Abboud 1995a.

Methods	Study design: randomized parallel groups Study dates: not stated
Participants	Country: USA Sex: female Age: mean 28 to 29 ASA: not stated Procedure: caesarean delivery Study size: 75
Interventions	Randomized portion of anaesthetic: volatile agent doses Pre‐delivery: induction/maintenance Intervention 1: desflurane end‐tidal 3% (N = 25) Intervention 2: desflurane end‐tidal 6% (N = 25) Intervention 3: enflurane end‐tidal 0.6% (N = 25)
Outcomes	Primary outcomes: cbc chemistry urine analysis etc. Secondary outcome: awareness/wakefulness as defined using an awareness classification system (see Table 1): class 1 Quote: "none of the patients developed intraoperative awareness."
Notes	Non‐randomized portion of anaesthetic: parts of potent inhalational technique (volatile agent)/N2O yes/hypnotic/supplemental narcotics/muscle relaxants induction yes/unclear maintenance Rapid sequence induction regimen thiopental + succinylcholine Anaesthesia maintenance: before delivery N2O 50% and O2; after delivery N2O 67% + butorphanol 1 mg to 2 mg and reduced doses of desflurane and enflurane ROB survey emailed jsl3nov42@webtv.net
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "patients were randomly assigned"
Allocation concealment (selection bias)	Unclear risk	Comment: no information provided
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: anaesthesiologist and postoperative interviewer: no information provided
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: anaesthesiologist and postoperative interviewer: no information provided
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: no missing outcome data
Selective reporting (reporting bias)	Low risk	Comment: awareness outcome part of inclusion criteria
Other bias	Unclear risk	Comment: no information provided