Dopamine administration in oliguria and oliguric renal failure

Oliguric renal failure significantly worsens the prognosis of many critical illnesses, particularly in patients with respiratory failure. In 52 patients, a continuous infusion of dopamine, 1.5–2.5 μg/kgμmin, was administered when creatinine clearance (Cer) fell below 40 ml/ min and urinary output was less than 1 ml/kgμh despite normal intravascular volume. In 18 patients, a continuous infusion of furosemide (3–5 mg/kgμday) was also administered. Daily, two 3-h collections of urine and blood specimens were obtained to determine Ccr, osmolar clearance (Cosm), free water clearance (CHO2) and excreted fraction of filtered sodium (FENa); one collection was made during dopamine infusion and one while the infusion was suspended. Cardiac output and pulmonary venous admixture were also measured. The authors obtained 199 urine collections in 52 patients; considering the aggregate patient population, urinary output increased by 42.3% (30.2 ± 3.45 (SEM) ml/h), on dopamine infusion. Cosm, FENa, and Ccr were also higher on dopamine. CH2O and hemodynamic variables were not altered by dopamine infusion.When patients were stratified on the basis of mechanical veritilatory support, Ccr and furosemide administration, dopamine infusion essentially caused the same changes in the variables studied as described for the aggregate patient population. Diuresis and sodium excretion increased significantly on dopamine even in those patients receiving furosemide infusion.The authors conclude that fluid and osmolar load can be eliminated more effectively in critically ill patients with continuous infusion of 1.5–2.5 μg/kgμmin of dopamine.