Impedance cardiography assessed treatment of acute severe pregnancy hypertension: a randomized trial

Using noninvasive bedside impedance cardiography (ICG), we compared the effectiveness and the hemodynamic impact of intravenous labetalol versus hydralazine for the reduction of acute-onset severe hypertension to ACOG-recommended blood pressure levels (ACOG Committee Opinion 514).

In this prospective randomized pilot study of acutely severe systolic hypertension (≥160 mmHg), pregnant women received either labetalol (L) or hydralazine (H) intravenously and underwent thoracic ICG before and after treatment. Data analysis were performed using STATA software (StataCorp LP, College Station, TX); data are expressed as mean ± SD.

About 29 patients completed the study. There was no significant difference in mean arterial pressure (MAP) between groups [H = 119.4 mmHg, L = 117.7 mmHg, mean difference (MD) = 1.73); the estimated MD between baseline and follow-up ICG was -9.17 (p = 0.001, 95% CI: -14.39 to -3.95). There were no significant differences in total peripheral resistance (TPR) between groups (H = 1771.3, L = 1976.97, MD = 205.62) or cardiac output (CO) between groups (H = 5.7, L = 5.1, MD = 0.64) or a significant MD between these at baseline and follow-up.

Both drugs performed similarly to achieve ACOG-recommended initial blood pressure reduction safely without side effects or excessive acute hemodynamic profile correction toward normal pregnancy values.