Spinal anesthesia for lengthy lower limb orthopedic surgeries: dexmedetomidine plus fentanyl versus dexmedetomidine

Abstract

Background: Spinal anesthesia is efficient but of limited duration. Intrathecal dexmedetomidine prolongs the sensory and motor blockade of bupivacaine. Dexmedetomidine-opioids combination displayed a clinically controversial interaction. Our proposal is that fentanyl may augment the block characteristics of dexmedetomidine using proper doses. Patient and methods: This is a randomized double-blinded study. The included patients were scheduled for orthopedic procedures expected to extend more than 4 h. Patients were allocated into two groups each of 23. Group D received intrathecal bupivacaine 20 mg 0.5% + dexmedetomidine 10 μg. Group DF received bupivacaine 20 mg 0.5% + dexmedetomidine 10 μg + fentanyl 25 μg. The spinal block characteristics and adverse effects were determined. Data were compared by t test, Mann-Whitney, and chi-square tests as appropriate. Results: There was no significant difference between the two groups as regards spinal block and hemodynamic characteristics. The addition of fentanyl provided earlier time to T10 sensory block, lower midazolam and ephedrine utilization, but occasional mild itching. Postoperatively, the time to the first analgesic request, morphine consumption, and patient's satisfaction were not different. Conclusion: The addition of fentanyl does not prolong the sensory and motor block characteristics of dexmedetomidine. In favor of dexmedetomidine-fentanyl combination was the less hypotension and less sedative requirement.

Dexmedetomidine vs. fentanyl as adjuvants to hyperbaric bupivacaine for unilateral spinal anesthesia in lower limb orthopedic surgeries: a randomized trial

“…6 The hypnotic effect of DEX is like normal sleep, it is mediated by the triggering of neurotransmitters that decrease histamine due to inhibition of the descending noradrenergic inhibitory pathway. 8 Sedation score in our study were comparable in both groups with no significant difference between the two groups.…”

“…Open access attribution (CC BY-NC 4.0) Mazy et al found that 48% of patients who received intrathecal DEX and 75% of those who received DEX and fentanyl had sedation scores > 2 and that was statistically insignificant. 8 Regarding the side effects, no patient had had respiratory depression, 1 patient in Group D and 2 in Group F had vomiting, 1 (3.7%) patient in Group D compared to 3 (11.1%) in Group F had shivering, but the difference was statistically insignificant; no patient in Group D had pruritus compared to 2 in Group F, the difference being statistically significant. These results are supported by the results of Gupta et al 5…”

“…7 Mazy et al, compared DEX plus fentanyl versus DEX as adjuvants to bupivacaine in patients undergoing orthopedic procedures expected to extend more than 4 h, found that the time to the first request for analgesia and the total morphine consumption was not different between the two groups, VAS scores also showed no significant differences in their study. 8 Yektaş and Belli, who compared the effects of 2 μg and 4 μg of DEX in combination with intrathecal hyperbaric bupivacaine on spinal anesthesia in patients undergoing elective inguinal hernia repair, found that the mean time to onset of pain was longer in the group who received 4 μg than the other group. 9 Also according to Rai and Bhutia, adding 5 μg DEX as an additive to spinal anesthesia in orthopedic patients undergoing lower limb surgeries was superior to 3 μg in prolonging time to rescue analgesia.…”

<p>Selective Spinal Anesthesia in a Patient with Low Ejection Fraction Who Underwent Emergent Below-Knee Amputation in a Resource-Constrained Setting</p>

“…10 There is compelling evidence that adding adjuvants, such as opioids and α-2 agonists to a reduced dose of an intrathecal local anesthetics (LA) can decrease LA related adverse effects and prolong postoperative analgesia without compromising intraoperative anesthesia. [11][12][13] Having these experiences in mind, we conducted a modified spinal block using a mixture of low dose heavy bupivacaine (7.5 mg), dexmedetomidine (4 µg) and fentanyl (25 µg).…”

“…The addition of dexmedetomidine plus fentanyl to bupivacaine intrathecally not only reduced the dose of an intrathecal LA requirement but also enhanced the duration of postoperative analgesia, and was not associated with hemodynamic instability. 11,13 On the other hand, dexmedetomidine added to hyperbaric bupivacaine intrathecally has a dosedependent (5 µg versus 10 µg) favorable effect on the onset and regression of sensory and motor block. 17 Spinal anesthesia-induced hypotension is one of the commonest immediate complications after the block due to arterial and venous vasodilatation resulting from the sympathetic block along with a paradoxical activation of cardio-inhibitory receptors.…”