Kidney international
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Kidney international · Nov 2005
ReviewEvolving concepts in the quantitative analysis of the determinants of the plasma water sodium concentration and the pathophysiology and treatment of the dysnatremias.
The physiologic and clinical implications of the empirical formula originally discovered by Edelman et al [J Clin Invest 37:1236-1256, 1958] relating the plasma water sodium concentration ([Na(+)](pw)) to the total exchangeable sodium (Na(e)), total exchangeable potassium (K(e)), and total body water (TBW) have recently been elucidated. It is quite remarkable that the full significance of the Edelman equation discovered almost 50 years ago had remained unrecognized by clinicians and physiologists until recently. ⋯ Even more remarkably, based only on the theoretical principles of Gibbs-Donnan and osmotic equilibrium, all the physiologic parameters that determine the magnitude of the [Na(+)](pw) can be incorporated into a simple conceptual and mathematical framework that sheds light on a broad of range of seemingly unrelated topics that have heretofore been treated separately clinically, including (1) effect of changes in the mass balance of Na(+), K(+), and H(2)O on the [Na(+)](pw); (2) modulation of [Na(+)](pw) in hyperglycemic states; (3) definition of an isonatric solution; (4) current formulas used to quantitate electrolyte-free water excretion; (5) complex role of K(+) in modulating the [Na(+)](pw); and (6) quantitative analysis of the generation and treatment of the dysnatremias. Moreover, this analysis has also proven to be an indispensable tool for deriving new formulas to aid the clinician in both interpreting the pathogenesis and treating the dysnatremias.
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Kidney international · Nov 2005
Anemia and mortality in hemodialysis patients: accounting for morbidity and treatment variables updated over time.
The objective of this study was to gain insight into the associations of anemia with mortality among maintenance hemodialysis (HD) patients and patient subgroups by an analysis that more comprehensively represents hemoglobin (Hb) level, morbidity, and treatment characteristics over time than was possible in prior observational studies. ⋯ Our findings confirm the associations of Hb levels > or =11 g/dL with longer survival among maintenance HD patients, but show no additional survival advantage for patients with Hb levels > or =12 g/dL. Further investigation of the relationships among anemia, treatment of anemia, and survival is warranted.