Coll‐Vinent 2003.

Methods	Single‐centre parallel‐group randomized controlled trial conducted in Spain
Participants	32 consecutive adults undergoing cardioversion for supraventricular arrhythmia in an emergency department
Interventions	Randomized to 1 of 4 treatment arms (all intravenous administration): 1) 0.2 mg/kg midazolam 2) 0.2 mg/kg etomidate 3) 1.5 mg/kg propofol 4) 0.2 mg/kg midazolam and flumazenil 0.5 mg bolus followed by 0.5 mg infusion for 1 hour If induction was not achieved within 3 ‐ 5 minutes, supplementary doses of etomidate (0.05 mg/kg), midazolam (0.05 mg/kg) or propofol (0.5 mg/kg) were injected at 1‐minute intervals until the desired effect was obtained
Outcomes	Measured during the procedure: Level of sedation using a sedation assessment scale (Ramsay scale) Vital signs (systolic blood pressure after sedation) Vital signs (desaturation < 90%) Duration of sedation Onset of sedation Measured after the procedure: Offset time of sedation
Notes	Only median values reported for continuous outcomes (skewed distributions because of small sample size). We did not include the midazolam and flumazenil group in our review because combinations of medications with midazolam were excluded. The authors declared that no outside funding or support was received for the study. No other conflicts of interest were reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random‐number table
Allocation concealment (selection bias)	Low risk	Sealed envelopes
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not blinded
Blinding of outcome assessment (detection bias) All outcomes	High risk	Not blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	No withdrawals
Selective reporting (reporting bias)	Unclear risk	No clear evidence that measured outcomes were not reported (trial protocols were not sought for confirmation)
Other bias	Low risk	None expected