Comparative Study of Ringer’s Lactate and 6% Hydroxyethyl Starch as Preloading Fluid for Prevention of Hypotension Following Subarachnoid Block

Background and Objective: To compare the efcacy of Ringer's lactate and 6% hydroxyethyl starch in reducing the incidence and severity of hypotension after subarachnoid block. Design: Prospective and randomized comparative study. Materials and methods: 100 patients in the age group of 20 to 60 years of ASA Grade I scheduled for elective lower abdominal and lower limb surgeries were randomly allocated into two groups. CRL-Group: received 20ml/kg of Ringer's lactate. COL-Group: received 10 ml/kg of HES 6%20 minutes prior to spinal anaesthesia. Pulse rate, systolic, diastolic and mean arterial blood pressure was recorded at an interval of every minute up to 5 minutes, every 5 minutes up to 60 minutes duration. Results: The incidence of hypotension was 86% in CRL-Group, and 6% in COL-Group, which was statistically signicant. The Mephentermine bolus requirements were less in COL-Group (3 of 50 patients) when compared to CRL-Group (43 of 50 patients). None of them have allergic reactions in COL-Group. Interpretation and Conclusion: It was observed from our study that 6% HES group reduces incidence of hypotension after subarachnoid block, thus requiring lesser mean dose requirements of Mephentermine when compared to Ringer's lactate group. 6% HES is effective and safer when compared with Ringer's lactate in preventing hypotension in patients undergoing surgeries under SAB. In conclusion we found that colloids when compared with crystalloids reduce the incidence of spinal anaesthesia induced hypotension.