Dexamethasone as a ropivacaine adjuvant for ultrasound-guided interscalene brachial plexus block: A randomized, double-blinded clinical trial.

STUDY OBJECTIVE

The purpose of this study was to evaluate the effect of intravenous or perineural dexamethasone added to ropivacaine on the duration of ultrasound-guided interscalene brachial plexus blocks (BPB).

DESIGN

Randomized clinical trial.

SETTING, PATIENTS AND INTERVENTIONS: Sixty ASA physical status I-II patients with elective shoulder arthroscopic surgeries under interscalene brachial plexus blocks were randomly allocated to receive 20ml of 0.75% ropivacaine with 1ml of isotonic saline (C group, n=20), 20ml of 0.75% ropivacaine with 1ml (4mg) of perineural dexamethasone (Dpn group, n=20), or 20ml of 0.75% ropivacaine with 1ml of isotonic saline and intravenous 4mg dexamethasone (IV) (Div group, n=20). A nerve stimulation technique with ultrasound was used in all patients.

MEASUREMENTS

The onset time and duration of sensory blocks were assessed. Secondary outcomes were pain scores (VAS) and postoperative vomiting and nausea (PONV).

MAIN RESULTS

The duration of the motor and sensory block was extended in group Dpn compared with group Div and group C (P<0.05). In addition, within 24h, group Dpn presented lower levels of VAS and lower incidence of PONV as compared with the other groups. Moreover, there was a significant reduction on onset time between group Dpn and the other groups.

CONCLUSIONS

Perineural 4mg dexamethasone was more effective than intravenous in extending the duration of ropivacaine in ultrasound-guided interscalene BPB. Moreover, Dpn has significant effects on onset time, PONV, and VAS.