Racial differences in vasopressor requirements for septic shock

Racial Disparities in Plasma Cytokine and Microbiome Profiles

BACKGROUND

Many health issues prevalent in African American (AA) populations are associated with chronic inflammation and related health conditions, including autoimmune diseases, infectious diseases, neurologic disorders, metabolic syndromes, and others. The current study aims to understand plasma microbiome translocation as a potential trigger for chronic inflammation.

METHODS

In this study, 16 Caucasian American (CA) and 22 African American (AA) healthy individuals were recruited. Microbial DNA was isolated from the plasma samples and sequenced via microbial 16S rRNA V3-4 sequencing. The plasma levels of 33 cytokines and chemokines were evaluated. The proinflammatory microbiomes were verified using human THP-1 cells in vitro.

RESULTS

The plasma levels of IL-6, IL-15, MIP-1α, MIP-1β, and MIP-3α were higher in the AA people, whereas IL-1α and IL-27 were elevated in the CA people. The plasma microbiomes exhibited eight bacterial genera/phyla differentially enriched in the CA and AA people. Given the critical role of IL-6 in chronic inflammation and associated diseases, we identified five bacteria genera significantly associated with IL-6. The abundance of Actinomyces was positively correlated with the plasma IL-6 level (r = 0.41, p = 0.01), while the abundance of Kurthia (r = -0.34, p = 0.04), Noviherbaspirillum (r = -0.34, p = 0.04), Candidatus Protochlamydia (r = -0.36, p = 0.03), and Reyranella (r = -0.39, p = 0.02) was negatively correlated with this. Finally, the THP-1 cells treated with heat-killed bacteria produced higher levels of IL-6 in vitro in response to the Actinomyces species compared to the species in the genus either uncorrelated or negatively correlated with IL-6.

CONCLUSIONS

This is the first study to report potential blood microbiome translocation as a driver for persistently elevated IL-6 levels in the periphery in healthy AA versus CA people. Understanding the plasma microbiome linked to the IL-6 levels in people with different racial backgrounds is essential to unraveling the therapeutic approaches to improve precision medicine.

Linking Sepsis with chronic arterial hypertension, diabetes mellitus, and socioeconomic factors in the United States: A scoping review

RATIONALE

Sepsis is a syndrome of life-threatening organ dysfunction caused by a dysregulated host immune response to infection. Social risk factors including location and poverty are associated with sepsis-related disparities. Understanding the social and biological phenotypes linked with the incidence of sepsis is warranted to identify the most at-risk populations. We aim to examine how factors in disadvantage influence health disparities related to sepsis.

METHODS

A scoping review was performed for English-language articles published in the United States from 1990 to 2022 on PubMed, Web of Science, and Scopus. Of the 2064 articles found, 139 met eligibility criteria and were included for review.

RESULTS

There is consistency across the literature of disproportionately higher rates of sepsis incidence, mortality, readmissions, and associated complications, in neighborhoods with socioeconomic disadvantage and significant poverty. Chronic arterial hypertension and diabetes mellitus also occur more frequently in the same geographic distribution as sepsis, suggesting a potential shared pathophysiology.

CONCLUSIONS

The distribution of chronic arterial hypertension, diabetes mellitus, social risk factors associated with socioeconomic disadvantage, and sepsis incidence, are clustered in specific geographical areas and linked by endothelial dysfunction. Such population factors can be utilized to create equitable interventions aimed at mitigating sepsis incidence and sepsis-related disparities.

Perioperative Vasopressors are Associated with Delayed Graft Function in Kidney Transplant Recipients in a Primarily Black and Hispanic Cohort

Introduction: Negative outcome studies of vasopressors in kidney transplant have not focused on patient populations that are predominantly Black or Hispanic. Project Aims: The evaluation sought to investigate the independent impact of perioperative vasopressors on postoperative renal allograft function in a sample drawn from a primarily Black and Hispanic population. Design: Retrospective, observational, single-center evaluation of patients > 18 years old who underwent kidney transplantation comparing outcomes based on vasopressor exposure. Results: The study included 150 patients of which 60 received vasopressors. The primary outcome differed between groups with delayed graft function occurring in 17(28%) versus 11(12.2%) occurring more often in those that received perioperative vasopressors (P = 0.02). The serum creatinine at postoperative day 7 was higher (2.69 vs1.52 mg/dL, P = 0.004), postoperative day 7 eGFR was worse (27.3 vs 52.9 mL/min/1.73m2, P = 0.002) in patients who received vasopressors. Patients who received perioperative vasopressors experienced more postoperative arrhythmias (15% vs 8%, P = 0.007), insulin infusion therapy (26.7% vs 13.3%, P = 0.04), and increased hospital length of stay (6 days vs 5 days, P = 0.006). Using IPWRA, patients receiving vasopressors were more likely to experience delayed function, relative risk difference of 22% (95% CI:0.08-0.35;P = 0.002) and in multivariate logistic regression modeling, an increased odds ratio of 3.2 (95% CI:1.1-8.62;P = 0.022). Conclusions: The use of perioperative vasopressors was independently associated with worsened early renal allograft function including delayed graft function, increased adverse events such as postoperative arrhythmias, and longer ICU length of stay. Further investigation is needed surrounding vasopressor use in this population.

Physiology of Human Hemorrhage and Compensation

Hemorrhage is a leading cause of death following traumatic injuries in the United States. Much of the previous work in assessing the physiology and pathophysiology underlying blood loss has focused on descriptive measures of hemodynamic responses such as blood pressure, cardiac output, stroke volume, heart rate, and vascular resistance as indicators of changes in organ perfusion. More recent work has shifted the focus toward understanding mechanisms of compensation for reduced systemic delivery and cellular utilization of oxygen as a more comprehensive approach to understanding the complex physiologic changes that occur following and during blood loss. In this article, we begin with applying dimensional analysis for comparison of animal models, and progress to descriptions of various physiological consequences of hemorrhage. We then introduce the complementary side of compensation by detailing the complexity and integration of various compensatory mechanisms that are activated from the initiation of hemorrhage and serve to maintain adequate vital organ perfusion and hemodynamic stability in the scenario of reduced systemic delivery of oxygen until the onset of hemodynamic decompensation. New data are introduced that challenge legacy concepts related to mechanisms that underlie baroreflex functions and provide novel insights into the measurement of the integrated response of compensation to central hypovolemia known as the compensatory reserve. The impact of demographic and environmental factors on tolerance to hemorrhage is also reviewed. Finally, we describe how understanding the physiology of compensation can be translated to applications for early assessment of the clinical status and accurate triage of hypovolemic and hypotensive patients. © 2021 American Physiological Society. Compr Physiol 11:1531-1574, 2021.

[Reality and prospects of sepsis epidemiology research]

Current foreign and Russian literature for sepsis epidemiology is reviewed. There is advanced incidence of sepsis in developing countries among young people as a rule. Absent high-quality epidemiological studies lead to overdiagnosis of sepsis and increased morbidity. National and territorial screening and diagnostic programs for sepsis became possible with introduction of new recommendations 'Sepsis-3'. Thus, there is a possibility to systematize regular epidemiological studies devoted to sepsis.

Blood pressure targets for vasopressor therapy: a systematic review

Physicians often prescribe vasopressors to correct pathological vasodilation and improve tissue perfusion in patients with septic shock, but the evidence to inform practice on vasopressor dosing is weak. We undertook a systematic review of clinical studies evaluating different blood pressure targets for the dosing of vasopressors in septic shock. We searched MEDLINE, EMBASE, CENTRAL (to November 2013), reference lists from included articles, and trial registries for randomized controlled trials (RCTs) and observational and crossover intervention studies comparing different blood pressure targets for vasopressor therapy in septic shock. Two reviewers independently selected eligible studies and extracted data on standardized forms. We identified 2 RCTs and 10 crossover trials but no observational studies meeting our criteria. Only one RCT measured clinical outcomes after comparing mean arterial pressure targets of 80 to 85 mmHg versus 65 to 70 mmHg. There was no effect on 28-day mortality, but confidence intervals were wide (hazard ratio, 95% confidence interval [95% CI] 0.84 - 1.38). In contrast, this intervention was associated with a greater risk of atrial fibrillation (relative risk, 2.36; 95% CI, 1.18 - 4.72) and a lower risk of renal replacement therapy in hypertensive patients (relative risk, 0.75; 95% CI, 0.57 - 1.0). Crossover trials suggest that achieving higher blood pressure targets by increasing vasopressor doses increases heart rate and cardiac index with no effect on serum lactate. Our findings underscore the paucity of clinical evidence to guide the administration of vasopressors in critically ill patients with septic shock. Further rigorous research is needed to establish an evidence base for vasopressor administration in this population.

Modification of the β-Adrenoceptor Stimulation Pathway in Zucker Obese and Obese Diabetic Rat Myocardium

OBJECTIVES

Although metabolic syndrome is associated with increased sympathetic activity that chronically stimulates β-adrenoceptors, the β-adrenoceptor signaling pathway has been poorly studied in this situation. We studied the β-adrenoceptor signaling pathway in Zucker lean, obese, and obese diabetic rats.

DESIGN

Experimental, prospective study.

SETTING

University medical research laboratory.

SUBJECTS

Adult male Zucker lean (control), obese, and obese diabetic rats.

INTERVENTIONS

The effects of β-adrenoceptor stimulation were investigated in vitro in isolated left ventricular papillary muscles in control, obese, and obese diabetic rats. β1-, β2-, and β3-adrenoceptors and multidrug resistance-associated protein 4 were quantified by Western Blotting. Triglyceride, cholesterol, leptin, adiponectin, and C-peptide plasma concentrations were measured. Data are mean ± SD.

MEASUREMENTS AND MAIN RESULTS

Hyperlipidemia, high leptin, and C-peptide concentrations were observed in obese and obese diabetic strains, whereas hyperglycemia occurred only in the diabetic strain. The positive inotropic effect of isoproterenol was slightly reduced in obese rats (183% ± 11% of baseline; p = 0.003; n = 7) and markedly reduced in obese diabetic rats (137% ± 18% of baseline; p < 0.001; n = 10) when compared with control rats (210% ± 17% of baseline; n = 9). β1-adrenoceptors were down-regulated in obese (-41%; p = 0.02) and diabetic (-54%; p = 0.003) when compared with control rats, whereas β3-adrenoceptors and multidrug resistance-associated protein expression remained unchanged. Direct stimulation of adenylate cyclase with forskolin or administration of 3',5'-cyclic adenosine monophosphate suggests that subtle impairments also occurred beside the down-regulation of β1-adrenoceptor.

CONCLUSIONS

The positive inotropic effect of β-adrenoceptor stimulation is slightly decreased in Zucker obese rats and was more markedly decreased in Zucker diabetic rats. These decreases are mainly related to β1-adrenoceptor down-regulation.

Complicating Symmetric Peripheral Gangrene after Dopamine Therapy to Patients with Septic Shock

Dopamine is commonly used as a first-line agent in the treatment of patients with septic shock. The use of dopamine rarely causes symmetric peripheral dry gangrene. If the symmetric peripheral dry gangrene occurs in the patient after dopamine injection, it easily leads to disagreement between doctors and patients. A 60-year-old woman who had sudden septic shock was sent to intensive care unit (ICU). She was received dopamine injection according to the routine during treatment. Over the next 3 months, her limbs developed to dry gangrene and required amputation. The result shows that the occurrence of dry gangrene could only be associated with the long-term excessive use of dopamine according to the medical records. Although dopamine is a conventional drug for the treatment of septic shock, the forensic workers and clinicians must realize that vasopressors such as dopamine have been implicated directly or as a contributory cause in dry gangrene cases.