Effect of Injection Speed of Heavy Bupivacaine in Spinal Anesthesia on Quality of Block and Hemodynamic Changes

Abstract

Background and Aims: Spinal anesthesia is a technique widely used for gynecological, lower abdominal, pelvic and lower limb procedures. Even though it causes a profound nerve block, it is associated with profound hypotension. Aims of the Study: To assess the effect of the speed of injection of heavy bupivacaine on quality of block and hemodynamic changes in patients undergoing gynecological surgeries under spinal anesthesia. Methods: This was a prospective randomized study conducted on 40 patients. Group F patients were given 3.2 mL of 0.5% heavy bupivacaine intrathecally in 15 s and Group S patients were given the same drug over 60 s. The time to achieve T10 dermatomal block, maximum block height, block height at 5 min were recorded. Heart rate (HR), systolic, diastolic blood pressures, and mean arterial pressures (MAP) were also recorded at different time points. Results: HR, systolic BP, diastolic BP, and MAPs and mean block height at 5 min were comparable between the two groups at all time points. The time to achieve T10 dermatome block was significantly faster in Group F (1.85 ± 1.14 min) as compared to Group S (3.98 ± 1.58 min). Majority of patients in Group F (65%) had a maximum block up to T6 and those in Group S (45%) had a block upto T4. The usage of vasopressors was found to be significantly higher in Group F compared to Group S with P = 0.041. Conclusion: Using faster speed of injection of heavy bupivacaine during spinal anesthesia can lead to faster achievement of blockade but with significantly higher usage of vasopressors.