Comparison of intravenous hydralazine and intravenous labetalol in the management of severe hypertensive disorders of pregnancy: a tertiary care centre study

Abstract

INTRODUCTIONHypertensive disorders complicate 5 to 10 per cent of all pregnancies, and together they are one member of the deadly triad along with haemorrhage and infection that contributes greatly to maternal morbidity and mortality. Of these disorders, the pre-eclampsia syndrome, either alone or superimposed on chronic hypertension, is the most dangerous.1 Although, there is a lack of agreement regarding the blood pressure levels at which to initiate antihypertensive therapy, there is no debate that severe hypertension (i.e. systolic pressure >160 mmHg and /or diastolic pressure >110 mmHg) should be treated to prevent maternal and the consequent fetal complications. 2Women with pre-eclampsia, without differentiating the severity of the disease, are predisposed to develop complications such as abruptio placentae, disseminated intravascular coagulation, cardiopulmonary complications (pulmonary edema), cerebral hemorrhage, hepatic rupture, hepatic insufficiency and death. The fetal complications are the reduction of the oxygen and nutrient supply leading to fetal growth restriction (FGR), ABSTRACTBackground: Severe hypertension in pregnancy (SBP ≥160 mmHg &/or DBP ≥ 110 mmHg) must be treated judiciously to prevent maternal and fetal complications. The study was conducted to compare the efficacy, adverse effects, maternal and fetal outcome between Hydralazine and Labetalol which are the most commonly used drugs for the purpose. Methods: In a prospective study, 130 pregnant patients each with severe hypertension presenting to SMGS Hospital Jammu were randomized in 2 groups and administered hydralazine or labetalol intravenously. The efficacy of the two drugs was measured in terms of number of doses required to obtain target BP and the timing to achieve the same. The incidence of adverse effects, maternal and fetal outcomes were also compared. Comparisons among the two groups was performed by using independent Student's t test for normally distributed variables, Fishers' exact test, and Pearson Chi Square test for categorical variables. The level of significance was set at p<0.05 for all analysis. Results: There was no statistical difference between the two drugs in terms of efficacy. Significantly more low-birth weight infants were born in the hydralazine group. Also, the adverse effects were significantly more in the hydralazine group. Conclusions: Both hydralazine and labetalol can be used to treat hypertensive emergencies of pregnancy but hydralazine is associated with more side effects.