Renal hemodynamics during norepinephrine and low-dose dopamine infusions in man.
Crit Care Med
; 24(7): 1150-6, 1996 Jul.
Article
in En
| MEDLINE
| ID: mdl-8674327
ABSTRACT
OBJECTIVE:
To characterize the effects of pressor doses of norepinephrine and low-dose dopamine (3 micrograms/kg/min) on renal hemodynamics in man, as well as to determine the clinical relevance of combining dopamine with norepinephrine.DESIGN:
Prospective, single-blind, randomized study.SETTING:
Clinical research unit of a tertiary care hospital. SUBJECTS. Six healthy male volunteers ranging in age between 20 and 28 yrs.INTERVENTIONS:
The subjects were assigned randomly to four treatments (1 wk apart) in which renal hemodynamics and electrolyte excretion were assessed. Treatments consisted of 180-min infusions of the following a) 0.9% sodium chloride (control); b) pressor doses of norepinephrine; c) dopamine at 3 micrograms/kg/min; and d) pressor doses of norepinephrine and dopamine at 3 micrograms/kg/min. Pressor doses of norepinephrine was defined as doses required to increase mean arterial pressure (MAP) by 20 mm Hg. MEASUREMENTS AND MAINRESULTS:
Glomerular filtration rate and renal blood flow were derived from inulin and para-aminohippurate clearances, respectively. Urine output and urine solute excretion were also determined. The mean norepinephrine dose required to increase MAP by 22 +/- 2 mm Hg was 118 +/- 30 ng/kg/min (range 76 to 164). After the addition of dopamine, similar doses of norepinephrine resulted in an MAP increase of 15 +/- 4 mm Hg. Glomerular filtration rate and urine output were comparable under all conditions. The infusion of norepinephrine decreased renal blood flow from 1241 +/- 208 to 922 +/- 143 mL/min/1.73 m2 (p = .03). The addition of dopamine returned renal blood flow to baseline values. The clearance of urine sodium increased significantly with the infusion of dopamine alone (p = .03). All subjects completed the four treatment periods. Adverse events, manifested mostly as palpitations and flushing, were rare and self-limiting.CONCLUSIONS:
The addition of dopamine (3 micrograms/kg/min) to pressor doses of norepinephrine normalized renal blood flow in healthy volunteers. These hemodynamic changes were not reflected in urine output and glomerular filtration rate; hence, these monitoring parameters may be unreliable indicators of renal function in the setting of vasopressor therapy. In addition, systemic effects were observed with dopamine (3 micrograms/kg/min), as indicated by a decrease in MAP.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Renal Circulation
/
Vasoconstrictor Agents
/
Dopamine
/
Norepinephrine
/
Hemodynamics
Type of study:
Clinical_trials
Limits:
Adult
/
Humans
/
Male
Language:
En
Journal:
Crit Care Med
Year:
1996
Document type:
Article
Affiliation country:
Canada