Ibraheim 2008

Methods	RCT
Participants	Participants country: Saudi Arabia N = 30 ASA: I/II 8/7, 10/5 Morbidity obese: body‐mass index of greater than 35 Gender: male/female 9/6, 11/4 Age: 39± 4.50, 41.21± 5.07 years Exclusion: renal, hepatic or neurological dysfunction or use of benzodiazepines, anticonvulsants, alcohol, opioids or other psychotropic drugs Operation: gastric banding procedures Duration of anaesthesia: 136.6±113.7, 138.9±13.8 minutes
Interventions	1) Sevoflurane administration guided by BIS (BIS A‐2000 software 2.21, Aspect Medical Systems, Newton, and Mass), BIS value of 40‐60 during maintenance (BIS group), Cn = 15 2) Sevoflurane administration guided by signs of inadequate anaesthesia (increased blood pressure of greater than 20%, increased heart rate of greater than 90 beats per minutes and other somatic responses) (CS group), Cn = 15
Outcomes	Sevoflurane used during maintenance (ml/hr) Recovery times (min) ‐time to awakening (opening eyes on verbal command) ‐time to extubation ‐time to Aldrete score of 9
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information
Allocation concealment (selection bias)	Unclear risk	Insufficient information about the allocation concealment
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficiet information regarding withdrawal/dropouts
Selective reporting (reporting bias)	Low risk	All expected outcome reported
Other bias	Unclear risk	The unblinded anaesthesiologist could potentially lead to 'learning contamination bias'
Blinding of patients?	Low risk	All patients were anaesthetized
Blinding of anaesthesiologists?	High risk	"Group BIS: the anaesthesiologist had access the monitor.." This indicates no blinding of the anaesthesia care provider
Blinding of outcome assessors?	Low risk	"Blinded study personnel recorded the time ...." This is blinding of outcomes assessors