Orko 1976a.

Methods	RCT, parallel design
Participants	150 adult participants Elective procedure. No details of participants' diagnoses ASA status not given Hospital, Finland
Interventions	Diazepam given over period of 1 minute until speech sluggish and ptosis obvious (dose not given) Thiopentone in 2.5% solution injected over 1 minute (dose not given) Propanidid All groups given atropine (0.01 mg/kg given iv 2 minutes) before anaesthesia Aim: "when patient did not respond to questions, the level of anaesthesia was considered adequate"
Outcomes	Unintended apneic episodes Other arrhythmia Patient awareness/recall Success of cardioversion PONV Myoclonus Number of shocks
Results	Diazepam vs Thiopentone Apnoea: 2/50 vs 25/50 (P value < 0.001) Recall: 15/41 vs 1/40 (P value < 0.001) PONV: 0/50 vs 0/50 Myoclonus (defined as excitatory side effects, such as muscular tension or involuntary movements): 0/50 vs 4/50 Successful cardioversion: 42/50 vs 36/50 Mean number of shocks: 1.9 vs 2.1
Notes	No effect estimates provided with data Propanidid is no longer in use; therefore data were not taken from this group
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomized but no details given
Allocation concealment (selection bias)	Unclear risk	No details
Blinding of participants and personnel (performance bias) Major adverse events	High risk	Assume anaesthetist was aware of group allocation
Blinding of participants and personnel (performance bias) Patient reported outcomes (recall/satisfaction)	High risk	No details of blinding given. Assume anaesthetist was not blinded
Blinding of participants and personnel (performance bias) Success of cardioversion	High risk	No details of blinding given. Old study and assume cardiologist/surgeon was not blinded
Blinding of participants and personnel (performance bias) Minor adverse events	High risk	No details of blinding given. Assume anaesthetist was not blinded
Blinding of participants and personnel (performance bias) Time to induction etc/need for resedation.	High risk	No details of blinding given. Assume anaesthetist was not blinded
Blinding of outcome assessment (detection bias) Major adverse event	Unclear risk	No details given as to who recorded outcome data, although arrhythmias were analysed by someone unaware of group allocation
Blinding of outcome assessment (detection bias) Patient reported outcomes (recall/satisfaction)	Unclear risk	No details of whether participant was blinded
Blinding of outcome assessment (detection bias) Success of cardioversion	Unclear risk	No details given as to who recorded outcome data, although arrhythmias were analysed by someone unaware of group allocation
Blinding of outcome assessment (detection bias) Minor adverse events	Unclear risk	No details given as to who recorded outcome data, although arrhythmias were analysed by someone unaware of group allocation
Blinding of outcome assessment (detection bias) Time to induction etc./need for resedation	Unclear risk	No details given as to who recorded outcome data, although arrhythmias were analysed by someone unaware of group allocation
Incomplete outcome data (attrition bias) All outcomes	Low risk	No losses reported
Selective reporting (reporting bias)	Unclear risk	All outcomes appear to be reported from methods section Prepublished protocol not sought
Other bias	Low risk	Baseline characteristics comparable