Background: Mixing of various adjuvants has been tried with local anesthetics in an attempt to prolong anesthesia from peripheral nerve blocks but have met with inconclusive success. More recent studies indicate that 8 mg dexamethasone added to perineural local anesthetic injections augment the duration of peripheral nerve block analgesia.
Aims: Evaluating the hypothesis that adding dexamethasone to ropivacaine significantly prolongs the duration of analgesia in supraclavicular brachial plexus block compared with ropivacaine alone.
Patients and methods: It was a randomized, prospective, and double-blind clinical trial. Eighty patients of ASA I and II of either sex, aged 16-60 years, undergoing elective upper limb surgeries were equally divided into two groups and given supraclavicular nerve block. Group R patients (n = 40) received 30 ml of 0.5% ropivacaine with distilled water (2 ml)-control group whereas Group D patients (n = 40) received 30 ml of 0.5% ropivacaine with 8 mg dexamethasone (2 ml)-study group. The primary outcome was measured as duration of analgesia that was defined as the interval between the onset of sensory block and the first request for analgesia by the patient. The secondary outcome included maximum visual analogue scale (VAS), total analgesia consumption, surgeon satisfaction, and side effects.
Results: Group R patients required first rescue analgesia earlier (557 ± 58.99 min) than those of Group D patients (1179.4 ± 108.60 min), which was found statistically significant in Group D (P < 0.000). The total dose of rescue analgesia was higher in Group R as compared to Group D, which was statistically significant (P < 0.00).
Conclusion: Addition of dexamethasone (8 mg) to ropivacaine in supraclavicular brachial plexus approach significantly and safely prolongs motor blockade and postoperative analgesia (sensory) that lasted much longer than that produced by local anesthetic alone.
Keywords: Adjuvants; analgesia; dexamethasone; local anesthetics; peripheral nerve blocks.