Impact of local administration of various doses of dexmedetomidine on ropivacaine‑induced lumbar plexus‑sciatic nerve block

Abstract

The present study aimed to investigate the impact of various doses of dexmedetomidine (DEX) on ropivacaine (ROP)-induced lumbar plexus-sciatic nerve block (LSB). A total of 80 patients who underwent ankle surgery under LSB were divided into group R (applied with 30 ml 5% ROP), Dex1 (30 ml 0.5% ROP + 1 µg/kg DEX), Dex2 (30 ml 0.5% ROP + 1.5 µg/kg DEX) and Dex3 (30 ml 0.5% ROP + 2 µg/kg DEX), with 20 cases in each group. The onset time and duration of sensory and motor block, mean arterial pressure (MAP), heart rate (HR), oxygen saturation, Ramsay score, serum vascular endothelial growth factor (VEGF) level and adverse reactions in the four groups were observed. Results demonstrated that the durations of sensory and motor block in group R were shorter than those in groups Dex1-3 (P<0.01), followed by the sequence of group Dex1<Dex2<Dex3 (P<0.05). MAP and HR in groups Dex1-3 at T2-T5 were significantly lower than those in group R (P<0.01), and HR in group Dex3 at T3 and T4 was significantly lower than that in groups Dex1 and Dex2 (P<0.05). Ramsay scores in groups Dex1-3 at T2-T4 were significantly higher than those in group R (P<0.05). Serum VEGF levels in groups Dex2 and Dex3 at T2-T5 were significantly higher than those in group R (P<0.01). The incidences of over-sedation, bradycardia and dry mouth in group Dex3 were notably higher than those in the other groups. In conclusion, 1.5 µg/kg DEX exhibits a superior effect in improving ROP-induced LSB.

Dexmedetomidine as an Adjuvant in Peripheral Nerve Block

“…Yu et al 65 added 1 µg/kg, 1.5 µg/kg, and 2 µg/kg of dexmedetomidine to 30 mL 0.5% ropivacaine (ROP) in 80 patients undergoing LSB lower ankle surgery. The results suggested that the peripheral nerve administration of dexmedetomidine (2 µg/kg) was consistent with ropivacaine, which can most significantly prolong the duration of sensory and motor block.…”

Impact of Bilateral Quadratus Lumborum Block Using Different Doses of Dexmedetomidine for Postoperative Analgesia in Laparoscopic Myomectomy

“…In Asia, Europe, and the United States, DEX has been frequently applied outside the ranges regulated by the Food and Drug Administration,23,24 and has been demonstrated in textbooks and multiple studies as an adjuvant. Suitable dosage of DEX varies among different kinds of peripheral nerve block.…”

“…Suitable dosage of DEX varies among different kinds of peripheral nerve block. Jian Yu et al 23 showed that 1.5 μg/kg DEX exhibited a superior effect in improving ropivacaine-induced lumbar plexus sciatic nerve block. Brummett et al 24 proposed 2 μg/kg as the clinical dose of perineural administration of DEX and used this dosage to calculated the concentration of DEX in their study in rats.…”

“…α2 adrenoceptor agonists, including dexmedetomidine, also have an inhibitory effect on Na+ channels in neurons, which may explain its enhanced effect on analgesia to some extent. 22 In Asia, Europe, and the United States, DEX has been frequently applied outside the ranges regulated by the Food and Drug Administration, 23,24 and has been demonstrated in textbooks and multiple studies as an adjuvant. Suitable dosage of DEX varies among different kinds of peripheral nerve block.…”

Impact of Bilateral Transmuscular Quadratus Lumborum Block Using Different Doses of Dexmedetomidine as an Adjuvant Combined with Ropivacaine for Postoperative Analgesia in Laparoscopic Myomectomy

“…Suitable dosage of dexmedetomidine varies among different kinds of peripheral nerve block. Jian Yu et al in 2018 [13] showed that 1.5 μ g/kg DEX exhibited a superior effect in improving ROP induced lumbar plexus sciatic nerve block. A study published in 2008 [14] recommended 2 μ g/kg as the clinical dose of perineural administration of dexmedetomidine.…”