American journal of kidney diseases : the official journal of the National Kidney Foundation
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It is commonly taught that retention of free water is the dominant factor reducing the serum sodium concentration in hyponatremia. To determine whether the concentrations of other electrolytes are similarly diluted, we identified 51 patients with hyponatremia (Na = 121 +/- 1 mmol/L [mEq/L]) and compared electrolyte and laboratory values at the time of hyponatremia with values at a time when serum sodium was in the normal range (138 +/- 1 mmol/L). The medium interval between these measurements was 12 days. ⋯ Second, both renal and extrarenal adaptive mechanisms are activated by hyponatremia that stabilizes the concentration of other ions. One of these mechanisms is cell swelling, which triggers a volume-regulatory response leading to the release of ions and water into the ECF. Other adaptive mechanisms are mediated by antidiuretic hormone (ADH) per se, and by atrial natriuretic peptide (ANP).
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Continuous venovenous hemofiltration (CVVH) has been used as an alternative to continuous arteriovenous hemofiltration (CAVH) and hemodiafiltration (CAVHD) in the management of critically ill patients with acute renal failure. This report describes our experience with the first 25 patients treated with CVVH at our institution. Vascular access was obtained through a single dual-lumen venous catheter. ⋯ No patient experienced a complication related to vascular access. Twelve of 111 total hemofilters were changed because of clot formation. CVVH was well tolerated by patients and managed efficiently by the ICU nursing staff.(ABSTRACT TRUNCATED AT 250 WORDS)
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Erythropoietin (Epo) is a glycoprotein hormone produced in the kidney that acts on erythroid progenitor cells in the bone marrow. A negative feedback system, in which tissue oxygenation controls Epo production and Epo controls red blood cell (RBC) production, provides homeostasis in oxygen delivery to body tissues. ⋯ No known second messenger system has been implicated in signal transduction from the Epo receptor. Although Epo may have some effect on mitosis in early erythroid progenitor cells, its control of RBC production appears to occur in later stages of erythroid cell development, where it prevents programmed cell death.
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High blood pressure (BP) complicates approximately 10% of all pregnancies. Hypertension in pregnancy falls into four categories: (1) preeclampsia-eclampsia, (2) chronic hypertension of whatever cause, (3) preeclampsia-eclampsia superimposed to chronic hypertension or renal disease, and (4) transient or late hypertension (gestational hypertension). Preeclampsia, the association of hypertension, proteinuria, and edema, accounts for more than 50% of all the hypertensive disorders of pregnancy and is a major cause of fetal and maternal morbidity and mortality. ⋯ Life-threatening hypertension that does not respond to more conventional therapy is an indication for the use of sodium nitroprusside. For chronic hypertension, alpha-methyldopa remains the treatment of choice; if ineffective, hydralazine or beta-blockers are suitable. Effectiveness and safety of other molecules remain elusive.
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A right adrenal tumor was found incidentally by renal echography in a 25-year-old man, who had been on hemodialysis for 4 years. Inquiry and clinical examination suggested pheochromocytoma, which was confirmed by plasma catecholamine measurements. Subsequent adrenalectomy was uneventful. Although hypertension, headache, and diaphoresis are common symptoms in a dialyzed patient, pheochromocytoma has to be eliminated in the presence of this clinical triad.