Song 1997

Methods	RCT
Participants	Country: USA N = 60 (30 sevoflurane, 30 desflurane) Sex: female Exclusion: neurologic disease, CVS or metabolic diseases, impaired renal or hepatic function, BW > 100% above the ideal or history of alcohol or drug abuse Operation: laparoscopic tubal ligation Desflurane subgroup (treatment, control) ‐ASA: I/II; 10/5, 11/4 ‐Age: 28±4, 27±6 ‐Duration of anaesthesia:76±20;78±22 min Sevoflurane subgroup (treatment, control) ‐ASA: I/II; 11/4, 10/5 ‐Age: 26±6, 26±7 ‐Duration of anaesthesia: 74±21, 75±21 min
Interventions	Desflurane guided by BIS (Rev 3.12U; Model A ‐1050, Aspect Medical Systems, Natick, MA) at value of 60 Desflurane using standard clinical guide Sevoflurane guided by BIS BIS (Rev3.12U; Model A ‐1050, Aspect Medical Systems, Natick, MA) at value of 60 Sevoflurane using standard clinical guide
Outcomes	‐End tidal concentration (%) ‐Exposure to desflurane (MAC. hrs) ‐Consumption of desflurane (ml) ‐Consumption of mivacurium (mg) ‐Consumption of fentanyl (µg) ‐Time to verbal response (min) ‐Time to extubation (min) ‐Time to orientation (min) ‐Time to PACU stay (min) ‐Time to oral intake (min) ‐Time to home readiness (min) ‐Patients with recall awareness ‐Patients with increased airway pressure ‐Patient with coughing and bucking
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	" Patients were randomly assigned to one of four study groups according to a computer‐generated random numbers table."
Allocation concealment (selection bias)	Unclear risk	The study has not mentioned about the allocation concealment
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing outcome data
Selective reporting (reporting bias)	Low risk	All expected outcomes were 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	"In the BIS‐titrated groups, the volatile anaesthetics were titrated to maintain a BIS index of 60." This indicates no blinding of anaesthesia care providers
Blinding of outcome assessors?	Unclear risk	The study has not mentioned about outcome assessor blinding