Browsing by Subject "Sepsis"
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Item A new perspective on NO pathway in sepsis and ADMA lowering as a potential therapeutic approach(BMC, 2022-08-12) Singh, Jaipal; Lee, Young; Kellum, John A.; Cellular and Integrative Physiology, School of MedicineThe nitric oxide pathway plays a critical role in vascular homeostasis. Increased levels of systemic nitric oxide (NO) are observed in preclinical models of sepsis and endotoxemia. This has led to the postulation that vasodilation by inducible nitric oxide synthase (iNOS) generated NO may be a mechanism of hypotension in sepsis. However, contrary to the expected pharmacological action of a nitric oxide synthase (NOS) inhibitor, clinical studies with L-NAME produced adverse cardiac and pulmonary events, and higher mortality in sepsis patients. Thus, the potential adverse effects of NO in human sepsis and shock have not been fully established. In recent years, the emerging new understanding of the NO pathway has shown that an endogenously produced inhibitor of NOS, asymmetric dimethylarginine (ADMA), a host response to infection, may play an important role in the pathophysiology of sepsis as well as organ damage during ischemia-reperfusion. ADMA induces microvascular dysfunction, proinflammatory and prothrombotic state in endothelium, release of inflammatory cytokines, oxidative stress and mitochondrial dysfunction. High levels of ADMA exist in sepsis patients, which may produce adverse effects like those observed with L-NAME. Several studies have demonstrated the association of plasma ADMA levels with mortality in sepsis patients. Preclinical studies in sepsis and ischemia-reperfusion animal models have shown that lowering of ADMA reduced organ damage and improved survival. The clinical finding with L-NAME and the preclinical research on ADMA "bed to bench" suggest that ADMA lowering could be a potential therapeutic approach to attenuate progressive organ damage and mortality in sepsis. Testing of this approach is now feasible by using the pharmacological molecules that specifically lower ADMA.Item Cardiac Metabolism in Sepsis(MDPI, 2021-12-06) Kawaguchi, Satoshi; Okada, Motoi; Anatomy, Cell Biology and Physiology, School of MedicineThe mechanism of sepsis-induced cardiac dysfunction is believed to be different from that of myocardial ischemia. In sepsis, chemical mediators, such as endotoxins, cytokines, and nitric oxide, cause metabolic abnormalities, mitochondrial dysfunction, and downregulation of β-adrenergic receptors. These factors inhibit the production of ATP, essential for myocardial energy metabolism, resulting in cardiac dysfunction. This review focuses on the metabolic changes in sepsis, particularly in the heart. In addition to managing inflammation, interventions focusing on metabolism may be a new therapeutic strategy for cardiac dysfunction due to sepsis.Item Cardiac Output Monitoring Managing Intravenous Therapy (COMMIT) to Treat Emergency Department Patients with Sepsis(Wolters Kluwer, 2016-08) Hou, Peter C.; Filbin, Michael R.; Napoli, Anthony; Feldman, Joseph; Pang, Peter S.; Sankoff, Jeffrey; Lo, Bruce M.; Dickey-White, Howard; Birkhahn, Robert H.; Shapiro, Nathan I.; Department of Emergency Medicine, IU School of MedicineOBJECTIVE: Fluid responsiveness is proposed as a physiology-based method to titrate fluid therapy based on preload dependence. The objectives of this study were to determine if a fluid responsiveness protocol would decrease progression of organ dysfunction, and a fluid responsiveness protocol would facilitate a more aggressive resuscitation. METHODS: Prospective, 10-center, randomized interventional trial. INCLUSION CRITERIA: suspected sepsis and lactate 2.0 to 4.0 mmol/L. Exclusion criteria (abbreviated): systolic blood pressure more than 90 mmHg, and contraindication to aggressive fluid resuscitation. INTERVENTION: fluid responsiveness protocol using Non-Invasive Cardiac Output Monitor (NICOM) to assess for fluid responsiveness (>10% increase in stroke volume in response to 5 mL/kg fluid bolus) with balance of a liter given in responsive patients. CONTROL: standard clinical care. OUTCOMES: primary-change in Sepsis-related Organ Failure Assessment (SOFA) score at least 1 over 72 h; secondary-fluids administered. Trial was initially powered at 600 patients, but stopped early due to a change in sponsor's funding priorities. RESULTS: Sixty-four patients were enrolled with 32 in the treatment arm. There were no significant differences between arms in age, comorbidities, baseline vital signs, or SOFA scores (P > 0.05 for all). Comparing treatment versus Standard of Care-there was no difference in proportion of increase in SOFA score of at least 1 point (30% vs. 33%) (note bene underpowered, P = 1.0) or mean preprotocol fluids 1,050 mL (95% confidence interval [CI]: 786-1,314) vs. 1,031 mL (95% CI: 741-1,325) (P = 0.93); however, treatment patients received more fluids during the protocol (2,633 mL [95% CI: 2,264-3,001] vs. 1,002 mL [95% CI: 707-1,298]) (P < 0.001). CONCLUSIONS: In this study of a "preshock" population, there was no change in progression of organ dysfunction with a fluid responsiveness protocol. A noninvasive fluid responsiveness protocol did facilitate delivery of an increased volume of fluid. Additional properly powered and enrolled outcomes studies are needed.Item Characteristics and outcomes of patients with sepsis who had cortisol level measurements or received hydrocortisone during their intensive care unit management: A retrospective single center study(Sage, 2023-01-03) Rivas, Marcella; Motes, Arunee; Ismail, Amr; Yang, Shengping; Sotello, David; Arevalo, Meily; Vutthikraivit, Wasawat; Suchartlikitwong, Sakolwan; Carrasco, Cynthia; Iwuji, Kenneth; Pachariyanon, Pavida; Jaroudi, Sarah; Thavaraputta, Subhanudh; Nugent, Kenneth; Medicine, School of MedicineObjectives: The current guidelines for managing patients with sepsis include the early cultures, administration of antibiotics, and fluid resuscitation. Several clinical trials have tried to determine whether or not the administration of corticosteroids improves outcomes in these patients. This study analyzed the characteristics of a large group of critically ill patients who either had cortisol levels drawn during their intensive care unit management or had hydrocortisone administered during their management. Methods: A list of patients who had cortisol levels measured or who had hydrocortisone administered empirically for the treatment of sepsis was identified by the medical record department at University Medical Center in Lubbock, Texas. The primary outcome was in-hospital mortality. Secondary outcomes included the need for mechanical ventilation, the need for renal replacement therapy, the need for vasopressors, length of stay, and the development of nosocomial infections. Results: This study included 351 patients, including 194 women (55.3%). The mean age was 62.9 ± 16.1 years. The mean admission SOFA score was 9.3 ± 3.63, the mean APACHE 2 score was 18.15 ± 7.7, and the mean lactic acid level was 3.8 ± 4.0 mmol/L. One hundred sixty-two patients required intubation, 262 required vasopressors, 215 developed acute kidney injury, and 319 had cortisol levels measured. The mean length of stay was 11.5 ± 13.7 days; the mortality rate was 32.2%. Multiple variable analysis demonstrated that higher cortisol levels were associated with increased mortality (44.1% if cortisol ⩾20 µg/dL versus 17.5% if cortisol <20 µg/dL). One hundred forty-five patients received corticosteroids, and multivariable analysis demonstrated that these patients had increased mortality (40.0% versus 26.7%). Conclusion: In this study, higher cortisol levels were associated with increased mortality. The administration of hydrocortisone was associated with increased mortality possibly reflecting the use of this medication in patients who had a higher likelihood of poor outcomes.Item Cutaneous Burn Injury Modulates Urinary Antimicrobial Peptide Responses and the Urinary Microbiome(Lippincott, Williams & Wilkins, 2017-06) Plichta, Jennifer K.; Holmes, Casey J.; Nienhouse, Vanessa; Puszynski, Michelle; Gao, Xiang; Dong, Qunfeng; Lin, Huaiying; Sinacore, James; Zilliox, Michael; Toh, Evelyn; Nelson, David E.; Gamelli, Richard L.; Radek, Katherine A.; Microbiology and Immunology, School of MedicineOBJECTIVES: Characterization of urinary bacterial microbiome and antimicrobial peptides after burn injury to identify potential mechanisms leading to urinary tract infections and associated morbidities in burn patients. DESIGN: Retrospective cohort study using human urine from control and burn subjects. SETTING: University research laboratory. PATIENTS: Burn patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Urine samples from catheterized burn patients were collected hourly for up to 40 hours. Control urine was collected from "healthy" volunteers. The urinary bacterial microbiome and antimicrobial peptide levels and activity were compared with patient outcomes. We observed a significant increase in urinary microbial diversity in burn patients versus controls, which positively correlated with a larger percent burn and with the development of urinary tract infection and sepsis postadmission, regardless of age or gender. Urinary psoriasin and β-defensin antimicrobial peptide levels were significantly reduced in burn patients at 1 and 40 hours postadmission. We observed a shift in antimicrobial peptide hydrophobicity and activity between control and burn patients when urinary fractions were tested against Escherichia coli and Enterococcus faecalis urinary tract infection isolates. Furthermore, the antimicrobial peptide activity in burn patients was more effective against E. coli than E. faecalis. Urinary tract infection-positive burn patients with altered urinary antimicrobial peptide activity developed either an E. faecalis or Pseudomonas aeruginosa urinary tract infection, suggesting a role for urinary antimicrobial peptides in susceptibility to select uropathogens. CONCLUSIONS: Our data reveal potential links for urinary tract infection development and several morbidities in burn patients through alterations in the urinary microbiome and antimicrobial peptides. Overall, this study supports the concept that early assessment of urinary antimicrobial peptide responses and the bacterial microbiome may be used to predict susceptibility to urinary tract infections and sepsis in burn patients.Item Cutaneous Burn Injury Promotes Shifts in the Bacterial Microbiome in Autologous Donor Skin: Implications for Skin Grafting Outcomes(Wolters Kluwer, 2017-10) Plichta, Jennifer K.; Gao, Xiang; Lin, Huaiying; Dong, Qunfeng; Toh, Evelyn; Nelson, David E.; Gamelli, Richard L.; Grice, Elizabeth A.; Radek, Katherine A.; Microbiology and Immunology, School of MedicineINTRODUCTION: The cutaneous microbiome maintains skin barrier function, regulates inflammation, and stimulates wound-healing responses. Burn injury promotes an excessive activation of the cutaneous and systemic immune response directed against commensal and invading pathogens. Skin grafting is the primary method of reconstructing full-thickness burns, and wound infection continues to be a significant complication. METHODS: In this study, the cutaneous bacterial microbiome was evaluated and subsequently compared to patient outcomes. Three different full-thickness skin specimens were assessed: control skin from non-burned subjects; burn margin from burn patients; and autologous donor skin from the same cohort of burn patients. RESULTS: We observed that skin bacterial community structure of burn patients was significantly altered compared with control patients. We determined that the unburned autologous donor skin from burn patients exhibits a microbiome similar to that of the burn margin, rather than unburned controls, and that changes in the cutaneous microbiome statistically correlate with several post-burn complications. We established that Corynebacterium positively correlated with burn wound infection, while Staphylococcus and Propionibacterium negatively correlated with burn wound infection. Both Corynebacterium and Enterococcus negatively correlated with the development of sepsis. CONCLUSIONS: This study identifies distinct differences in the cutaneous microbiome between burn subjects and unburned controls, and ascertains that select bacterial taxa significantly correlate with several comorbid complications of burn injury. These preliminary data suggest that grafting donor skin exhibiting bacterial dysbiosis may augment infection and/or graft failure and sets the foundation for more in-depth and mechanistic analyses in presumably "healthy" donor skin from patients requiring skin grafting procedures.Item Derivation, Validation, and Clinical Relevance of a Pediatric Sepsis Phenotype With Persistent Hypoxemia, Encephalopathy, and Shock(Wolters Kluwer, 2023) Sanchez-Pinto, L. Nelson; Bennett, Tellen D.; Stroup, Emily K.; Luo, Yuan; Atreya, Mihir; Bubeck Wardenburg, Juliane; Chong, Grace; Geva, Alon; Faustino, E. Vincent S.; Farris, Reid W.; Hall, Mark W.; Rogerson, Colin; Shah, Sareen S.; Weiss, Scott L.; Khemani, Robinder G.; Pediatrics, School of MedicineObjectives: Untangling the heterogeneity of sepsis in children and identifying clinically relevant phenotypes could lead to the development of targeted therapies. Our aim was to analyze the organ dysfunction trajectories of children with sepsis-associated multiple organ dysfunction syndrome (MODS) to identify reproducible and clinically relevant sepsis phenotypes and determine if they are associated with heterogeneity of treatment effect (HTE) to common therapies. Design: Multicenter observational cohort study. Setting: Thirteen PICUs in the United States. Patients: Patients admitted with suspected infections to the PICU between 2012 and 2018. Interventions: None. Measurements and main results: We used subgraph-augmented nonnegative matrix factorization to identify candidate trajectory-based phenotypes based on the type, severity, and progression of organ dysfunction in the first 72 hours. We analyzed the candidate phenotypes to determine reproducibility as well as prognostic, therapeutic, and biological relevance. Overall, 38,732 children had suspected infection, of which 15,246 (39.4%) had sepsis-associated MODS with an in-hospital mortality of 10.1%. We identified an organ dysfunction trajectory-based phenotype (which we termed persistent hypoxemia, encephalopathy, and shock) that was highly reproducible, had features of systemic inflammation and coagulopathy, and was independently associated with higher mortality. In a propensity score-matched analysis, patients with persistent hypoxemia, encephalopathy, and shock phenotype appeared to have HTE and benefit from adjuvant therapy with hydrocortisone and albumin. When compared with other high-risk clinical syndromes, the persistent hypoxemia, encephalopathy, and shock phenotype only overlapped with 50%-60% of patients with septic shock, moderate-to-severe pediatric acute respiratory distress syndrome, or those in the top tier of organ dysfunction burden, suggesting that it represents a nonsynonymous clinical phenotype of sepsis-associated MODS. Conclusions: We derived and validated the persistent hypoxemia, encephalopathy, and shock phenotype, which is highly reproducible, clinically relevant, and associated with HTE to common adjuvant therapies in children with sepsis.Item Derivation, validation, and transcriptomic assessment of pediatric septic shock phenotypes identified through latent profile analyses: Results from a prospective multi-center observational cohort(Research Square, 2023-12-06) Atreya, Mihir R.; Huang, Min; Moore, Andrew R.; Zheng, Hong; Hasin-Brumshtein, Yehudit; Fitzgerald, Julie C.; Weiss, Scott L.; Cvijanovich, Natalie Z.; Bigham, Michael T.; Jain, Parag N.; Schwarz, Adam J.; Lutfi, Riad; Nowak, Jeffrey; Thomas, Neal J.; Quasney, Michael; Dahmer, Mary K.; Baines, Torrey; Haileselassie, Bereketeab; Lautz, Andrew J.; Stanski, Natalja L.; Standage, Stephen W.; Kaplan, Jennifer M.; Zingarelli, Basilia; Sweeney, Timothy E.; Khatri, Purvesh; Sanchez-Pinto, L. Nelson; Kamaleswaran, Rishikesan; Pediatrics, School of MedicineBackground: Sepsis poses a grave threat, especially among children, but treatments are limited due to clinical and biological heterogeneity among patients. Thus, there is an urgent need for precise subclassification of patients to guide therapeutic interventions. Methods: We used clinical, laboratory, and biomarker data from a prospective multi-center pediatric septic shock cohort to derive phenotypes using latent profile analyses. Thereafter, we trained a support vector machine model to assign phenotypes in a hold-out validation set. We tested interactions between phenotypes and common sepsis therapies on clinical outcomes and conducted transcriptomic analyses to better understand the phenotype-specific biology. Finally, we compared whether newly identified phenotypes overlapped with established gene-expression endotypes and tested the utility of an integrated subclassification scheme. Findings: Among 1,071 patients included, we identified two phenotypes which we named 'inflamed' (19.5%) and an 'uninflamed' phenotype (80.5%). The 'inflamed' phenotype had an over 4-fold risk of 28-day mortality relative to those 'uninflamed'. Transcriptomic analysis revealed overexpression of genes implicated in the innate immune response and suggested an overabundance of developing neutrophils, pro-T/NK cells, and NK cells among those 'inflamed'. There was no significant overlap between endotypes and phenotypes. However, an integrated subclassification scheme demonstrated varying survival probabilities when comparing endophenotypes. Interpretation: Our research underscores the reproducibility of latent profile analyses to identify clinical and biologically informative pediatric septic shock phenotypes with high prognostic relevance. Pending validation, an integrated subclassification scheme, reflective of the different facets of the host response, holds promise to inform targeted intervention among those critically ill.Item Detrimental effects of PCSK9 loss-of-function in the pediatric host response to sepsis are mediated through independent influence on Angiopoietin-1(BMC, 2023-06-26) Atreya, Mihir R.; Cvijanovich, Natalie Z.; Fitzgerald, Julie C.; Weiss, Scott L.; Bigham, Michael T.; Jain, Parag N.; Schwarz, Adam J.; Lutfi, Riad; Nowak, Jeffrey; Allen, Geoffrey L.; Thomas, Neal J.; Grunwell, Jocelyn R.; Baines, Torrey; Quasney, Michael; Haileselassie, Bereketeab; Alder, Matthew N.; Lahni, Patrick; Ripberger, Scarlett; Ekunwe, Adesuwa; Campbell, Kyle R.; Walley, Keith R.; Standage, Stephen W.; Pediatrics, School of MedicineBackground: Sepsis is associated with significant mortality. Yet, there are no efficacious therapies beyond antibiotics. PCSK9 loss-of-function (LOF) and inhibition, through enhanced low-density lipoprotein receptor (LDLR) mediated endotoxin clearance, holds promise as a potential therapeutic approach among adults. In contrast, we have previously demonstrated higher mortality in the juvenile host. Given the potential pleiotropic effects of PCSK9 on the endothelium, beyond canonical effects on serum lipoproteins, both of which may influence sepsis outcomes, we sought to test the influence of PCSK9 LOF genotype on endothelial dysfunction. Methods: Secondary analyses of a prospective observational cohort of pediatric septic shock. Genetic variants of PCSK9 and LDLR genes, serum PCSK9, and lipoprotein concentrations were determined previously. Endothelial dysfunction markers were measured in day 1 serum. We conducted multivariable linear regression to test the influence of PCSK9 LOF genotype on endothelial markers, adjusted for age, complicated course, and low- and high-density lipoproteins (LDL and HDL). Causal mediation analyses to test impact of select endothelial markers on the association between PCSK9 LOF genotype and mortality. Juvenile Pcsk9 null and wildtype mice were subject to cecal slurry sepsis and endothelial markers were quantified. Results: A total of 474 patients were included. PCSK9 LOF was associated with several markers of endothelial dysfunction, with strengthening of associations after exclusion of those homozygous for the rs688 LDLR variant that renders it insensitive to PCSK9. Serum PCSK9 was not correlated with endothelial dysfunction. PCSK9 LOF influenced concentrations of Angiopoietin-1 (Angpt-1) upon adjusting for potential confounders including lipoprotein concentrations, with false discovery adjusted p value of 0.042 and 0.013 for models that included LDL and HDL, respectively. Causal mediation analysis demonstrated that the effect of PCSK9 LOF on mortality was mediated by Angpt-1 (p = 0.0008). Murine data corroborated these results with lower Angpt-1 and higher soluble thrombomodulin among knockout mice with sepsis relative to the wildtype. Conclusions: We present genetic and biomarker association data that suggest a potential direct role of the PCSK9-LDLR pathway on Angpt-1 in the developing host with septic shock and warrant external validation. Further, mechanistic studies on the role of PCSK9-LDLR pathway on vascular homeostasis may lead to the development of pediatric-specific sepsis therapies.Item Disruption of Kidney–Immune System Crosstalk in Sepsis with Acute Kidney Injury: Lessons Learned from Animal Models and Their Application to Human Health(MDPI, 2022-02-01) LaFavers, Kaice; Medicine, School of MedicineIn addition to being a leading cause of morbidity and mortality worldwide, sepsis is also the most common cause of acute kidney injury (AKI). When sepsis leads to the development of AKI, mortality increases dramatically. Since the cardinal feature of sepsis is a dysregulated host response to infection, a disruption of kidney–immune crosstalk is likely to be contributing to worsening prognosis in sepsis with acute kidney injury. Since immune-mediated injury to the kidney could disrupt its protein manufacturing capacity, an investigation of molecules mediating this crosstalk not only helps us understand the sepsis immune response, but also suggests that their supplementation could have a therapeutic effect. Erythropoietin, vitamin D and uromodulin are known to mediate kidney–immune crosstalk and their disrupted production could impact morbidity and mortality in sepsis with acute kidney injury.