[The effect of nicardipine hydrochloride upon the pulmonary arterial pressure].

This study examines the effects of induced hypotension with intravenous administration of nicardipine hydrochloride (NIC) upon pulmonary arterial pressure (PAP) undergoing modified radical mastectomy with neuroleptanesthesia (NLA-group; 3 cases) and inhalation anesthesia (N2O+ isoflurane; GOI-group; 3 cases). Systolic arterial pressure was reduced and maintained at 80 mmHg. During and after induced hypotension in NLA-group, heart rate (HR), cardiac index, pulmonary arterial pressure (PAP) increased remarkably. On the other hand, systemic vascular resistance index was reduced. In GOI group, no significant changes were seen in PAP. The acceleration of the autonomic baro-reflex induced by decreased blood pressure produced by NIC may be depressed under anesthesia to initiate this difference in response of HR to NIC. The data indicate that this depressive effect of NLA on this reflex is weak, and NIC is a potent systemic vasodilator with hyperdynamic hemodynamic effects in addition to an increase in right ventricular function, and PAP was increased.