Renal hemodynamics and water excretion in Addison's disease

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.

Excessive sensitivity to the hyponatremic effect of chlorpropamide in a patient with diabetes mellitus and anterior pituitary insufficiency

A 67-year-old diabetic woman with undiagnosed anterior pituitary insufficiency developed hyponatremic coma within 5 weeks after initiation of chlorpropamide therapy. A provocation test with 500 mg chlorpropamide orally led within five hours to hyponatremia and sopor with high urinary sodium excretion. This rapid development of the hyponatremic syndrome excludes water retention due to ADH as the dominant cause. It is more probable that known defects in renal sodium conservation, brought about by the anterior pituitary failure, have been potentiated by chlorpropamide.

Acute adrenal insufficiency in the burn intensive care unit

Acute adrenal insufficiency may underlie a confusing, stormy, intensive care unit course after a burn. The aetiology is most likely to be adrenal haemorrhage despite the absence of a coagulopathy. This report describes two patients who were diagnosed antemortem and successfully treated with replacement therapy. The aetiology, presentation, diagnosis and treatment of acute adrenal insufficiency in the intensive care unit is reviewed.

Nocturnal diuresis in panhypopituitarism

Although impaired water diuresis in adrenocortical insufficiency is well-known, little attention has been paid to the diuretic pattern at night. In two cases of panhypopituitarism, the nocturnal diuretic pattern was found to be quite different from that in the morning, and marked diuresis did occur after water loading at night, without any significant change of serum cortisol which remained at a low level throughout the day. At the antidiuretic stage in the morning, urine osmolality continued to rise gradually, in spite of the water loading, to the level of 666 mOsm/liter. At the water restriction test, the urine was concentrated only to the same level of 600-700mOsm/liter. At the ascending stage of urine osmolality, exogenously injected pitressin showed little antidiuretic effect, although the kidney was able concentrate urine to the higher level later. In the morning, 3 liters of 5% glucose infusion failed to produce a marked diuresis in spite of extreme plasma dilution and expansion. Furosemide immediately induced diuresis even in the morning and the kidney recovered its ability to respond to pitressin. Glucocorticoid also improved the diuretic pattern in the morning, but a latent period of about 2 hr was always observed before the appearance of the effect. What happened during this latent period was unclear, but it was interesting to note that a mechanism similar to that which induces diuretic response seemed to occur without glucocorticoid at night.