Hemodynamic effects of intravenous nicardipine in severely pre-eclamptic women with a hypertensive crisis

Objective Nicardipine permits rapid control of blood pressure in women with severe pre-eclampsia (PE) and hypertensive crisis. Our objective was to investigate its maternal and fetal hemodynamic effects.
Methods Ten severely pre-eclamptic pregnant women who required intravenous nicardipine for severe hypertension were included in this prospective observational trial. Maternal macrocirculation was assessed by transthoracic echocardiography. Maternal microcirculatory perfusion was examined sublingually with the sidestream dark field imaging technique. Fetal hemodynamics were assessed by Doppler examinations of the uteroplacental and fetal circulations. Maternal cardiac output, total vascular resistance, mitral E/A ratio and capillary heterogeneity index, uterine artery pulsatility index and fetal cerebroplacental ratio were considered primary outcomes. Paired measurements, obtained before administration of nicardipine infusion and after stabilization of blood pressure, were compared.
Results Administration of nicardipine significantly reduced the mean arterial blood pressure (median difference, 26 mmHg; P = 0.002) and total vascular resistance (median difference, 791 dynes × s/cm5; P = 0.002) in all included women. This induced a reflex tachycardia with consequent increase in cardiac output of 1.55 L/min (P = 0.004). There were no significant changes in the other determinants of maternal or fetal hemodynamic parameters.
Conclusions Nicardipine effectively reduces blood pressure through selective afterload reduction that triggers an increase in cardiac output, without affecting maternal diastolic function, or microcirculatory, uteroplacental or fetal perfusion. This hemodynamic response is uniform and predictable. Fetomaternal cardiovascular profiling can be achieved by combining transthoracic echocardiography with obstetric Doppler.