Mineralocorticoid effects due to cortisol inactivation overload explain the beneficial use of hydrocortisone in septic shock

The Mineralocorticoid Receptor in the Vasculature: Friend or Foe?

Originally described as the renal aldosterone receptor that regulates sodium homeostasis, it is now clear that mineralocorticoid receptors (MRs) are widely expressed, including in vascular endothelial and smooth muscle cells. Ample data demonstrate that endothelial and smooth muscle cell MRs contribute to cardiovascular disease in response to risk factors (aging, obesity, hypertension, atherosclerosis) by inducing vasoconstriction, vascular remodeling, inflammation, and oxidative stress. Extrapolating from its role in disease, evidence supports beneficial roles of vascular MRs in the context of hypotension by promoting inflammation, wound healing, and vasoconstriction to enhance survival from bleeding or sepsis. Advances in understanding how vascular MRs become activated are also reviewed, describing transcriptional, ligand-dependent, and ligand-independent mechanisms. By synthesizing evidence describing how vascular MRs convert cardiovascular risk factors into disease (the vascular MR as a foe), we postulate that the teleological role of the MR is to coordinate responses to hypotension (the MR as a friend).

Combination of low-dose glucocorticosteroids and mineralocorticoids as adjunct therapy for adult patients with septic shock: A systematic review and meta-analysis of randomized trials and observational studies

Background:

The role of the combination of glucocorticosteroids and mineralocorticosteroids in treating septic shock is not well-defined. The aim of this study was to perform a systematic review and meta-analysis of the randomized controlled trials and observational studies assessing the effect of low-dose hydrocortisone and fludrocortisone on patients with septic shock.

Materials and Methods:

MEDLINE, Scopus, and Cochrane databases were reviewed. A random effect model meta-analysis was used and I-square was used to assess the heterogeneity. Short-term mortality was chosen as our primary end point. A subgroup analysis was performed including only the randomized controlled trials.

Results:

A total of 10,550 patients were included in this meta-analysis. Administration of the steroid combination was associated with improved short-term mortality (odds ratio, 0.78, confidence interval, 0.64–0.96), intensive care unit mortality, and shock reversal, without increase in steroid-related side effects, such as secondary infection or gastrointestinal hemorrhage.

Conclusion:

This systematic review and meta-analysis showed that use of the combination of glucocorticosteroids and mineralocorticosteroids has a beneficial impact on short-term mortality, intensive care unit mortality, and shock reversal, without increasing the incidence of gastrointestinal hemorrhage or superinfection in patients with septic shock, when used as an adjunct treatment to the established standard of care.

Effect of adjunctive corticosteroids on clinical outcomes in adult patients with septic shock - a meta-analysis of randomized controlled trials and trial sequential analysis

PURPOSE

To assess the effect of corticosteroids on clinical outcomes in patients with septic shock.

MATERIALS AND METHODS

We searched databases for eligible randomized controlled trials (RCTs) published prior to March 12, 2018. The relative risk (RR), mean difference (MD) and 95% confidence intervals (CI) were determined. Trial sequential analysis (TSA) were performed.

RESULTS

Seventeen RCTs were identified. Overall, corticosteroid therapy was not associated with a lower short-term mortality compared with placebo. Sub-analysis of trials with a low risk of bias demonstrated a beneficial effect of corticosteroids in reducing short-term mortality. Sub-analysis revealed that a daily dose of 200 mg hydrocortisone provided no benefit in reducing short-term mortality (random-effects RR = 0.98, 95% CI: 0.90-1.06, P = 0.555; TSA-adjusted CI: 0.88-1.09; I² = 0%), and the boundary for futility was crossed. However, a significant reduction in short-term mortality was found in a subgroup of trials that received dual corticosteroids (random-effects RR = 0.88; 95% CI: 0.79-0.97, P = 0.013; I² = 0%), but this benefit disappeared after adjustment with TSA (TSA-adjusted CI: 0.76-1.02).

CONCLUSIONS

Future trials are unlikely to detect a reduction in short-term mortality at a daily doses of 200 mg hydrocortisone. More evidence is required to confirm the beneficial effects of dual corticosteroid therapy.

Immune Effects of Corticosteroids in Sepsis

Sepsis, a life-threatening organ dysfunction, results from a dysregulated host response to invading pathogens that may be characterized by overwhelming systemic inflammation or some sort of immune paralysis. Sepsis remains a major cause of morbidity and mortality. Treatment is nonspecific and relies on source control and organ support. Septic shock, the most severe form of sepsis is associated with the highest rate of mortality. Two large multicentre trials, undertaken 15 years apart, found that the combination of hydrocortisone and fludrocortisone significantly reduces mortality in septic shock. The corticosteroids family is composed of several molecules that are usually characterized according to their glucocorticoid and mineralocorticoid power, relative to hydrocortisone. While the immune effects of glucocorticoids whether mediated or not by the intracellular glucocorticoid receptor have been investigated for several decades, it is only very recently that potential immune effects of mineralocorticoids via non-renal mineralocorticoid receptors have gained popularity. We reviewed the respective role of glucocorticoids and mineralocorticoids in counteracting sepsis-associated dysregulated immune systems.

Hypothalamic-pituitary-adrenal axis in lethal canine Staphylococcus aureus pneumonia

The clinical significance and even existence of critical illness-related corticosteroid insufficiency is controversial. Here, hypothalamic-pituitary-adrenal (HPA) function was characterized in severe canine Staphylococcus aureus pneumonia. Animals received antibiotics and titrated life-supportive measures. Treatment with dexamethasone, a glucocorticoid, but not desoxycorticosterone, a mineralocorticoid, improves outcome in this model. Total and free cortisol, adrenocorticotropic hormone (ACTH). and aldosterone levels, as well as responses to exogenous ACTH were measured serially. At 10 h after the onset of infection, the acute HPA axis stress response, as measured by cortisol levels, exceeded that seen with high-dose ACTH stimulation but was not predictive of outcome. In contrast to cortisol, aldosterone was largely autonomous from HPA axis control, elevated longer, and more closely associated with survival in early septic shock. Importantly, dexamethasone suppressed cortisol and ACTH levels and restored ACTH responsiveness in survivors. Differing strikingly, nonsurvivors, sepsis-induced hypercortisolemia, and high ACTH levels as well as ACTH hyporesponsiveness were not influenced by dexamethasone. During septic shock, only serial measurements and provocative testing over a well-defined timeline were able to demonstrate a strong relationship between HPA axis function and prognosis. HPA axis unresponsiveness and high aldosterone levels identify a septic shock subpopulation with poor outcomes that may have the greatest potential to benefit from new therapies.

Adrenal insufficiency and response to corticosteroids in hypotensive critically ill children with cancer

BACKGROUND

Assessment and treatment of adrenal axis function in critically ill pediatric patients with oncologic disorders have not been well elucidated. Critically ill children with oncologic disorders may be at increased risk for adrenal insufficiency (AI).

OBJECTIVE

The aim of the present study was to evaluate the incidence of AI in a cohort of hypotensive patients with oncologic disorders and the correlation of AI with hemodynamic response to corticosteroids.

DESIGN/METHODS

This is a retrospective review of pediatric oncology patients with systemic inflammatory response syndrome and vasopressor-dependent shock receiving protocol-based adrenocorticotropin testing and steroid supplementation. Vasopressor dose requirements were evaluated before and after the initiation of corticosteroids. Absolute AI (AAI) was defined as baseline cortisol less than 18 μg/dL. Relative AI (RAI) was defined as δ-cortisol less than 9 μg/dL.

RESULTS

Twenty patients received adrenocorticotropin testing; primary diagnoses were 13 hematologic malignancies and 7 solid tumors. The median age was 132 months (range, 4-224 months). The median fluid resuscitation was 80 mL/kg (range, 60-120 mL/kg), with 10 (50%) of 20 patients requiring mechanical ventilation for a median of 12 days. Overall, 10 (50%) of 20 patients met the definition for RAI, 15 (75%) of 20 met the definition for AAI, and 18 (90%) of 20 had either AAI or RAI. All patients received steroids: 18 (90%) of 20 on dopamine and 17 (85%) of 20 on norepinephrine. After the introduction of steroids, dosage of norepinephrine and dopamine was significantly reduced in 4 hours (P = .0001).

CONCLUSIONS

Both RAI and AAI were common in this cohort of critically ill pediatric patients with oncologic disorders. Introduction of steroids was associated with a significant reduction in vasopressors dose.

Mineralocorticoid deficiency in hemorrhagic shock

BACKGROUND

In the critically ill, mineralocorticoid deficiency (MD) is associated with greater disease severity, the development of acute renal insufficiency, and increased mortality. We hypothesized that severely injured trauma patients presenting with hemorrhagic shock would demonstrate a high degree of MD. We also hypothesized that MD in these patients would be associated with increased length of stay, hypotension, fluid requirements, and acute kidney injury (AKI).

MATERIALS AND METHODS

Thirty-two trauma patients in hemorrhagic shock on admission to the trauma bay (SBP <90 mm Hg × 2) were enrolled. Blood samples were obtained on ICU admission and 8, 16, 24, and 48 hours later. Plasma aldosterone (PA) and renin (PR) were assayed by radioimmunoassay. MD was defined as a ratio of PA/PR ≤2. Demographic data, injury severity score, ICU and hospital length of stay, fluid requirements, mean arterial pressure, serum sodium, hypotension, and risk for AKI were compared for patients with and without MD.

RESULTS

At ICU admission, 48% of patients met criteria for MD. Patients with MD were significantly more likely to experience hypotension (MAP ≤60 mm Hg) during the study period. MD patients required significantly more units of blood in 48 h than non-MD patients (13 [7-22] versus 5 [2-7], P = 0.015) and had increased crystalloid requirements (18L [14-23] versus 9L [6-10], P < 0.001). MD patients were at higher risk for AKI according to RIFLE and AKIN criteria.

CONCLUSIONS

MD is a common entity in trauma patients presenting in hemorrhagic shock. Patients with MD required a more aggressive resuscitative effort, were more likely to experience hypotension, and had a higher risk of AKI than non-MD patients. Future studies are needed to fully understand the impact of MD following trauma and the potential role for hormonal replacement therapy.

Efficacy of selective mineralocorticoid and glucocorticoid agonists in canine septic shock

OBJECTIVE

Corticosteroid regimens that stimulate both mineralocorticoid and glucocorticoid pathways consistently reverse vasopressor-dependent hypotension in septic shock but have variable effects on survival. The objective of this study was to determine whether exogenous mineralocorticoid and glucocorticoid treatments have distinct effects and whether the timing of administration alters their effects in septic shock. DESIGN, SETTING, SUBJECTS, AND INTERVENTIONS: Desoxycorticosterone, a selective mineralocorticoid agonist; dexamethasone, a selective glucocorticoid agonist; and placebo were administered either several days before (prophylactic) or immediately after (therapeutic) infectious challenge and continued for 96 hrs in 74 canines with staphylococcal pneumonia.

MEASUREMENTS AND MAIN RESULTS

Effects of desoxycorticosterone and dexamethasone were different and opposite depending on timing of administration for survival (p = .05); fluid requirements (p = .05); central venous pressures (p ≤ .007); indicators of hemoconcentration (i.e., sodium [p = .0004], albumin [p = .05], and platelet counts [p = .02]); interleukin-6 levels (p = .04); and cardiac dysfunction (p = .05). Prophylactic desoxycorticosterone treatment significantly improved survival, shock, and all the other outcomes stated, but therapeutic desoxycorticosterone did not. Conversely, prophylactic dexamethasone was much less effective for improving these outcomes compared with therapeutic dexamethasone with the exception of shock reversal. Prophylactic dexamethasone given before sepsis induction also significantly reduced serum aldosterone and cortisol levels and increased body temperature and lactate levels compared with therapeutic dexamethasone (p ≤ .05), consistent with adrenal suppression.

CONCLUSIONS

In septic shock, mineralocorticoids are only beneficial if given prophylactically, whereas glucocorticoids are most beneficial when given close to the onset of infection. Prophylactic mineralocorticoids should be further investigated in patients at high risk to develop sepsis, whereas glucocorticoids should only be administered therapeutically to prevent adrenal suppression and worse outcomes.

Incidence of adrenal insufficiency and impact of corticosteroid supplementation in critically ill children with systemic inflammatory syndrome and vasopressor-dependent shock

INTRODUCTION

Adrenal insufficiency may be common in adults and children with vasopressor-resistant shock. We developed a protocolized approach to low-dose adrenocorticotropin testing and empirical low-dose glucocorticoid/mineralocorticoid supplementation in children with systemic inflammatory response syndrome and persistent hypotension following fluid resuscitation and vasopressor infusion.

HYPOTHESIS

We hypothesized that absolute and relative adrenal insufficiency was common in children with systemic inflammatory response syndrome requiring vasopressor support and that steroid administration would be associated with decreased vasopressor need.

METHODS

Retrospective review of pediatric patients with systemic inflammatory response syndrome and vasopressor-dependent shock receiving protocol-based adrenocorticotropin testing and low-dose steroid supplementation. The incidence of absolute and relative adrenal insufficiency was determined using several definitions. Vasopressor dose requirements were evaluated before, and following, initiation of corticosteroids.

RESULTS

Seventy-eight patients met inclusion criteria for systemic inflammatory response syndrome and shock; 40 had septic shock. Median age was 84 months (range, 0.5-295). By adrenocorticotropin testing, 44 (56%) had absolute adrenal insufficiency, 39 (50%) had relative adrenal insufficiency, and 69 (88%) had either form of adrenal insufficiency. Adrenal insufficiency incidence was significantly higher in children >2 yrs (p = .0209). Therapeutic interventions included median 80-mL/kg fluid resuscitation; 65% of patients required dopamine, 58% norepinephrine, and 49% dopamine plus norepinephrine. With steroid supplementation, median dopamine dose decreased from 10 to 4 μg/kg/min at 4 hrs (p = .0001), and median dose of norepinephrine decreased from 0.175 μg/kg/min to 0.05 μg/kg/min at 4 hrs (p = .039).

CONCLUSIONS

Absolute and relative adrenal insufficiency was prevalent in this cohort of children with systemic inflammatory response syndrome and vasopressor-dependent shock and increased with age. Introduction of steroids produced a significant reduction in vasopressor duration and dosage. Use of low-dose adrenocorticotropin testing may help further delineate populations who require steroid supplementation.