventilated for ≥ 72 h were enrolled within 3 to 7 days post cardiac surgery. Twenty minutes of in-bed cycling was delivered by ICU physiotherapists 5 days/week. The primary outcome, feasibility, was the percent of patient-cycling sessions that occurred when cycling was appropriate. The secondary outcome was cycling safety, measured as cycling discontinuation due to predetermined adverse events. RESULTS: We screened 2074 patients, 29 met eligibility criteria, and 23 (92%) consented. Patients were male (78.26%) with a median [IQR] age of 76 [11] years, underwent isolated coronary bypass (39.1%), and had a median EuroScore II of 5.4 [7.8]. The mean (SD) time post-surgery to start of cycling was 5.9 (1.4) days. Patients were cycled on 80.5% (136/169) of eligible days, with limited physiotherapy staffing accounting for 48.5% of the missed patient-cycling sessions. During 136 sessions of cycling, 3 adverse events occurred in 3 individual patients. The incidence of an adverse event was 2.2 per 100 patient-cycling sessions (95% CI 0.50, 6.4). CONCLUSIONS: In-bed cycling with critically ill cardiac surgery patients is feasible with adequate physiotherapy staffing and appears to be safe. Future studies are needed to determine the effectiveness of this intervention in a larger sample. TRIAL REGISTRATION: This trial was registered with Clinicaltrials.gov ( NCT02976415 ). Registered November 29, 2016.

Social determinants of health associated with the development of sepsis in adults: a scoping review protocol.

INTRODUCTION: Sepsis, the life-threatening immune response to infection, affects millions of people annually. Understanding of the factors associated with the development of sepsis is crucial for improving population health and public health efforts; in particular, literature exploring the relationship between sepsis and social determinants of health is lacking. This review seeks to establish and amalgamate existing evidence of the relationships between sepsis and the following social determinants: frailty, registration with a family physician, mental illness, alcohol abuse, social support levels, smoking status, illicit drug use disorders, socioeconomic status, gender and race/ethnicity. METHODS AND ANALYSIS: This study will analyse qualitative and quantitative studies using standard processes. The selected social determinants of health and their potential link to adult sepsis will be analysed separately under distinct headings. Findings will be consolidated in a final discussion. PubMed and Medline will be searched for articles published between 1970 and 2020 using search strings combining 'sepsis' and other variations, such as 'septicaemia' with each social determinant of interest. 'Sepsis' and at least one social determinant of interest must be present in a study's title for inclusion in the review; the results of the initial search will be filtered based on predetermined inclusion and exclusion criteria. Evidence from this scoping review will provide information on the impact of social determinants of health on the risk of developing adult sepsis, which can inform clinicians of the various risk factors to consider when admitting patients. ETHICS AND DISSEMINATION: Approval from a research ethics board is not needed for this amalgamation of information from studies for which the primary investigators have obtained their own, respective ethics board approval. Once completed, the review will be submitted for publication in a peer-reviewed journal, and findings will be presented in local and national forums.

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

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

Sialidase down-regulation reduces non-HDL cholesterol, inhibits leukocyte transmigration, and attenuates atherosclerosis in ApoE knockout mice.

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 (Neu1hypoApoe-/-). 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 Neu1hypoApoe-/- mice significantly increased atherosclerotic lesion development and had no effect on serum lipoprotein levels. Moreover, Neu1hypoApoe-/- 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.

Low-density lipoprotein (LDL)-dependent uptake of Gram-positive lipoteichoic acid and Gram-negative lipopolysaccharide occurs through LDL receptor.

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.

Body temperature and mouse scoring systems as surrogate markers of death in cecal ligation and puncture sepsis.

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.

Allogeneic Mesenchymal Stem Cells for Treatment of AKI after Cardiac Surgery.

AKI after cardiac surgery remains strongly associated with mortality and lacks effective treatment or prevention. Preclinical studies suggest that cell-based interventions may influence functional recovery. We conducted a phase 2, randomized, double-blind, placebo-controlled trial in 27 centers across North America to determine the safety and efficacy of allogeneic human mesenchymal stem cells (MSCs) in reducing the time to recovery from AKI after cardiac surgery. We randomized 156 adult subjects undergoing cardiac surgery with evidence of early AKI to receive intra-aortic MSCs (AC607; n=67) or placebo (n=68). The primary outcome was the time to recovery of kidney function defined as return of postintervention creatinine level to baseline. The median time to recovery of kidney function was 15 days with AC607 and 12 days with placebo (25th, 75th percentile range, 10-29 versus 6-21, respectively; hazard ratio, 0.81; 95% confidence interval, 0.53 to 1.24; P=0.32). We did not detect a significant difference between groups in 30-day all-cause mortality (16.7% with AC607; 11.8% with placebo) or dialysis (10.6% with AC607; 7.4% with placebo). At follow-up, 12 patients who received AC607 and six patients who received placebo had died. Rates of other adverse events did not differ between groups. In these patients with AKI after cardiac surgery, administration of allogeneic MSCs did not decrease the time to recovery of kidney function. Our results contrast with those in preclinical studies and provide important information regarding the potential effects of MSCs in this setting.

Differential Expression of PCSK9 Modulates Infection, Inflammation, and Coagulation in a Murine Model of Sepsis.

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.

Delayed but not Early Treatment with DNase Reduces Organ Damage and Improves Outcome in a Murine Model of Sepsis.

Sepsis is characterized by systemic activation of coagulation and inflammation in response to microbial infection. Although cell-free DNA (cfDNA) released from activated neutrophils has antimicrobial properties, it may also exert harmful effects by activating coagulation and inflammation. The authors aimed to determine whether deoxyribonuclease (DNase) administration reduces cfDNA levels, attenuates coagulation and inflammation, suppresses organ damage, and improves outcome in a cecal ligation and puncture (CLP) model of polymicrobial sepsis. Healthy C57Bl/6 mice were subjected to CLP, a surgical procedure involving two punctures of the ligated cecum, or sham surgery (no ligation/puncture). Mice were given DNase or saline by intraperitoneal injection 2, 4, or 6 h after surgery. Two hours after treatment, organs were harvested and plasma levels of cfDNA, interleukin-6 (IL-6), IL-10, thrombin-antithrombin complexes, lung myeloperoxidase, creatinine, alanine transaminase, and bacterial load were quantified. Survival studies were also performed. The CLP-operated mice had rapid time-dependent elevations in cfDNA that correlated with elevations in IL-6, IL-10, and thrombin-antithrombin complexes and had organ damage in the lungs and kidneys. Administration of DNase at 2 h after CLP resulted in increased IL-6 and IL-10 levels and organ damage in the lungs and kidneys. In contrast, DNase administration at 4 or 6 h after CLP resulted in reduced cfDNA and IL-6 levels, increased IL-10, and suppressed organ damage and bacterial dissemination. Deoxyribonuclease administration every 6 h after CLP also rescued mice from death. Our studies are the first to demonstrate that delayed but not early administration of DNase may be protective in experimental sepsis.

The effect of rapid response teams on end-of-life care: a retrospective chart review.

BACKGROUND: A subset of critically ill patients have end-of-life (EOL) goals that are unclear. Rapid response teams (RRTs) may aid in the identification of these patients and the delivery of their EOL care. OBJECTIVES: To characterize the impact of RRT discussion on EOL care, and to examine how a preprinted order (PPO) set for EOL care influenced EOL discussions and outcomes. METHODS: A single-centre retrospective chart review of all RRT calls (January 2009 to December 2010) was performed. The effect of RRT EOL discussions and the effect of a hospital-wide PPO set on EOL care was examined. Charts were from the Ontario Ministry of Health and Long-Term Care Critical Care Information Systemic database, and were interrogated by two reviewers. RESULTS: In patients whose EOL status changed following RRT EOL discussion, there were fewer intensive care unit (ICU) transfers (8.4% versus 17%; P<0.001), decreased ICU length of stay (5.8 days versus 20 days; P=0.08), increased palliative care consultations (34% versus 5.3%; P<0.001) and an increased proportion who died within 24 h of consultation (25% versus 8.3%; P<0.001). More patients experienced a change in EOL status following the introduction of an EOL PPO, from 20% (before) to 31% (after) (P<0.05). CONCLUSIONS: A change in EOL status following RRT-led EOL discussion was associated with reduced ICU transfers and enhanced access to palliative care services. Further study is required to identify and deconstruct barriers impairing timely and appropriate EOL discussions.

Syndecan-1 in the mouse parietal peritoneum microcirculation in inflammation.

BACKGROUND: The heparan sulfate proteoglycan syndecan-1 (CD138) was shown to regulate inflammatory responses by binding chemokines and cytokines and interacting with adhesion molecules, thereby modulating leukocyte trafficking to tissues. The objectives of this study were to examine the expression of syndecan-1 and its role in leukocyte recruitment and chemokine presentation in the microcirculation underlying the parietal peritoneum. METHODS: Wild-type BALB/c and syndecan-1 null mice were stimulated with an intraperitoneal injection of Staphylococcus aureus LTA, Escherichia coli LPS or TNFα and the microcirculation of the parietal peritoneum was examined by intravital microscopy after 4 hours. Fluorescence confocal microscopy was used to examine syndecan-1 expression in the peritoneal microcirculation using fluorescent antibodies. Blocking antibodies to adhesion molecules were used to examine the role of these molecules in leukocyte-endothelial cell interactions in response to LTA. To determine whether syndecan-1 co-localizes with chemokines in vivo, fluorescent antibodies to syndecan-1 were co-injected intravenously with anti-MIP-2 (CXCL2), anti-KC (CXCL1) or anti-MCP-1 (CCL2). RESULTS AND CONCLUSION: Syndecan-1 was localized to the subendothelial region of peritoneal venules and the mesothelial layer. Leukocyte rolling was significantly decreased with LPS treatment while LTA and TNFα significantly increased leukocyte adhesion compared with saline control. Leukocyte-endothelial cell interactions were not different in syndecan-1 null mice. Antibody blockade of ß2 integrin (CD18), ICAM-1 (CD54) and VCAM-1 (CD106) did not decrease leukocyte adhesion in response to LTA challenge while blockade of P-selectin (CD62P) abrogated leukocyte rolling. Lastly, MIP-2 expression in the peritoneal venules was not dependent on syndecan-1 in vivo. Our data suggest that syndecan-1 is expressed in the parietal peritoneum microvasculature but does not regulate leukocyte recruitment and is not necessary for the presentation of the chemokine MIP-2 in this tissue.

Development of a murine model of early sepsis in diet-induced obesity.

Sepsis, a global health issue, is the most common cause of mortality in the intensive care unit. The aim of this study was to develop a new model of sepsis that investigates the impact of prolonged western diet (WD) induced obesity on the response to early sepsis. Male C57BL/6 mice were fed either a high fat WD or normal chow diet (NCD) for 6, 15, or 27 weeks. Septic obese mice at 15 and 27 weeks had significantly lower levels of lung myeloperoxidase (26.3 ± 3.80 U/mg tissue) compared to age matched ad lib (44.1 ± 2.86 U/mg tissue) and diet restricted (63.2 ± 5.60 U/mg tissue) controls. Low levels of lung inflammation were not associated with changes in hepatic cytokines and oxidative stress levels. Obese mice had significantly (P < 0.0001) larger livers compared to controls. Histological examination of the livers demonstrated that WD fed mice had increased inflammation with pronounced fat infiltration, steatosis, and hepatocyte ballooning. Using this model of prolonged exposure to high fat diet we have data that agree with recent clinical observations suggesting obese individuals are protected from sepsis-induced lung injury. This model will allow us to investigate the links between damage to the hepatic microcirculation, immune response, and lung injury.

Alpha-1 acid glycoprotein reduces hepatic leukocyte recruitment in murine models of either early endotoxemia or early sepsis.

OBJECTIVE: To characterize the effect of systemically administered AGP on early leukocyte recruitment in the livers of endotoxemic or septic mice and to determine whether this is influenced by LPS sequestration. METHODS: Endotoxemia was induced in C57Bl/6 mice via intraperitoneal injection of LPS. Sepsis was induced in mice by cecal ligation and perforation. AGP (165 mg/kg) or saline (20 mL/kg) or HAS (200 mg/kg) was administered immediately after surgery or LPS injection and the hepatic microcirculation was examined by intravital microscopy at four hour. RESULTS: Leukocyte adhesion in the PSV was reduced by treatment with AGP in mice subjected to either LPS or CLP protocols compared to either saline or HAS treatment. AGP-treated mice also had significantly higher sinusoidal flow in both models. Pre-incubation of LPS with AGP reduced the ability of LPS to recruit leukocytes to the liver microcirculation. CONCLUSIONS: AGP was more effective in limiting hepatic inflammation and maintaining perfusion than saline or HAS, in both endotoxemic and septic mice. AGP sequestration of LPS may contribute to its anti-inflammatory effects.