Comparison of bupivacaine plus intrathecal fentanyl and bupivacaine alone for spinal anesthesia with intravenous dexmedetomidine sedation: a randomized, double-blind, noninferiority trial

Abstract

Background and objectivesFentanyl is widely used as an intrathecal adjuvant to local anesthetics to enhance the duration of spinal anesthesia. Recent evidence suggests that intravenous dexmedetomidine prolongs the duration of spinal anesthesia. This noninferiority study evaluated whether bupivacaine alone could provide a noninferior duration of block compared with bupivacaine and fentanyl when intravenous dexmedetomidine was administered intraoperatively.MethodsFifty-six patients scheduled for total knee arthroplasty under spinal anesthesia were randomly allocated to receive either bupivacaine 13 mg with intrathecal fentanyl 20 µg (Group BF) or bupivacaine 13 mg (Group B). Both groups underwent intravenous dexmedetomidine sedation throughout the surgery (1 µg kg–1 for 10 min, followed by 0.5 µg kg–1 h–1). The primary outcome was the time to two-segment regression of the sensory block. The noninferiority margin for the mean difference was predefined as −10 min. Secondary outcomes included postoperative pain scores, analgesics consumptions, and the incidences of pruritus, nausea, and vomiting.ResultsThere was no significant difference in the two-segment regression time of sensory block (Group B 109.1±25.0 min vs Group BF 104.3±25.9 min; p=0.484). The mean difference in the two-segment regression time between the 2 groups was 4.8 min (95 % CI −8.9 to 18.6), demonstrating the noninferiority of bupivacaine alone. Secondary outcomes showed no significant differences between the two groups.ConclusionsThe duration of spinal anesthesia with bupivacaine alone is noninferior to that of bupivacaine plus fentanyl in patients receiving intravenous dexmedetomidine intraoperatively. Our results suggest that intrathecal fentanyl may not be required when intravenous dexmedetomidine is administered.Trial registration number NCT03105115.

No Difference between Spinal Anesthesia with Hyperbaric Ropivacaine and Intravenous Dexmedetomidine Sedation with and without Intrathecal Fentanyl: A Randomized Noninferiority Trial

“…The absence of intrathecal fentanyl can offer several advantages, in addition to unnecessary opioid use and medical costs. The potential risks of infection and neurotoxicity can arise in the administration of adjuvants [ 19 , 27 ]. Moreover, fentanyl is used off-label since only morphine and baclofen are approved for intrathecal administration by the Food and Drug Administration [ 27 ].…”

“…In our study, adverse effects associated with the use of intrathecal fentanyl were not significantly different from those observed in patients without additional fentanyl administration. In actual clinical practice, significant side effects are rarely encountered with the usual 20 μ g intrathecal dose, but anesthesiologists should be aware about the possible adverse effects [ 19 ]. Postoperative pain and consumption of analgesics were not significantly different between the two groups, but the duration to request for the first analgesics in Group R was 75.2 min shorter than in that in Group RF, which while not statistically significant, could be clinically meaningful.…”

“…Postoperative pain and consumption of analgesics were not significantly different between the two groups, but the duration to request for the first analgesics in Group R was 75.2 min shorter than in that in Group RF, which while not statistically significant, could be clinically meaningful. Park et al conducted a study to evaluate the effects of intrathecal fentanyl 20 μ g in spinal anesthesia with bupivacaine during dexmedetomidine sedation [ 19 ]. Their study also did not report any significant differences in the adverse effects after fentanyl administration than without additional fentanyl.…”

“…This study aimed to assess the noninferiority of the time to two-dermatomal segment regression of sensory blockade in patients who received ropivacaine compared with that of those who received ropivacaine and fentanyl. Considering surgical time in lower limb surgery, the noninferiority margin for the mean difference of the primary outcome was predetermined −10 min [ 19 , 20 ]. The independent t- test was employed to test the noninferiority of the primary outcome (the null hypothesis was that the mean difference in the two-dermatomal segment regression time was greater than −10 min.…”

Effect of Intraoperative Sedation with Dexmedetomidine Versus Propofol on Acute Postoperative Pain Following Major Foot Surgery under Popliteal Sciatic Nerve Block: A Randomized Controlled Trial

“…Dexmedetomidine is a potent α2-adrenoreceptor agonist with sedative and analgesic properties [6]. Intravenous (IV) dexmedetomidine as a sedative for surgery under regional anesthesia has been studied widely because it produces the unconsciousness similar to that of natural sleep without respiratory depression [7], and reduces postoperative pain and opioid consumption [8,9]. More recent studies assessed the effect of dexmedetomidine as an intraoperative sedative drug on the analgesic duration under spinal anesthesia [8,9], but the evidence of its efficacy on popliteal sciatic nerve block is still lacking.…”