Renes 2009.

Methods	RCT, parallel design
Participants	60 patients, ASA I ‐ III, scheduled for elbow, forearm, wrist and hand surgery under supraclavicular brachial plexus block without sedation Excluded: Patients refusing supraclavicular block, inability to obtain informed consent, hemidiaphragmatic dysfunction, coagulation disorders, neuropathy, pulmonary and cardiac disorders, BMI 35 kg/m² or higher, pregnancy, allergy to LA
Interventions	Ultrasound (n = 30) vs neurostimulation (n = 30) Supraclavicular brachial plexus block of ulnar, median, radial and musculocutaneous nerves with 20 ml 0.75% ropivacaine Ultrasound: 38 mm 6 ‐ 13 MHz broadband linear array US probe to identify brachial plexus in short‐axis view located lateral to the subclavian artery. In‐plane approach Nerve stimulation (HNS 11, B. Braun):pulse duration 0.1 msec, frequency 2 Hz. Endpoint: Flexion of both fingers and wrist or extension of fingers at a stimulation current between 0.20 and 0.50 mA
Outcomes	Supplementation rate (need for intraoperative intravenous fentanyl due to pain; or supplementation of local anaesthetic or GA) Adequacy of block (defined as "absent sensation in the sensory distribution of all ...nerves" Diaphragmatic movements assessed by ultrasonography for presence of hemidiaphragmatic paresis
Notes	For Supplementation rate we took data for intravenous fentanyl administration only. There were no participants requiring local anaesthetic or GA.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated sequence of random numbers
Allocation concealment (selection bias)	Unclear risk	Sealed envelopes. No further details
Blinding of participants and personnel (performance bias):adequacy of block, need for supplementation	High risk	Not possible to blind anaesthetist
Blinding of outcome assessment (detection bias): adequacy of block, supplementation of block	Unclear risk	No details of who assessed this and whether blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	No apparent losses after randomization
Selective reporting (reporting bias)	Unclear risk	Prepublished protocol not sought
Baseline characteristics	Low risk	Largely comparable
Funding sources	Low risk	None; department funding only
Operator expertise	Unclear risk	No details given of who gave anaesthetic and level of expertise