Critical Interpretation of Adequacy Parameters in Peritoneal Dialysis and Hemodialysis

T he measurement of solute clearance has historical roots for the nephrologist in the work of Homer Smith, and such measurement has contributed ma terially to the quantitative understanding of the performance of the native kidney in both glomerular and tubular function (1). The logic, then, of designing an analogous term for use with the artificial kidney was persuasive for Wolf et al (2). While initially helpful, the interpretation of artificial kidney clearance has become overly complex owing to the proliferation of artificial kidney techniques with subsequent "customization " of the clearance term for each technique. The customizations have led to confusion and conceptual errors in intermodality comparisons of performance and outcome when clearance-based terms such as "Kt/V urea" are used to quantify the amount of therapy rendered (3). In this presentation, I will review the basic definitions of