Broch Porcar 1999.

Methods	RCT, parallel design
Participants	39 participants Elective procedure for drug‐resistant supraventricular tachyarrhythmia, atrial fibrillation, atrial flutter. 68% with heart disease ASA status not given. NYHA class I‐III (some imbalances, see 'Risk of bias' table below) ICU, hospital setting, Spain
Interventions	Propofol (1 mg/kg over 1 minute) Etomidate (0.2 mg/kg over 1 minute) Midazolam (0.05 mg/kg over 1 minute) For all 3 drugs, 50% of total quantity given initially, then boluses of 25% thereafter until patient was sedated. If more than calculated dose was necessary, a further 25% was given at 60‐second intervals Aim: for patient to be sedated to Ramsey Sedation Scale level 4
Outcomes	Hypotension Unintended apneic episodes Patient awareness/recall Success of cardioversion Myoclonus Time to loss of consciousness Time to awakening SpO² < 90%
Results	Propofol vs Etomidate vs Midazolam Hypotension (mean % drop in arterial systolic pressure (SD)): 24 (8) vs 0.3 (8) vs 14 (8) Apnoea: 1/13 vs 0/13 vs 1/12 Recall: data presented as total amnesia: 9/13 vs 12/13 vs 12/12 ‐ therefore reversed for this outcome to 4/13 vs 1/13 vs 0/12 Myoclonus: 0/13 vs 5/13 vs 0/12 Success of cardioversion: 9/13 vs 9/13 vs 9/12
Notes	Anaesthetic given by same nurse for all participants
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomized but no details
Allocation concealment (selection bias)	Unclear risk	No details
Blinding of participants and personnel (performance bias) Major adverse events	High risk	Assume nurse giving anaesthetic drugs was not blinded
Blinding of participants and personnel (performance bias) Patient reported outcomes (recall/satisfaction)	High risk	Assume nurse giving anaesthetic drugs was not blinded
Blinding of participants and personnel (performance bias) Success of cardioversion	High risk	No details. Assume all personnel were not blinded.
Blinding of participants and personnel (performance bias) Minor adverse events	High risk	Assume nurse giving anaesthetic drugs was not blinded
Blinding of participants and personnel (performance bias) Time to induction etc/need for resedation.	High risk	Assume nurse giving anaesthetic drugs was not blinded
Blinding of outcome assessment (detection bias) Major adverse event	Unclear risk	No details as to who assessed outcomes and whether they were blinded
Blinding of outcome assessment (detection bias) Patient reported outcomes (recall/satisfaction)	Unclear risk	No details as to who assessed outcomes and whether they were blinded
Blinding of outcome assessment (detection bias) Success of cardioversion	Unclear risk	No details as to who assessed outcomes and whether they were blinded
Blinding of outcome assessment (detection bias) Minor adverse events	Unclear risk	No details as to who assessed outcomes and whether they were blinded
Blinding of outcome assessment (detection bias) Time to induction etc./need for resedation	Unclear risk	No details as to who assessed outcomes and whether they were blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	No losses
Selective reporting (reporting bias)	Unclear risk	Prepublished protocol not sought
Other bias	High risk	Baseline imbalance: imbalance between groups of participants with NYHA class I (propofol 7.7%, etomidate 45.5%, midazolam 27.3%) Anaesthetists: All anaesthetics were given by 1 nurse External funding: no apparent funding/conflicts of interest