Kerforne 2012.

Study characteristics
Methods	Randomised, open‐label trial
Participants	Setting: ICU Number of participants: 60 (USG 30, LM 30) Age, mean (SD) years: USG 61 (17), LM 56 (15) Difficulty: difficult (an operator could not see and palpate the targeted vein) Sites of peripheral veins: upper extremity
Interventions	Technique LM vs USG: Machine: Vivid e (General Electric) with a 10 MHz probe Axis: not specified Guidance: dynamic Operator Profession: nurse Number of operators: not specified Experience of USG before the study: not specified Length of experience with USG before the study: not specified A training programme of USG for the study: not specified Number of clinical cases with USG required or experienced before the study intervention started: not specified Needle Length: not specified Gauge: not specified
Outcomes	First‐pass success of cannulation, overall successful of cannulation, procedure time for overall cannulation Definition of successful cannulation: not specified Definition of start and end of time measurement Start: an operator put on sterile gloves End: a return of blood in tubing and the possibility of infusing a few millilitres of saline without pain or extravasation
Funding	University Hospital of Poitiers
Declarations of interest	None declared
Notes	Data for first‐pass success of cannulation were unpublished and obtained through communication with an author (TK). We attempted to contact the authors to obtain additional information for the risk of bias (ROB) assessment but did not receive a response.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No description of randomisation process
Allocation concealment (selection bias)	Unclear risk	No description of allocation concealment
Blinding (performance bias and detection bias) First‐pass success of cannulation	High risk	Blinding of participants and operators is impossible due to the nature of the intervention. Operators assessed the outcome themselves (this was not stated in the article, but obtained through communication with an author (TK))
Blinding (performance bias and detection bias) Overall‐success of cannulation	High risk	Blinding of participants and operators is impossible due to the nature of the intervention. Operators assessed the outcome themselves (this was not stated in the article, but obtained through communication with an author (TK))
Blinding (performance bias and detection bias) Procedure time for overall cannulation	Low risk	Although blinding of participants and operators is impossible due to the nature of the intervention, a third‐person assessed the outcome (this was not stated in the article, but obtained through communication with an author (TK))
Incomplete outcome data (attrition bias) First‐pass success of cannulation	Low risk	The outcome was available for all participants
Incomplete outcome data (attrition bias) Overall success of cannulation	Low risk	The outcome was available for all participants
Incomplete outcome data (attrition bias) Procedure time for overall cannulation	High risk	The outcome was evaluated only for participants with successful cannulation
Selective reporting (reporting bias)	Unclear risk	No study register or protocol was available
Other bias	Low risk	No concerns about other sources of bias
Overall risk First‐pass success of cannulation	High risk	At least one domain was at high risk
Overall risk Overall success of cannulation	High risk	At least one domain was at high risk
Overall risk Procedure time for overall cannulation	High risk	At least one domain was at high risk