Woo 2015.

Methods	Parallel group RCT.
Participants	In Korea 36 ASA 1 to 2 participants aged 20 to 70 years undergoing arthroscopic shoulder surgery with interscalene brachial plexus block were included. Participants with coagulopathy, infection at block site, neurological deficit in the surgical limb, severe lung disease, contralateral diaphragmatic paralysis, systemic glucocorticoid use, chronic opioid use, peptic ulcer disease, uncontrolled diabetes mellitus or allergy to ropivacaine were excluded.
Interventions	Block All participants underwent interscalene brachial plexus block with ropivacaine 0.75% using nerve stimulator guidance. Dexamethasone/placebo Dexamethsaone group: dexamethasone 7.5 mg perineurally. Placebo group: normal saline perineurally. Intraoperative anaesthesia/analgesia Thiopentone 4 mg/kg. Fentanyl one to two micrograms/kg. Rocuronium 0.6 mg/kg. Sevoflurane in 50% air/oxygen mixture 1.0 to 1.5 minimum alveolar concentration. Postoperative analgesia Tramadol 100 mg up to 3 times a day when pain was at least three on Numerical Rating Scale or patient request. Ketorolac 30 mg up to 90 mg a day for insufficient analgesia.
Outcomes	Outcomes of interest for the review Duration of sensory block defined as the time the block was performed to the time of first analgesic request. Incidence of arm weakness and adverse events for the first 48 hours after surgery. Pain scores at 12, 24 and 48 hours after surgery. Other outcomes Number of participants not requiring analgesia. Analgesia consumption. Pain scores at 6 hours after surgery.
Notes	This was a three‐arm study comparing three doses of dexamethasone (2.5 mg, 5 mg and 7.5 mg) and placebo. In order to avoid unit of analysis issues we chose to include the dexamethasone 7.5 mg arm since this is the dose used most often in practice and to exclude the other arms. Funding: none. Conflicts of interest: none.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random sequence was computer‐generated.
Allocation concealment (selection bias)	Unclear risk	No indication how group allocation was concealed.
Blinding of participants (detection bias)	Low risk	Participants were blinded.
Blinding of personnel (detection bias)	Low risk	Personnel was blinded.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	OUtcome assessors were blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing outcome data.
Selective reporting (reporting bias)	Low risk	Protocol was registered with the Clinical Trial Registry of Korea. All outcomes reported as stated in the protocol.
Other bias	Low risk	Appears to be free of any other bias.