Chalifoux 2017.

Methods	Parallel group RCT.
Participants	In Canada, 75 participants undergoing arthroscopic shoulder surgery with interscalene brachial plexus block. Exclusion criteria included participants with contraindications to interscalene block (coagulopathies, severe bronchopulmonary disease, contralateral diaphragmatic paralysis, prior contralateral pneumonectomy, preexisting neuropathy involving the surgical limb), preference for general anaesthesia, allergy or intolerance to one or more medications of the study protocol (dexamethasone, acetaminophen, morphine, or hydromorphone), chronic pain syndrome, chronic opioid use, chronic systemic corticosteroid use, weight\50 kg and pregnancy.
Interventions	Block All participants received ultrasound and nerve stimulator‐guide interscalene brachial plexus block with ropivacaine 0.5% 20 ml. Dexamethasone/placebo Participants in the dexamethasone group received dexamethasone 10 mg diluted to a final volume with normal saline of 20 ml intravenously. Participants in the placebo group received 20 ml normal saline intravenously. Intraoperative anaesthesia/analgesia All participants received midazolam 1‐2 mg and/or fentanyl 25‐50 ug before block administration. Participants could receive an additional midazolam 1‐2 mg intravenously every 30 minutes and/or propofol 25‐100 ug/kg/min. Postoperative analgesia Acetaminopen 650 mg orally every six hours. Hydormorphone 1‐2 mg orally or morphine 5‐10 mg orally every 4 hours for pain score greater than or equal to 4.
Outcomes	Outcomes of interest for the review Duration of sensory block defined as the time from the onset of block to the first analgesic request. Intensity of postoperative pain at 12, 24 and 48 hours. Cummulative opioid consumption at 12, 24 and 48 hours. Participant satisfaction. Adverse events including pruritus on administration of study drug and residual motor block at 24 and 48 hours postoperatively. Other outcomes Intensity of postoperative pain at 36 hours. Cummulative opioid consumption at 36 hours. Differences in variation of blood glucose concentration.
Notes	This was a three‐arm study comparing dexamethasone 4 mg, dexamethasone 10 mg and placebo. In order to avoid unit of analysis issues we decided to include the dexamethasone 10 mg group and exclude the 4 mg group because high‐dose dexamethasone is used most often in clinical practice. Funding: funded by the Department of Anesthesiology, Hôpital Mainsonneve, Montréal, Quebec. 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)	Low risk	Allocation was concealed in sealed envelopes.
Blinding of participants (detection bias)	Low risk	Participants were blinded.
Blinding of personnel (detection bias)	Low risk	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	One participant from the dexamethasone group and three participants from the placebo group were excluded.
Selective reporting (reporting bias)	Low risk	No protocol available. All outcomes reported as described in the methods section.
Other bias	Low risk	Appears to be free of any other bias.