Association of hypotension with hyperreninemic hypoaldosteronism in the critically ill patient.

Paradoxical suppression of plasma aldosterone (PA) despite increased plasma renin activity (PRA) has recently been noted in some critically ill patients. To determine the prevalence of this entity and to identify possible etiologic factors, we studied 100 consecutive patients admitted to a medical intensive care unit (ICU). Twenty-two of 100 ICU patients had hyperreninemia and inappropriately reduced PA concentrations, with a PA to PRA ratio less than the 98th percentile of the control population. Comparison of clinical data of these 22 patients with the other hyperreninemic ICU patients revealed no differences in electrolyte concentrations, nutrition, medications, or survival. However, persistent hypotension was much more frequent (91% v 53%). Thus, impaired aldosterone response to hyperreninemia has a high prevalence among critically ill patients and may be related to adrenal damage from persistent hypotension.