The effects of fenoldopam on coronary conduit blood flow after coronary artery bypass graft surgery.

To quantify the effects of fenoldopam, 0.1 microg/kg/min, on left internal mammary artery (LIMA) and saphenous vein blood flow after coronary anastomosis.

Prospective, randomized, double-blind, placebo-controlled trial.

University teaching hospital, single institution.

Thirty-one American Society of Anesthesiologists III patients undergoing elective coronary revascularization.

A perivascular ultrasonic flow probe (Linton Instrumentation, Norfolk, UK) was placed around the LIMA and saphenous vein graft after coronary anastomosis.

Immediately before and at 5-minute intervals for 15 minutes after starting the infusion, blood flow was measured in the LIMA and one saphenous vein graft using a transit time ultrasonic flow probe. Heart rate, blood pressure, and central venous pressure were documented at these time points. Administration of fenoldopam, 0.1 microg/kg/min, did not alter heart rate or blood pressure. A small, nonsignificant increase in LIMA blood flow occurred during the 15-minute study period (30 +/- 12 to 35 +/- 10 mL/min) in patients who received fenoldopam. No significant changes occurred in the placebo group.

The findings indicate that fenoldopam, 0.1 microg/kg/min, did not influence coronary conduit blood flow to a clinically significant extent. The small increase in LIMA blood flow may be of greater importance in high-risk patients or in the prevention of coronary arterial spasm.