[Intravenous dexamethasone enhances efficacy of brachial plexus block via the costoclavicular space: a randomized,...

To investigate the effect of intravenous 8 mg dexamethasone injection on the efficacy of ultrasound-guided brachial plexus block (BPB) with 20 mL 0.375% ropivacaine via the costoclavicular space (CCS).

Eighty-four patients (18-65 years, ASA I-II, and BMI 18-25 kg/m²) undergoing elective surgery below the elbow were randomized into two groups to receive ultrasound-guided BPB with 20 mL 0.375% ropivacaine via the CCS combined with intravenous injection of 8 mg (4 mL) dexamethasone (trial group) or 4 mL normal saline (control group). The mean arterial pressure (MAP) and heart rate (HR) were measured before block, at the end of block, and at the start of surgery, and the type of surgery, duration of surgery, and block onset time (T1) were recorded. After the operation, the patients were followed up for durations of sensory (T2) and motor (T3) block, patient's satisfaction with anesthesia, incidences of nausea and vomiting within 24 h, and incidences of nerve block-related adverse effects within one week.

No significant difference in block onset time was found between the two groups (P>0.05). The patients in the trial group exhibited significantly prolonged T2 and T3 (P<0.001) with higher anesthesia satisfaction (P<0.05). No significant differences were observed in postoperative adverse events between the two groups (P>0.05).

Intravenous 8 mg dexamethasone, which does not affect block onset time of BPB via the CCS, significantly prolongs the sensory and motor block durations and improves anesthesia satisfaction without significantly increasing the incidences of postoperative adverse events.