Effect of combined infusion of nitroglycerin and nicardipine on femoral-to-radial arterial pressure gradient after cardiopulmonary bypass.

Nitrates and calcium channel blockers are frequently administered during cardiac surgery. We simultaneously measured femoral arterial pressure and radial arterial pressure to investigate whether nitrates, in conjunction with calcium channel blockers, would influence the central-to-peripheral arterial pressure gradient. Combined nitroglycerin and nicardipine infusion during cardiac surgery involving coronary artery bypass grafting or valve replacement resulted in a significant increase above baseline levels in the femoral-to-radial arterial pressure gradient at 60 min after cardiopulmonary bypass. In control patients there was no significant increase in the femoral-to-radial arterial pressure gradient at 60 min after completion of cardiopulmonary bypass. A subsequent study in patients given nitroglycerin and nicardipine identified that the difference in the systolic arterial pressure between femoral and radial arteries was observed 15, 60, and 120 min after completion of cardiopulmonary bypass. However, there was no difference in the mean arterial pressure between femoral and radial arteries throughout the same period. We conclude that combined infusion of nitroglycerin and nicardipine, a new calcium channel blocker, intensifies the magnitude and duration of the femoral-to-radial arterial pressure gradient after cardiopulmonary bypass.