Rapid permissive action of dexamethasone on the regulation of blood pressure in a rat model of septic shock

Vasopressin and methylprednisolone and hemodynamics after in-hospital cardiac arrest - A post hoc analysis of the VAM-IHCA trial

INTRODUCTION

The Vasopressin and Methylprednisolone for In-Hospital Cardiac Arrest (VAM-IHCA) trial demonstrated a significant improvement in return of spontaneous circulation (ROSC) with no clear effect on long-term outcomes. The objective of the current manuscript was to evaluate the hemodynamic effects of intra-cardiac arrest vasopressin and methylprednisolone during the first 24 hours after ROSC.

METHODS

The VAM-IHCA trial randomized patients with in-hospital cardiac arrest to a combination of vasopressin and methylprednisolone or placebo during the cardiac arrest. This study is a post hoc analysis focused on the hemodynamic effects of the intervention after ROSC. Post-ROSC data on the administration of glucocorticoids, mean arterial blood pressure, heart rate, blood gases, vasopressor and inotropic therapy, and sedation were collected. Total vasopressor dose between the two groups was calculated based on noradrenaline-equivalent doses for adrenaline, phenylephrine, terlipressin, and vasopressin.

RESULTS

The present study included all 186 patients who achieved ROSC in the VAM IHCA-trial of which 100 patients received vasopressin and methylprednisolone and 86 received placebo. The number of patients receiving glucocorticoids during the first 24 hours was 22/86 (26%) in the placebo group and 14/100 (14%) in the methylprednisolone group with no difference in the cumulative hydrocortisone-equivalent dose. There was no significant difference between the groups in the mean cumulative noradrenaline-equivalent dose (vasopressin and methylprednisolone: 603 ug/kg [95CI% 227; 979] vs. placebo: 651 ug/kg [95CI% 296; 1007], mean difference -48 ug/kg [95CI% -140; 42.9], p = 0.30), mean arterial blood pressure, or lactate levels. There was no difference between groups in arterial blood gas values and vital signs.

CONCLUSION

Treatment with vasopressin and methylprednisolone during cardiac arrest caused no difference in mean arterial blood pressure, vasopressor use, or arterial blood gases within the first 24 hours after ROSC when compared to placebo.

Estrogen ameliorates sepsis-induced vascular hyporeactivity in thoracic aorta of female rats via permissive effect of GRα expression

OBJECTIVE

Estrogen is correlated to the lower mortality and disease severity of female than that of male, which indicates the potential therapeutic role of estrogen supplement therapy in sepsis. The structure of Daidzein is similar to that of 17β estradiol (E₂), an estrogen in human body, causing the exogenous Daidzein can interact with estrogen receptor as well as E₂ in the body. We aim to explore the therapeutic role of estrogen in sepsis-induced vascular dysfunction. Also, we wonder if estrogen regulates blood pressure via glucocorticoid-mediated vascular reactivity.

METHODS

Female SD rats received ovariectomy (OVX) to induce estrogen deficiency. After 12 weeks of administration, cecal ligation and puncture (CLP) was used to establish the in vivo model of sepsis. Lipopolysaccharide (LPS) was used to construct the in vitro model of sepsis in vascular smooth muscle cells (VSMCs). E₂ and Daidzein were used for estrogen supplement therapy.

RESULTS

E₂ and Daidzein significantly inhibited inflammation infiltration and histopathological injury in thoracic aorta in the rat model with CLP. E₂ and Daidzein improved carotid pressure and vascular hyporeactivity in sepsis rats with OVX. Importantly, E₂ and Daidzein promoted glucocorticoid permissive action and increased glucocorticoid receptor α (GRα) expression in thoracic aorta smooth muscle cells. E₂ and Daidzein upregulated GRα, and inhibits cytokine production, proliferative phenotype and cell migration in LPS-induced VSMCs.

CONCLUSION

Estrogen improved vascular hyporeactivity in thoracic aorta induced by sepsis via permissive effect of GRα expression.

Chronic restraint stress promotes the mobilization and recruitment of myeloid-derived suppressor cells through β-adrenergic-activated CXCL5-CXCR2-Erk signaling cascades

Myeloid-derived suppressor cells (MDSCs) play an important role in tumor immune escape. Recent studies have shown that MDSCs contribute to tumor progression under psychological stress, but the underlying mechanism of MDSCs mobilization and recruitment remains largely unknown. In the present study, a chronic restraint stress paradigm was applied to the H22 hepatocellular carcinoma (HCC) bearing mice to mimic the psychological stress. We observed that chronic restraint stress significantly promoted HCC growth, as well as the mobilization of MDSCs to spleen and tumor sites from bone marrow. Meanwhile, chronic restraint stress enhanced the expression of C-X-C motif chemokine receptor 2 (CXCR2) and pErk1/2 in bone marrow MDSCs, together with elevated chemokine (C-X-C motif) ligand 5 (CXCL5) expression in tumor tissues. In vitro, the treatments of MDSCs with epinephrine (EPI) and norepinephrine (NE) but not corticosterone (CORT)-treated H22 conditioned medium obviously inhibited T-cell proliferation, as well as enhanced CXCR2 expression and extracellular signal-regulated kinase (Erk) phosphorylation. In vivo, β-adrenergic blockade with propranolol almost completely reversed the accelerated tumor growth induced by chronic restraint stress and inactivated CXCL5-CXCR2-Erk signaling pathway. Our findings support the crucial role of β-adrenergic signaling cascade in the mobilization and recruitment of MDSCs under chronic restraint stress.

Vasopressin and methylprednisolone for in-hospital cardiac arrest - Protocol for a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To describe the clinical trial "Vasopressin and Methylprednisolone for In-Hospital Cardiac Arrest" (VAM-IHCA).

METHODS

The VAM-IHCA trial is an investigator-initiated, multicenter, randomized, placebo-controlled, parallel group, double-blind, superiority trial of vasopressin and methylprednisolone during adult in-hospital cardiac arrest. The study drugs consist of 40 mg methylprednisolone and 20 IU of vasopressin given as soon as possible after the first dose of adrenaline. Additional doses of vasopressin (20 IU) will be administered after each adrenaline dose for a maximum of four doses (80 IU).The primary outcome is return of spontaneous circulation and key secondary outcomes include survival and survival with a favorable neurological outcome at 30 days. 492 patients will be enrolled. The trial was registered at the EU Clinical Trials Register (EudraCT Number: 2017-004773-13) on Jan. 25, 2018 and ClinicalTrials.gov (Identifier: NCT03640949) on Aug. 21, 2018.

RESULTS

The trial started in October 2018 and the last patient is anticipated to be included in January 2021. The primary results will be reported after 3-months follow-up and are, therefore, anticipated in mid-2021.

CONCLUSION

The current article describes the design of the VAM-IHCA trial. The results from this trial will help clarify whether the combination of vasopressin and methylprednisolone when administered during in-hospital cardiac arrest improves outcomes.

Glucocorticoids in Sepsis: To Be or Not to Be

Sepsis is a highly lethal syndrome resulting from dysregulated immune and metabolic responses to infection, thereby compromising host homeostasis. Activation of the hypothalamic–pituitary–adrenal (HPA) axis and subsequently adrenocortical glucocorticoid (GC) production during sepsis are important regulatory processes to maintain homeostasis. Multiple preclinical studies have proven the pivotal role of endogenous GCs in tolerance against sepsis by counteracting several of the sepsis characteristics, such as excessive inflammation, vascular defects, and hypoglycemia. Sepsis is however often complicated by dysfunction of the HPA axis, resulting from critical-illness-related corticosteroid insufficiency (CIRCI) and GC resistance. Therefore, GCs have been tested as an adjunctive therapy in sepsis and septic shock in different randomized clinical trials (RCTs). Nonetheless, these studies produced conflicting results. Interestingly, adding vitamin C and thiamin to GC therapy enhances the effects of GCs, probably by reducing GC resistance, and this results in an impressive reduction in sepsis mortality as was shown in two recent preliminary retrospective before–after studies. Multiple RCTs are currently underway to validate this new combination therapy in sepsis.

Critical Roles of Endogenous Glucocorticoids for Disease Tolerance in Malaria

During malaria, the hypothalamic-pituitary-adrenal (HPA) axis is activated and glucocorticoid (GC) levels are increased, but their essential roles have been largely overlooked. GCs are decisive for systemic regulation of vital processes such as immune responses, vascular function, and metabolism, which are crucial in malaria. Here, we introduce GCs in general, followed by their versatile roles for disease tolerance in malaria. A complementary comparison is provided with their role in sepsis. Finally, potential translational implications are considered. The failed clinical trials of dexamethasone against cerebral malaria in the past have diminished the interest in GCs in malaria. However, the issue of relative corticosteroid insufficiency has barely been explored in malaria patients, but may hold promise for a better understanding and treatment of specific malaria complications.

Contributions of a survey and retrospective cohort study to the planning of a randomised controlled trial of corticosteroids in the treatment of paediatric septic shock

Background

Randomised controlled trials (RCTs) are challenging to conduct in a paediatric critical-care environment. Background work, including surveys and observational studies, is often used to determine disease estimates, sample sizes and design protocols when planning such RCTs. Our objective was to determine the necessity of performing a survey or a retrospective chart review or both when planning an RCT on corticosteroids in the treatment of paediatric septic shock.

Methods

We compared information on corticosteroid use for moderate to severe paediatric septic shock obtained from a survey of physician beliefs and stated practices with that obtained from a retrospective cohort study. The survey was conducted between February and March 2012 and the retrospective study included children from birth to 17 years of age admitted from January 2010 to June 2011. The survey and the retrospective study were conducted at four academic tertiary care centres in Canada.

Results

Survey responses from 23 physicians and retrospective data from 81 septic shock patients were included. The survey identified time to discontinuation of vasoactive infusions as the most feasible and clinically important outcome for an RCT on corticosteroids for paediatric septic shock. The retrospective chart review provided means and standard deviations for the suggested primary outcome, from which we could estimate sample sizes and justify the minimal clinically important difference. The survey found that physicians believe that patients with severe septic shock were most likely to benefit from corticosteroid administration but the majority stated they would be unwilling to randomise such patients, suggesting a lack of individual physician equipoise. The combined information from the survey and retrospective study suggested that enrolment of patients with moderate septic shock would be more feasible but that strategies would still have to be implemented to prevent open-label corticosteroid use.

Conclusions

The survey provided valuable information on the choice of primary outcome, target population and physician equipoise. The retrospective study provided estimates of patient numbers, the minimal clinically important difference, evidence for community equipoise and physician practice patterns. Strong consideration should be given to performing both types of studies prior to conducting RCTs in paediatric critical-care environments.

Adrenergic and glucocorticoid receptor antagonists reduce ozone-induced lung injury and inflammation

Recent studies showed that the circulating stress hormones, epinephrine and corticosterone/cortisol, are involved in mediating ozone-induced pulmonary effects through the activation of the sympathetic-adrenal-medullary (SAM) and hypothalamus-pituitary-adrenal (HPA) axes. Hence, we examined the role of adrenergic and glucocorticoid receptor inhibition in ozone-induced pulmonary injury and inflammation. Male 12-week old Wistar-Kyoto rats were pretreated daily for 7days with propranolol (PROP; a non-selective β adrenergic receptor [AR] antagonist, 10mg/kg, i.p.), mifepristone (MIFE; a glucocorticoid receptor [GR] antagonist, 30mg/kg, s.c.), both drugs (PROP+MIFE), or respective vehicles, and then exposed to air or ozone (0.8ppm), 4h/d for 1 or 2 consecutive days while continuing drug treatment. Ozone exposure alone led to increased peak expiratory flow rates and enhanced pause (Penh); with greater increases by day 2. Receptors blockade minimally affected ventilation in either air- or ozone-exposed rats. Ozone exposure alone was also associated with marked increases in pulmonary vascular leakage, macrophage activation, neutrophilic inflammation and lymphopenia. Notably, PROP, MIFE and PROP+MIFE pretreatments significantly reduced ozone-induced pulmonary vascular leakage; whereas PROP or PROP+MIFE reduced neutrophilic inflammation. PROP also reduced ozone-induced increases in bronchoalveolar lavage fluid (BALF) IL-6 and TNF-α proteins and/or lung Il6 and Tnfα mRNA. MIFE and PROP+MIFE pretreatments reduced ozone-induced increases in BALF N-acetyl glucosaminidase activity, and lymphopenia. We conclude that stress hormones released after ozone exposure modulate pulmonary injury and inflammatory effects through AR and GR in a receptor-specific manner. Individuals with pulmonary diseases receiving AR and GR-related therapy might experience changed sensitivity to air pollution.