Low-dose Bupivacaine with Dexmedetomidine Prevents Hypotension After Spinal Anesthesia

Background: We assessed whether intrathecal low-dose bupivacaine with dexmedetomidine could reduce the incidence of spinal anesthesia (SA)-related hypotension. Methods: In total, 47 patients undergoing urological or orthopedic surgery under SA were randomized into two groups. SA was induced using 12.5 mg of hyperbaric bupivacaine alone (Group B; n = 24 patients) or 6 mg of hyperbaric bupivacaine plus 4 μg of dexmedetomidine and 0.3 ml of saline (Group BD; n = 23 patients). At 10 min after SA, dexmedetomidine was infused in both groups at a loading dose of 0.5 µg/kg, administered over 10 min, and then maintained at a dose of 0.2 µg/kg/h for 40 min. Results: The incidence of hypotension was significantly higher in Group B than in Group BD (50.0 vs. 17.4%, P = 0.018). The amount of ephedrine used to treat hypotension was significantly higher in Group B than in Group BD (median [range], 3 [0–30] vs. 0 [0–12] mg, P = 0.014). Conclusion: Low-dose bupivacaine plus dexmedetomidine SA reduced the incidence of hypotension compared to conventional bupivacaine SA.