Brull 2009.

Methods	RCT, parallel design
Participants	106 ASA I ‐ III participants scheduled for elbow, forearm, wrist or hand surgery Excluded: age < 18 or > 70 yr, language barrier, contraindication(s) to regional anaesthesia, weight > 100 kg, pre‐existing neurological deficit in the distribution to be anaesthetized, local infection, coagulopathy, chest or shoulder deformities, severe respiratory disease, or clavicle fracture.
Interventions	Ultrasound (n = 53) versus nerve stimulation (n = 53) Intraclavicular brachial plexus block of radial, ulnar, median and musculocutaneous nerves. Total volume 30 ml local anaesthetic (2% lidocaine 15 mL and 0.5% bupivacaine 15 mL with epinephrine 1:200,000) Ultrasound: either linear probe 7 – 13 MHz (Philips/ATL HDI 5000) a 5 – 12 MHz (Philips HD11); endpoint ‐ visualization of lateral and posterior cord, LA injected incrementally to total volume of 30 ml. Nerve stimulation (Stimuplex): motor endpoints sought (elbow/ finger flexion, thumb opposition, wrist extension) at stimulating current of 0.3 ‐ 0.5 mA. 15 mL of LA injected incrementally at each position for a total of 30 mL. All participants given midazolam 2 – 4 mg iv as premedication. For nerve stimulation group, If 2 motor responses were not elicited within 20 min of needle insertion, procedure abandoned in favour of a different approach to brachial plexus blockade, and participant excluded from analysis.
Outcomes	Adequacy of block (defined as diminished sensation to pinprick at 20 min, in all 4 nerves) Supplementation rate (requirement for supplemental nerve block, skin infiltration or general anaesthesia). Data not reported in study Complications (cardiorespiratory arrest, seizures, pneumothorax, nerve injury, paraesthesia, vascular puncture, tachycardia) Time to perform block (duration of time from placement of the ultrasound probe on the skin to needle removal or palpation of anatomical landmarks to needle removal) Number of block attempts Participant discomfort during block placement
Notes	One of 4 experienced regional anaesthesiologists ‐ no further details of whether experience is balanced between techniques Supported by grant funding, equipment received from manufacturers for purpose of study ‐ no interests declared. Time to perform block reported as median (interquartile range) and therefore not possible to combine in this review
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomization table
Allocation concealment (selection bias)	Unclear risk	No details given
Blinding of participants and personnel (performance bias):Complications	High risk	Anaesthetist not blinded
Blinding of participants and personnel (performance bias): time outcomes	High risk	Anaesthetist not blinded
Blinding of participants and personnel (performance bias): Patient discomfort	High risk	Anaesthetist not blinded
Blinding of outcome assessment (detection bias): adequacy of block, supplementation of block	Low risk	Evaluated by blinded observer
Blinding of outcome assessment (detection bias): Complications	Low risk	Evaluated by blinded observer
Blinding of outcome assessment (detection bias): time outcomes	Low risk	Evaluated by blinded observer
Blinding of outcome assessment (detection bias): Patient discomfort	Low risk	Participants blinded with use of 'sham' equipment
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Small number of exclusions (5 participants) with clear reasons given. However, only 49% participants available for assessment of complications at postoperative day 7
Selective reporting (reporting bias)	Unclear risk	No data available for pain on injection. Also published protocol not sought
Baseline characteristics	Low risk	Largely comparable, although some differences in types of surgery between groups
Funding sources	High risk	Funding from grants, equipment supplied by named manufacturers. Unclear whether any bias has been introduced
Operator expertise	Unclear risk	Anaesthetists described as experienced but no detail of whether experience is equivalent for both techniques