Dopamine-related polyuria in patients with gram-negative infection

Two patients developed polyuria with natriuresis while receiving intravenous dopamine hydrochloride for the treatment of hypotension. Both patients had Gram-negative pneumonia and both had evidence of extracellular volume depletion that was considered to be a result of the dopamine-induced polyuria. Following restoration of extracellular volume and withdrawal of dopamine therapy, both patients became normotensive and required no vasopressors. The diuretic action of dopamine, which persisted despite the severe intravascular volume contraction and perpetuated the hypotensive state in these two patients, is not well understood. The Gram-negative infection could play an important role possibly by enhancing the effect of dopamine on the renal vasculature.