Acute deterioration in renal function in patients with preexisting renal insufficiency.

[ill]Roy First, MD, Associate Professor of Medicine: Sud[ill]en deterioration in the clinical condition of a patient with [ill]hronic renal insufficiency may occur frequently as a result [ill]f a superimposed acute illness with consequent deteriora[ill]ion in renal function. It is important to identify and treat [ill]ny condition that aggravates the underlying renal disease [ill] has adverse effects on renal function. 1 Table 1 illustrates those conditions causing acute deterio[ill]tion of renal function in the patient with azotemia or [ill]emia. 1 Reduced renal perfusion commonly results from [ill]xtracellular fluid volume depletion. The use of potent [ill]iuretic agents, eg, furosemide or ethacrynic acid, coupled [ill]ith the injudicious restriction of dietary sodium, is a [ill]mmon cause of salt and water depletion, as are gastroin[ill]stinal (GI) losses of sodium and water by vomiting, [ill]arrhea, or both from intercurrent GI disturbances or [ill]om the uremia per se. Subtle dehydration also may result [ill]hen the patient, who is