Biological and hemodynamic effects of low doses of fludrocortisone and hydrocortisone, alone or in combination, in healthy volunteers with hypoaldosteronism

Cardiac and vascular effects of low-dose steroids during the early phase of septic shock: An echocardiographic study

Background

Low-dose steroids are known to increase arterial pressure during septic shock through restoration of vasopressor response to norepinephrine. However, their effects on cardiac performance and ventriculo-arterial coupling (VAC) have never been scrutinized during human septic shock. The aim of this study was to perform a comprehensive description of the cardiovascular effects of low-dose steroids using modern echocardiographic tools (including speckle tracking imaging).

Methods

This prospective study was conducted in the intensive care unit (ICU) of a university hospital in France. Consecutive adult patients admitted for septic shock and requiring low-dose steroid therapy were prospectively enrolled within 24 h of septic shock onset. We recorded hemodynamic and echocardiographic data to explore left ventricle (LV) contractility, loading conditions and VAC just before the initiation of low-dose steroids (50 mg intravenous hydrocortisone plus 50 μg enteral fludrocortisone) and 2–4 h after.

Results

Fifty patients [65 (55–73) years; 33 men] were enrolled. Arterial pressure, heart rate, almost all LV afterload parameters, and most cardiac contractility parameters significantly improved after steroids. VAC improved with steroid therapy and less patients had uncoupled VAC (> 1.36) after (24%) than before (44%) treatment.

Conclusion

In this comprehensive echocardiographic study, we confirmed an improvement of LV afterload after initiation of low-dose steroids. We also observed an increase in LV contractility with improved cardiovascular efficiency (less uncoupling with decreased VAC).

Urinary steroidomic profiles by LC-MS/MS to monitor classic 21-Hydroxylase deficiency

21-hydroxylase deficiency, the most common enzyme defect associated with congenital adrenal hyperplasia (CAH) is characterized by an impairment of both aldosterone and cortisol biosynthesis. Close clinical and biological monitoring of Hydrocortisone (HC) and 9α-Fludrocortisone (FDR) replacement therapies is required to achieve an optimal treatment. As frequent and repeated reassessments of plasma steroids, 17-hydroxyprogesterone (17-OHP), androstenedione (Δ4-A) and testosterone (TESTO) is needed in childhood, urine steroid profiling could represent an interesting non-invasive alternative. We developed and validated a LC-MS/MS method for the measurement of 23-urinary mineralocorticoids, glucocorticoids and adrenal androgens. The usefulness of steroid profiling was investigated on single 08h00 am-collected spot urine for discriminating between 61 CAH patients and their age- and sex-matched controls. CAH patients were split into two groups according to their 08h00 am-plasma concentrations of 17-OHP: below (controlled patients, n = 26) and above 20 ng/mL (uncontrolled patients, n = 35). The lower limit of quantification and the wide analytical range allows to assay both free and total concentrations of the main urinary adreno-corticoids and their tetra-hydrometabolites. Extraction recoveries higher than 75% and intra-assay precision below 20% were found for most steroids. Urinary steroids upstream of the 21-hydroxylase defect were higher in uncontrolled CAH patients. Among CAH patients, plasma and urinary 17-OHP were closely correlated. As compared to controls, steroids downstream of the enzyme defect collapsed in CAH patients. This fall was more pronounced in controlled than in uncontrolled patients. Androgens (Δ4-A, TESTO and the sum etiocholanolone + androsterone) accumulated in uncontrolled CAH patients. A strong relationship was observed between plasma and urinary levels of androstenedione. Daily doses and urinary excretion of both FDR and HC were similar in both CAH groups. Urinary FDR was inversely related to the sodium-to-potassium ratio in urine. A partial least squares discriminant analysis model allowed to classify the patient's classes unaffected, controlled and un-controlled CAH patients based on urinary steroidomic profiles. Our LC-MS/MS method successfully established steroid profiling in urine and represents a useful and non-invasive tool for discriminating CAH patients according to treatment efficiency.

[Imaging and preoperative planning for osteotomies around the knee]

Physiologic alignment of the human lower leg is well defined. The etiology for malalignment comprises constitutional, degenerative and posttraumatic conditions. Osteotomies around the knee can correct the malalignment, provided that the origin of deviation is in proximity of the knee center. Crucial factors for the evaluation of axis deviation are the weight-bearing line, the mechanical axes of femur and tibia, the joint line angles and the center of the hip, knee and upper ankle joint. Careful preoperative planning is mandatory for reproducible clinical results. For the treatment of varus osteoarthritis of the knee, a slight overcorrection to the 62% width of the lateral tibial plateau is frequently advocated. In valgus knees, a correction of the postoperative weight-bearing line to physiologic conditions (44% of the lateral tibial width) is regarded to be sufficient. Recently, individualized planning of the correction angle is advocated to better address the underlying pathology of each patient.

Pharmacokinetics of oral fludrocortisone in septic shock

AIM

The combination of hydrocortisone and fludrocortisone improved outcomes in septic shock. However, the specific role of fludrocortisone remains controversial and its pharmacokinetics (PK) has never been investigated in septic shock. This study aimed at characterizing the PK of fludrocortisone in septic shock.

METHODS

This was a single-centre ancillary PK study of a large multinational trial of crystalloids versus colloids for acute hypovolemia in intensive care unit (ICU) patients. In 21 adults with septic shock, fludrocortisone plasma concentrations were measured by liquid chromatography-mass spectrometry tandem analysis, before and repeatedly until 18 h after an oral dose of 50 μg. PK parameters were estimated using a nonlinear mixed-effects modelling.

RESULTS

Undetectable plasma concentrations were observed in 7 out of 21 patients. In the remaining 14 patients, plasma fludrocortisone concentrations were best described by a one-compartmental model with first-order absorption, a lag time (T_lag ) before the absorption phase, and first-order elimination. Severity of illness, as quantified by Simplified Acute Physiology Score II, significantly increased T_lag and apparent clearance. There was a large inter-individual variability in PK parameters. The population estimates of PK parameters (inter-individual variability) were: T_lag 0.65 h (98%), apparent clearance 40 l h^-1 (49%) and apparent volume of distribution 78 l (75%). Plasma half-life was estimated at 1.35 h (95% CI, 0.84-2.03) and area under the curve of plasma concentrations was estimated at 1.25 μg h l^-1 (95% CI, 1.09-1.46).

CONCLUSIONS

A single oral dose of fludrocortisone yielded undetectable plasma concentrations in one-third of adults with septic shock. Fludrocortisone PK showed a short plasma elimination half-life and a large inter-individual variability.

Low doses of fludrocortisone and hydrocortisone, alone or in combination, on vascular responsiveness to phenylephrine in healthy volunteers

AIMS

A single administration of hydrocortisone has been shown to enhance the pressor response to phenylephrine in healthy volunteers and to norepinephrine in septic shock patients. Similar data do not exist for fludrocortisone. Since there continues to be disagreement about the utility of fludrocortisone in septic shock, we assessed the effects of a single administration of low doses of hydrocortisone (50 mg intravenously) and fludrocortisone (50 μg orally), given either alone or in combination, on phenylephrine mean arterial pressure and cardiac systolic and diastolic function dose-response relationships in 12 healthy male volunteers with hypo-aldosteronism induced by intravenous sodium loading.

METHODS

This was a placebo-controlled, randomized, double-blind, crossover study performed according to a 2 × 2 factorial design. Subjects received first a 2000 ml infusion of NaCl 0.9% during 2 h. Then fludrocortisone 50 μg (or its placebo) was administered orally and hydrocortisone 50 mg (or its placebo) was injected intravenously. At 1.5 h after treatment administration, incremental doses of phenylephrine were infused (from 0.01 to 3 μg kg(-1) min(-1)), each dose being infused during 5 min.

RESULTS

Both fludrocortisone (P < 0.001) and hydrocortisone (P = 0.002) induced a significant decrease in pressor response to phenylephrine, their effects being additive (fludrocortisone × hydrocortisone interaction, P = 0.792). The two drugs did not induce any detectable cardiac effect.

CONCLUSIONS

Single administrations of fludrocortisone and hydrocortisone decreased the pressor response to phenylephrine in healthy volunteers with hypo-aldosteronism. These similar effects of hydrocortisone and fludrocortisone probably express a rapid non-genomic vasodilating effect of the two steroids in the context of acute volume loading.

Gluco- and mineralocorticoid biological effects of a 7-day treatment with low doses of hydrocortisone and fludrocortisone in septic shock

PURPOSE

The benefits of low-dose steroids in septic shock remain controversial. We investigated if these low doses were able to induce their expected hormonal effects by analyzing the biological modifications observed during the study, which first demonstrated the survival benefit of low-dose steroids.

METHODS

This was a multicenter, placebo-controlled, randomized, double-blind study in which 299 septic shock patients received a 7-day treatment with a combination of hydrocortisone (50 mg intravenously four times daily) and fludrocortisone (50 μg orally once daily) or matching placebos. Gluco- and mineralocorticoid biological effects observed during the 7 days of treatment were compared between groups.

RESULTS

Steroids significantly decreased eosinophil counts from day 2 to day 7. Steroids significantly increased plasma glucose from day 2 (compared with placebos: +0.8 mmol/l) to day 7 (+1.8 mmol/l) and cholesterol from day 3 (+0.54 mmol/l) to day 7 (+0.39 mmol/l). Steroids significantly increased plasma sodium from day 3 (+2 mmol/l) to day 7 (+5 mmol/l) and significantly decreased plasma potassium on day 7 (-0.2 mmol/l). Steroids significantly decreased urinary sodium/potassium ratio from day 2 (-47 %) to day 7 (-57 %) and sodium fractional excretion from day 3 (-25 %) to day 7 (-66 %). Steroids significantly increased urine output on day 4 and 5 and osmolar clearance from day 4 to day 7, and decreased free-water clearance from day 4 to day 7, this effect being significant on day 4 and 6.

CONCLUSIONS

In septic shock, low-dose steroids induced both gluco- and mineralocorticoid biological effects and seemed to improve renal function. Most of these effects appeared after 2-3 days of treatment and lasted at least until the end of treatment.