Hachero 2001

Methods	RCT
Participants	Country: Spain N = 40 ASA: I/II Gender: female Age: 18‐65 years Exclusion: extreme obesity, cardiovascular and metabolic illnesses, hepatic or renal diseases and history of abuse of alcohol or drugs Operation: gynaecologic procedures including myomectomy, hysterectomy, oophorectomy and infra‐umbilical laparotomy Duration of anaesthesia: 73 (64‐82), 64 (56‐74)
Interventions	Propofol administration guided by BIS (TO‐2000 with electrodes BIS‐Sensor, Aspect Medical Systems Inc., USA), BIS value of 40‐60 during maintenance (BIS group), Cn = 20 Propofol 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 or autonomic responses)(CS group), Cn = 20
Outcomes	‐Total dose of fentanyl during maintenance (main outcome) ‐Propofol used during maintenance (mg)
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Using random numbers table
Allocation concealment (selection bias)	Unclear risk	No mention about the allocation concealment
Incomplete outcome data (attrition bias) All outcomes	Low risk	All patients included in the analysis
Selective reporting (reporting bias)	Low risk	All expected outcomes have been reported
Other bias	Unclear risk	The unblinded anaesthesiologists could potentially lead to 'learning contamination bias'
Blinding of patients?	Low risk	Patients were anaesthetized
Blinding of anaesthesiologists?	High risk	According to Ivan Sola (translator) "The propofol perfusion was controlled on depending of the BIS values to maintain patients' values between 40 and 60". This indicates no blinding of the anaesthesia care providers
Blinding of outcome assessors?	Low risk	According to Ivan Sola (translator) ".. Nurse on the PACU assessed blinded the patients' self reported pain level'