Comparison of Intravenous Anti-hypertensives for Preoperative Blood Pressure Control in Hypertensive Disorders of Pregnancy and Effect of Oral Labetalol.

Background And Aims: Intravenous hydralazine and labetalol are recommended as first-line anti-hypertensives for controlling severe hypertension in pregnancy. Our study aimed at identifying the most effective drug with minimum side effects for preoperative management of severe hypertension in parturients scheduled for Caesarean delivery (CD). We also studied the effect of these drugs on patients already on oral labetalol in the antenatal period.

Methods: A prospective observational study was done on 162 hypertensive parturients scheduled to undergo emergency CD who received hydralazine or labetalol in the preoperative period. Demographic data, booking status, hemodynamic data, time taken to reach adequate control of blood pressure (BP), drug efficacy, the incidence of persistent hypertension, adverse effects associated with the drugs, and maternal and fetal outcomes were noted.

Results: The time taken for the control of BP was similar with both drugs (p-value = 0.425). The mean number of doses required to achieve target BP was significantly less with hydralazine compared to labetalol (p-value = 0.009). Patients on tablet labetalol in the antenatal period were poorly controlled when put on the same drug intravenously but had better control with hydralazine (p-value = 0.005). The incidence of persistent hypertension was lower in patients treated with hydralazine compared with labetalol (p-value = 0.008).

Conclusion: Both drugs took a similar time for BP control. However, hydralazine was more efficacious, produced adequate control of BP in a higher number of patients, and had a lower incidence of persistent hypertension.