Kim 2012.

Methods	Parallel group RTC.
Participants	In Korea, 40 ASA I‐II participants undergoing arthroscopic shoulder surgery with interscalene brachial plexus block were included. Participants with diabetes, pregnancy, coagulation disorders, sensitivity to local anaesthetic, severe chronic pulmonary disease, neurological deficiencies, neuropathy, infection at the surgical site, drug or alcohol dependency or history or chronic pain were excluded.
Interventions	Block All participants received ultrasound‐guided interscalene block with levobupivacaine 0.5% 10 ml. Dexamethasone/placebo Dexamethasone group: dexamethasone 5 mg perineurally. Placebo group: normal saline 2 ml perineurally. Intraoperative anaesthesia/analgesia Midazolam IV 1‐3 mg and fentanyl IV 25‐50 micrograms was administered before block was performed. After block was performed, glycopyrrolate IV 0.2 mg, pentothal sodium IV 4 mg/kg, fentanyl 1‐2 micrograms/kg and rocuronium IV 0.6 mg/kg was administered. Postoperative analgesia Ketorolac IV or opioid IM was administered when the participant reported VAS more than 4 or on participant request.
Outcomes	Intensity of postoperative pain measured on a 11‐point VAS assessed 12, 24 and 48 hours. Incidence of adverse events including nausea, vomiting, respiratory difficulties and neurological disabilities.
Notes	This was a three‐arm study of 60 participants. In group III epinephrine 1:400 000 was given perineurally, however, the 20 participants of this arm are not included in this review as this is not an intervention of interest. Funding: no information provided. Conflicts of interest: no information provided.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No indication of how the random sequence was generated.
Allocation concealment (selection bias)	Unclear risk	No indication of how the treatment allocation was concealed.
Blinding of participants (detection bias)	Unclear risk	No indication of whether participants were blinded.
Blinding of personnel (detection bias)	Unclear risk	No indication of whether personnel were 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)	High risk	The authors state analgesic consumption was not significantly different, however the results are not presented. In the abstract, the authors state they would assess sleep quality and satisfaction, however the results are not reported.
Other bias	Low risk	Appears to be free of any other bias.