A comparison of hypotension and bradycardia following spinal anaesthesia in patients on calcium channel blockers and β-blockers

OBJECTIVES Hypotension is a common complication of spinal anesthesia and is frequent in patients with hypertension. Antihypertensive agents decrease this effect by controlling blood pressure. There are conflicting reports on the continuation of antihypertensive drugs on the day of surgery in patients undergoing spinal anesthesia. Sudden hypotension could have detrimental effect on the organ systems. This study was undertaken to compare the variation in blood pressure in hypertensive patients on β-blockers and calcium channel blockers undergoing spinal anesthesia. MATERIALS AND METHODS Ninety patients were enrolled for the study, 30 each in the control, β-blocker and the calcium channel blocker groups. RESULTS The incidence of hypotension was not different among the three groups. However, the number of times mephentermine used to treat hypotension was significant in the patients receiving calcium channel blockers while incidence of bradycardia in patients treated with β-blockers was significant (P<0.001). CONCLUSION The incidence of hypotension following spinal anesthesia is not different in patients receiving β-blockers and calcium channel blockers among the three groups.