Renal support in critically ill patients: low-dose dopamine or low-dose dobutamine?
OBJECTIVE
Low-dose dopamine has been used in critically ill patients to minimize renal dysfunction without sufficient data to support its use. The aim of this study was to determine whether low-dose dopamine improves renal function, and whether dobutamine, a nondopaminergic inotrope, improves renal function.


METHODS
Prospective, randomized, double-blind trial.


METHODS
Twenty-three patients at risk for renal dysfunction were entered into the study. Five patients were later withdrawn. Study data for the remaining 18 patients were: mean age 55 yrs; mean Acute Physiology and Chronic Health Evaluation (APACHE) II score of 18; mean weight 71 kg). The following conditions were present: mechanical ventilation (n = 17 [inverse-ratio ventilation, n = 6]); inotrope administration (n = 11); sepsis (n = 13); and adult respiratory distress syndrome or multiple organ failure syndrome (n = 9).


METHODS
The study patients were administered dopamine (200 micrograms/min), dobutamine (175 micrograms/min), and placebo (5% dextrose) over 5 hrs each in a randomized order. Ventilator settings, fluid management, and preexisting inotropic support were not altered during the study.


RESULTS
Systemic hemodynamic values and indices of renal function (4-hr urine volume, fractional excretion of sodium, and creatinine clearance) were measured during the last 4 hrs of each infusion. Dopamine produced a diuresis (145 +/- 148 mL/hr) compared with placebo (90 +/- 44 mL/hr; p < .01) without a change in creatinine clearance. Conversely, dobutamine caused a significant increase in creatinine clearance (97 +/- 54 mL/min) compared with placebo (79 +/- 38 mL/min; p < .01), without an increase in urine output.


CONCLUSIONS
In stable critically ill patients, dopamine acted primarily as a diuretic and did not improve creatinine clearance. Dobutamine improved creatinine clearance without a significant change in urine output.
Duke
G J
GJ
Department of Anesthesia and Intensive Care, Preston & Northcote Community Hospital, Victoria, Australia.
Briedis
J H
JH
Weaver
R A
RA
D018806:APACHE; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003404:Creatinine / Q000097:blood; D016638:Critical Illness / Q000628:therapy*; D004280:Dobutamine / Q000008:administration & dosage*; D004298:Dopamine / Q000008:administration & dosage*; D004311:Double-Blind Method; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D007668:Kidney / Q000187:drug effects / Q000503:physiopathology; D008875:Middle Aged; D011446:Prospective Studies; D017582:Renal Replacement Therapy; D013997:Time Factors
D004280:Dobutamine; D003404:Creatinine; D004298:Dopamine