Serum aldosterone concentrations and urine output in oliguric intensive care unit patients receiving low-dose dopamine.
OBJECTIVE
To determine whether the diuretic and natriuretic effects of low-dose dopamine (2.5 micrograms/kg/min) are associated with changes in serum aldosterone concentration.


METHODS
Prospective clinical study.


METHODS
Surgical intensive care unit (SICU) of a university hospital.


METHODS
Oliguric (urine output < 0.5 mL/kg/h) SICU patients. All patients were resuscitated to pulmonary artery occlusion pressure > 10 mm Hg, mean arterial pressure > 65 mm Hg, and cardiac index > 2.5 L/min/m2. Patients with a serum creatinine concentration > 176.8 mumol/L (2.0 mg/dL), those who received diuretics within 12 hours prior to entry into the study, and renal transplant recipients were excluded.


METHODS
Hourly urine output (mean +/- SD) was recorded 2 hours before and for 6 hours after the initiation of low-dose dopamine. Urine sodium and serum aldosterone concentrations were obtained prior to and 6 hours after the start of low-dose dopamine.


RESULTS
Fifteen patients were enrolled in the study. Urine output (mean +/- SD) increased from 0.31 +/- 0.11 mL/kg/h before to 0.80 +/- 0.34 mL/kg/h following low-dose dopamine (p < 0.01). Urine sodium concentrations increased from 46 +/- 32 mmol/L baseline to 72 +/- 53 mmol/L following low-dose dopamine (p < 0.05), and serum aldosterone concentrations decreased from 415.82 +/- 341.48 pmol/L prior to low-dose dopamine infusion to 256.04 +/- 204.17 pmol/L (p < 0.05). Cardiac output, pulmonary artery occlusion pressure, mean arterial pressure, and heart rate did not change.


CONCLUSIONS
Low-dose dopamine significantly increases urine output and urine sodium excretion in oliguric, critically ill, surgical patients, and is associated with a decrease in serum aldosterone concentration. The diuretic and natriuretic effects of low-dose dopamine may be, in part, related to a dopamine-mediated inhibition of aldosterone secretion.
Dick
M
M
Department of Emergency Medicine, Ohio State University, Columbus 43210.
Dasta
J F
JF
Choban
P S
PS
Sinha
R
R
Flancbaum
L
L
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000450:Aldosterone / Q000097:blood* / Q000652:urine; D004298:Dopamine / Q000008:administration & dosage*; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009318:Natriuresis / Q000187:drug effects; D009846:Oliguria / Q000097:blood* / Q000652:urine; D011446:Prospective Studies; D014554:Urination / Q000187:drug effects*
D000450:Aldosterone; D004298:Dopamine