Hyperparathyroidism evaluation

A. E. Sizemore, G. W. Arnaud, C. D. "Etiology of Hyperparathyroidism and Bone Disease During Chronic Hemodialysis. III. Evaluation of Parathyroid Suppressability". J. Clin. Invest. (1973), 52, 173-180. 

Thallium ( Tl) Chloride. Thallium chloride is the only radiopharmucculical of lhallium-201 currently in use. The most common clinical u.ses of this radiotracer are for the evaluation of myocardial perfusion and myocardial viability. In recent years, thallium-201 has also been u.sed to evaluate a variety of types of cancer as well as hyperparathyroidism. 

The initial laboratory evaluation is directed toward the assessment of renal function and measurement of serum albumin and magnesium concentrations. Serum intact PTH concentrations are low or inappropriately normal in hypoparathyroidism and elevated in pseudohypoparathyroidism. Vitamin D deficiency is characterized by low serum 25(OH)D> high PTH (secondary hyperparathyroidism), and high serum alkaline phosphatase (ALP). 

Measurement of 1,25 (OH) 2D is usefiil in detecting inadequate or excessive hormone production in the evaluation of hypercalcemia, hypercalciuria, hypocalcemia, and bone and mineral disorders (Box 49-10). Because activated macrophages convert 25(OH)D to l,25(OH)2D, serum concentrations of 1,25(OH)2D are often increased in sarcoidosis, tuberculosis, other granulomatous diseases. Rarely is lymphoma associated with increased concentrations of 1,25(0H)2D. Concentrations of l,25(OH)2D are elevated in vitamin D-dependent rickets type II and in l,25(OH)2D intoxication, and may be elevated in primary hyperparathyroidism. Fatients with primary hyperparathyroidism and... 

Koivula T. Intact parathyroid hormone, ionized calcium and calcium infusion test in the evaluation of hyperparathyroidism in chronic renal failure. 

Iron deficiency is the most common cause of resistance to erythropoietic therapy. Evaluation and treatment of iron deficiency should occur prior to initiation of erythropoietic therapy as previously discussed (see Figs. 44—1 and 44—2). Inflammation (localized or systemic infection, active inflammatory disease, or surgical trauma) is associated with defective iron utilization known as reticuloendothelial block. Reticuloendothelial block is characterized by a reduction in iron delivery from body stores to the bone marrow, and is generally refractory to iron therapy. Failure to respond to erythropoietic therapy requires evaluation of other factors causing resistance, such as infection, inflammation, chronic blood loss, aluminum toxicity, hemoglobinopathies, malnutrition, and hyperparathyroidism. Erythropoietic therapy may be continued in the infected or postoperative patient, although increased doses are often required to maintain or slow the rate of decline in Hgb/Hct. Deficiencies in folate and vitamin Bi2 should also be considered as potential causes of resistance to erythropoietic therapy, as both are essential for optimal erythropoiesis. Patients on hemodialysis or peritoneal dialysis should be routinely... 

Block GA, Port FK. Re-evaluation of risks associated with hyperphosphatemia and hyperparathyroidism in dialysis patients Recommendations for a change in management. Am J Kidney Dis 2000 35 1226-1237. 

The homeostasis of calcium in the blood is partly maintained by calcium excretion. Calcium is excreted in bile, urine, feces, and milk. Except during lactation, the kidney and intestine provide the main excretory paths for calcium. The exact amount of calcium that is excreted by way of the intestine is difficult to evaluate because of the large amounts of unabsorbed calcium normally present in the feces (6.5-8 mg/100 ml). Under normal conditions, it seems that little calcium is excreted through the intestine. The renal threshold for calcium is below the minimal levels of calciuni in the blood, so the glomeruli constantly remove calcium from the circulating blood. Most of the excreted calcium is reabsorbed in the tubules. In chronic renal failure, excessive amounts of calcium are lost in the urine, leading to decalcification of the bones and a form of secondary hyperparathyroidism. 

Systematic reviews In a meta-analysis of nine trials to evaluate the effectiveness of paricalcitol in the treatment of secondary hyperparathyroidism and proteinuria in chronic kidney disease patients, there was insufficient power to detect adverse events [70 ]. 

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