Management of Perioperative Hypertension Comparative Study Between Isradipine and Hydralazine

Abstract

Isradipine is a dihydropyridine derivative with a potent arteriolar vasodilator property, negative chronotropic action, with only negligible effects on contractility and conduction. This specificity for intrinsic vascular effects makes isradipine useful for the correction of acute increase in systemic vascular resistance particularly in patients with ischemic heart disease. Hydralazine was one of the first antihypertensive drugs to be marketed. However, the drug initially was used infrequently because of tachycardia and tachyphylaxis. Hydralazine causes direct relaxation of arteriolar smooth muscles. With better understanding of the compensatory cardiovascular responses that accompany the use of arteriolar vasodilators, hydralazine was combined with P-adrenergic blockers and diuretics with greater therapeutic success. In the present study, we studied and compared the effects of isradipine given either by IV bolus injection or by continuous infusion and hydralazine in 90 patients with perioperative hypertension (MAP > 110 mmHg). The patients were divided into 3 groups: Group I: 30 patients with poorly controlled hypertension presented for emergency non-cardiac surgery. Group II: 30 patients with intraoperative hypertensive episodes undergoing different non-cardiac operations, after administration of supplementary dose of analgesia (fentanyl). Group III: 30 patients with preeclampsia-eclampsia presented for emergency cesarean section.