<qa>  What is the most commonly used adjunct to peripheral nerve blockade?Currently, the most commonly employed adjunct to peripheral nerve blockade is perineural dexamethasone. In general, at the doses used in regional anesthesia, dexamethasone has a minimal side effect profile. However, while it has been shown to increase duration of analgesia, there have been concerns regarding its neurotoxicity in animal studies. In addition, dexamethasone has the potential to cause hyperglycemia in patients with impaired glucose metabolism as well as perineal pain and pruritis when administered peripherally. 