Effective Dose of Intravenous Dexmedetomidine to Prolong the Analgesic Duration of Interscalene Brachial Plexus Block

Abstract

This study was registered at the Clinical Trial Registry of Korea, identifier KCT0002119.

Superior Trunk Block Provides Noninferior Analgesia Compared with Interscalene Brachial Plexus Block in Arthroscopic Shoulder Surgery

“…For this reason, it is standard practice in our institution to use 15 ml of 0.5% ropivacaine for interscalene brachial plexus blockade in patients undergoing arthroscopic shoulder surgery. 1,2 This is also consistent with the reported practice in other centers. 26 We believe the significance and generalizability of our findings are strengthened by the use of a pragmatic local anesthetic dose in both treatment groups.…”

“…The interscalene block was performed using the posterior in-plane extraplexus approach. 1 Briefly, the block needle was advanced in-plane to the ultrasound beam at the level of the cricoid cartilage in a lateral-to-medial direction through the middle scalene muscle. The dorsal scapular nerve and long thoracic nerve were identified within the middle scalene muscle and avoided, using a combination of ultrasonographic visualization and neurostimulation with an initial current of 2.0 mA, pulse width of 100 ms, and a frequency of 2 Hz.…”

“…T he conventional ultrasound-guided interscalene brachial plexus block involves injection directly around the C5 and C6 nerve roots. Although it provides highly effective postoperative analgesia after arthroscopic shoulder surgery, 1,2 it almost always results in hemidiaphragmatic paresis. 3,4 Other concerns include the risk of intraneural injection into the relatively unprotected roots 5,6 and injury to the dorsal scapular nerve or long thoracic nerve.…”

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

“…Recently, intraoperative sedation with IV dexmedetomidine has been reported to demonstrate significant reduction in the postoperative opioid consumption and prolongation of postoperative analgesia after both spinal anesthesia [9] and peripheral nerve blocks [13,14]. The exact underlying mechanism of action of IV dexmedetomidine is still not fully understood, but more recent data implicated varied pathways for sedation and analgesia [15].…”

“…In addition, pharmacokinetics and pharmacodynamics studies have suggested that, compared with perineural injection, an adequate or a relatively high dose of IV dexmedetomidine is required to provide clinical analgesic effects [6,19,20]. Previous studies have shown that the clinical analgesic effects of IV dexmedetomidine were not evident below certain cut-off values [14]; in particular, a comparative study on analgesic effects showed that dexmedetomidine showed less analgesic effect up to plasma concentrations of 2.4 ng/ml than remifentanil, and this can be extrapolated to the IV dexmedetomidine dose of 1.25 µg/kg [19,20]. In agreement therewith, in the present study, IV dexmedetomidine was administered at the average dose of 1.66 µg/kg during surgery, which is higher than the cut-off values suggested in previous studies; in part, this might be due to the significantly prolonged analgesia as marked by a longer time to first rescue analgesic request and a subsequent decrease in the postoperative opioid consumption in the dexmedetomidine group in comparison with the propofol group.…”