Background: Various methods have been devised to prevent hypotension, a very common complication of subarachnoid block(SAB). This study was conducted to evaluate the efficacy of combined use of crystalloid preloading and vasoconstrictor for prevention of hypotension due to SAB, when compared to crystalloid preloading. Methods: 100 adult patients of physical status ASA I and II scheduled to undergo elective surgical procedure on lower abdomen under SAB were divided into two groups of 50 each. Crystalloid group: Preloaded with Ringer’s lactate: 15 ml/KBW over 20 min before SAB. Combination group: Preloaded with 7.5 ml/KBW of Ringer’s lactate over 10 min preceding SAB, followed by IV bolus of 2.5 mg of ephedrine in the first and second minute and 0.5mg ephedrine at the end of each minute for next 18 minutes after SAB. In each patient, pulse rate and systolic blood pressure were recorded. Subsequently, the recordings were done at 5th, 10th, 15th, 20th, 25th and 30th minute after SAB. Results: The incidence and severity of hypotension was maximum (18%) in the crystalloid group and less (2%) in the combination group. The difference in incidence of hypotension among two groups was statistically significant( P<0.05). The incidence of reactive hypertension was more in combination group (4%) than the crystalloid group (2%) and was statistically significant (P<0.05). The incidence of nausea (4 %) and vomiting (2%) was seen in combination group whereas there were no incidence of the same in crystalloid group. Conclusion: combination therapy with the reduced volume of crystalloid preloading and reduced dose of vasoconstrictor is an effective preventive measure against hypotension due to SAB and provides better haemodynamic stability when compared to the use of preloading alone. 

Keywords: Subarachnoid Block; Hypotension; Crystalloid Preloading; Vasoconstrictor; Ephedrine.