THE RENAL EFFECTS OF LOW-DOSE DOPAMINE IN THERMALLY INJURED PATIENTS

The renal effects of low-dose dopamine (LDD) therapy in hyperdynamic t hermally injured patients are unknown. We investigated the renal effec ts of LDD in ten burn patients (mean +/- SEM age and %total body surfa ce burned: 30.2 +/- 3.3 years and 53.4% +/- 7%) and six controls (mean age; 20.2 +/- 0.5 years). Administration of LDD significantly increas ed glomerular filtration rate, effective renal plasma flow, sodium exc retion, and urine flow in the controls and effective renal plasma flow , urine flow, heart rate, and cardiac index in the patients. The chron otropic effect of dopamine appears to be a principal contributor to th e patients' increased effective renal plasma flow. Sodium excretion wa s increased by LDD only in the patients in whom the pre-dopamine sodiu m excretion exceeded 5 mEq/h. Lack of a consistent natriuretic effect and the consistent chronotropic effect suggest that the routine use of low-dose dopamine in burn patients is unwarranted. The side effects t hat attend the desired response determine clinical use, i.e., the pote ntial for blood flow redistribution and increased cardiac work demands must be balanced against increased renal plasma flow and natriuresis.