Adjuvants to prolong regional anesthesia

For my single shot blocks, I’m always looking for ways to prolong my regional anesthetic effect. For awhile, Exparel was the most talked about drug to have a 72 hour blockade. We don’t have this medication available to us at the hospital. Therefore, it’s time to get creative and hit the literature to see what has worked for prolonging our blocks.

Prolonging blockade with adjuvants:

IOSR J of Dental and Medical Sci; Dec 2015. Comparative study of bupiv with dexamethasone and bupi with clonidine through single space PVB for post op analgesia in thoracic and abdominal surgeries.
- 0.125% Bupiv + clonidine (1mcg/kg) vs 0.125% bupiv + dexamethasone (4mg): greater duration of analgesia in the dexamethasone group.

Facilitatory effects of perineural dexmedetomidine on neuraxial and peripheral nerve block: a systematic review and meta-analysis. British Journal of Anaesthesia 110 (6): 915–25 (2013).
- Sensory block duration was prolonged by 150 min [95% confidence interval (CI): 96, 205, P,0.00001] with intrathecal dexmedetomidine. Perineural dexmedetomidine used in brachial plexus (BP) block may prolong the mean duration of sensory block by 284 min (95% CI: 1, 566, P¼0.05), but this difference did not reach statistical significance. Motor block duration and time to first analgesic request were prolonged for both intrathecal and BP block. Dexmedetomidine produced reversible bradycardia in 7% of BP block patients, but no effect on the incidence of hypotension. No patients experienced respiratory depression.
- Considerable differences existed in the doses of perineural dexmedetomidine; doses varied between 3, 5, 10, or 15 mcg for the intrathecal route, and 30, 100, 0.75, 1 mcg/kg for the peripheral route.

Investigating the Efficacy of Dexmedetomidine as an Adjuvant to Local Anesthesia in Brachial Plexus Block: A Systematic Review and Meta-Analysis of 18 Randomized Controlled Trials. Regional Anesthesia and Pain Medicine: March/April 2017 – Volume 42 – Issue 2 – p 184–196.

Effective Dose of Intravenous Dexmedetomidine to Prolong the Analgesic Duration of Interscalene Brachial Plexus Block: A Single-Center, Prospective, Double-Blind, Randomized Controlled Trial. Regional Anesthesia and Pain Medicine: July 2018 – Volume 43 – Issue 5 – p 488–495.
- Intravenous DEX at a dose of 2.0 μg/kg significantly increased the duration of ISBPB analgesia without prolonging motor blockade and reduced the cumulative opioid consumption at the first 24 hours in patients undergoing arthroscopic shoulder surgery.

Dexmedetomidine prolongs the effect of bupivacaine in supraclavicular brachial plexus block. J Anaesthesiol Clin Pharmacol. 2014 Jan-Mar; 30(1): 36–40.
- 30 ml of 0.325% bupivacaine + 1 ml (100 μg) dexmedetomidine were given for supraclavicular brachial plexus block using the peripheral nerve stimulator.

Effects of perineural administration of dexmedetomidine in combination with bupivacaine in a femoral-sciatic nerve block. Saudi J Anaesth. 2016 Jan-Mar; 10(1): 18–24.
- Below knee surgery under combined femoral-sciatic nerve block were randomly allocated into two groups to have their block performed using bupivacaine 0.5% alone (group B) or bupivacaine 0.5% combined with 100 μg bupivacaine-dexmedetomidine

IV and Perineural Dexmedetomidine Similarly Prolong the Duration of Analgesia after Interscalene Brachial Plexus Block: A Randomized, Three-arm, Triple-masked, Placebo-controlled Trial. Anesthesiology 3 2016, Vol.124, 683-695.
- Randomized to receive ISB using 15 ml ropivacaine, 0.5%, with 0.5 μg/kg dexmedetomidine administered perineurally (Dex_P group), intravenously (Dex_IV group), or none (control group). Dex_IV was noninferior to Dex_P for these outcomes. Both dexmedetomidine routes reduced the pain and opioid consumption up to 8 h postoperatively and did not prolong the duration of motor blockade.