SLR - August 2018 - Christopher Sullivan

Perineural Versus Systemic Dexamethasone in Front-Foot Surgery Under Ankle Block: A Randomized Double-Blind Study

Reference: Philippe Marty; Olivier Rontes; Clément Chassery; Corine Vuillaume; Bertrand Basset; Mehdi Merouani; Constance Marquis; Benoit Bataille; Martine Chaubard; Marie Claude Mailles; Fabrice Ferré; Alain Delbos. Perineural Versus Systemic Dexamethasone in Front-Foot Surgery Under Ankle Block: A Randomized Double-Blind Study. Reg Anesth Pain Med 2018;43: 00–00

Scientific Literature Review

Reviewed By: Christopher Sullivan, DPM
Residency Program: Beth Israel Deaconess Medical Center, Boston, MA

Podiatric Relevance: Postoperative pain management represents a continual challenge in podiatric surgery. Compared with oral analgesia, regional anesthesia is associated with better pain relief, less opioid consumption and less nausea and vomiting. While the exact mechanism is not well understood, it is known that the administration of dexamethasone prolongs the effect of local anesthetics. Therefore, it may be in the interest of the podiatric surgeon, as well as the patient, to consider the use of dexamethasone as an adjunct therapy in preoperative regional anesthesia.  

Methods: A total of 100 patients undergoing metatarsal osteotomy (distal or proximal) with an ankle block were randomized into two groups: 30 mL ropivacaine 0.375 percent + perineural dexamethasone 4 mg (1 mL) + 2.5 mL of systemic saline solution (n=50) and 30 mL ropivacaine 0.375 percent + 1 mL of perineural saline solution + intravenous dexamethasone 10 mg (2.5 mL) (n=50). The primary end point was the duration of analgesia defined as the time between the performance of the ankle block and the first administration of rescue analgesia with tramadol.

Results: Time period to first rescue analgesia with tramadol was similar in the systemic dexamethasone group and the perineural dexamethasone group. Duration of analgesia was 23.2 hours in the systemic group and 19.0 hours in the perineural group. Average consumption of tramadol during the first 48 hours was 0 mg (range: 0–150 mg) in the systemic group versus 0 mg (range: 0–250 mg) in the perineural group. Maximal pain reported during the first 48 hours was equivalent in both groups (VRS=2, range 1–5). Four (8 percent) and 12 (24 percent) patients reported nausea or vomiting in the systemic group and the perineural group, respectively.

Conclusions: The authors conclude that when combined with a properly performed ankle block, both perineural and systemic routes of dexamethasone provide similar postoperative pain control with minimal consumption of tramadol. Furthermore, the authors note that the use of systemic dexamethasone carries the added benefit of decreasing the incidence of postoperative nausea and vomiting.  While this study was not designed to compare pain relief from dexamethasone plus ankle block with ankle block alone, it has been well established in the anesthesia literature that dexamethasone increases the duration of action of local anesthetics. Unless otherwise contraindicated, podiatric surgeons should consider advocating for the use of dexamethasone, either systemic or perineural, in addition to ropivacaine-based ankle blocks in obtaining analgesia following forefoot procedures. 

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