The approach to a patient with acute polyuria and hypernatremia: a need for the physiology of McCance at the bedside

We present a case to illustrate the importance of emphasizing elementary ph ysiology to deduce the basis for the acute onset of polyuria and hypernatre mia. An imaginary consultation with Professor McCance is utilized to illust rate how a clinician-physiologist would have explained why these abnormalit ies developed and how they should have been treated. His approach began wit h a consideration of the most impressive abnormality. His analysis relied h eavily on deductions and the anticipation of the expected responses to a st imulus in quantitative terms. The goals of therapy became evident after he performed mass balance calculations. Professor McCance would not understand why modern clinicians abandoned this form of analysis. (C) 2001 Elsevier S cience B.V. All rights reserved.