Dubois 1999.

Methods	Randomization and treatment allocation method: not stated Blinding of outcome assessment: no Blinding of participants: no Study period: not stated
Participants	Number: 65 enrolled Inclusion criteria: children 2 to 10 years of age, ASA physical status I to II, scheduled for tonsillectomy, entered the study Exclusion criteria: not stated
Interventions	All groups received 0.3 mg/kg midazolam rectally Anaesthesia was induced by face mask and open circuit without carbon dioxide absorber according to Group 1: 2%, 4%, 6%, 7% sevoflurane in 100% O2 Group 2: 7% sevoflurane in 100% O2 Group 3: 7% sevoflurane in 50% N2O and 50% O2
Outcomes	Quality of mask acceptance Degree of airway obstruction during induction Quality of tracheal intubation Time to loss of eyelash reflex Time to obtain central pupils Time to intubation Adverse events (coughing, apnoea, laryngospasm, bronchospasm, secretions, vomiting, dysrhythmia, agitation and oxygen desaturation < 95%) End‐tidal gas concentration Systolic and diastolic arterial pressure, heart rate, oxygen saturation
Notes	Location: France Setting: operating room Source of funding: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Information insufficient to permit judgement
Allocation concealment (selection bias)	Unclear risk	Information insufficient to permit judgement
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Quote: "trainee was in charge of recording induction events and monitoring parameters"
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing data
Selective reporting (reporting bias)	Low risk	Study authors reported all planned outcomes