Dsouza 2011.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: 3 groups, monoprophylaxis, dose‐finding study
Participants	Baseline characteristics Dexamethasone (4 mg group) Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 31 Received treatment (n): NA Analysed (n): 31 Age (mean ± SD, median (IQR), median (range)): NA Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA Gender (female in %): 100 Non‐smoker (%): NA History of PONV/motion sickness (%): NA/0 Type of general anaesthesia: inhalational anaesthesia (sevoflurane, N₂O) Duration of anaesthesia or surgery (in min; as mean or median): NA Use of perioperative opioids (if yes, which?): 2 μg/kg of fentanyl for induction, 1.5 mg/kg tramadol as rescue analgesia Type of surgery: laparoscopic gynaecological surgery Dexamethasone (8 mg group) Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 31 Received treatment (n): NA Analysed (n): 30 Age (mean ± SD, median (IQR), median (range)): NA Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA Gender (female in %): 100 Non‐smoker (%): NA History of PONV/motion sickness (%): NA/0 Type of general anaesthesia: inhalational anaesthesia (sevoflurane, N₂O) Duration of anaesthesia or surgery (in min; as mean or median): NA Use of perioperative opioids (if yes, which?): 2 μg/kg of fentanyl for induction, 1.5 mg/kg tramadol as rescue analgesia Type of surgery: laparoscopic gynaecological surgery Ondansetron Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 31 Received treatment (n): NA Analysed (n): 31 Age (mean ± SD, median (IQR), median (range)): NA Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA Gender (female in %): 100 Non‐smoker (%): NA History of PONV/motion sickness (%): 0 Type of general anaesthesia: inhalational anaesthesia (sevoflurane, N₂O) Duration of anaesthesia or surgery (in min; as mean or median): NA Use of perioperative opioids (if yes, which?): 2 μg/kg of fentanyl for induction, 1.5 mg/kg tramadol as rescue analgesia Type of surgery: laparoscopic gynaecological surgery Included criteria: women aged 20 to 60 years with ASA grade I or II, scheduled for gynaecological laparoscopic surgery (e.g. laparoscopic ovarian cystectomy, adhesiolysis, Burch suspension, ovarian drilling, myomectomy, tubal reanastomosis, tubal patency test) under general anaesthesia with endotracheal intubation Excluded criteria: physical status ASA III or above; lactating or menstruating; taking any medication, including corticosteroids (except oral contraceptive pills); history of motion sickness; had not complied with 6 hours of preoperative fasting; gastrointestinal disorders; had received opioids, antiemetics, or steroids in the previous month; had previous hypersensitivity to these drugs Pretreatment: baseline characteristics (ASA): no; (age, weight): unclear. Potential effect modifiers (gender, history of motion sickness): no; (history of PONV, duration of anaesthesia, non‐smoker, perioperative opioids): unclear
Interventions	Intervention characteristics Dexamethasone (4 mg group) Dose: 4 mg Time point of administration: 5 minutes before induction Route of administration: IV Rescue antiemetics (if yes, which?): 0% (metoclopramide 10 mg) Dexamethasone (8 mg group) Dose: 8 mg Time point of administration: 5 minutes before induction Route of administration: IV Rescue antiemetics (if yes, which?): 6.7% (metoclopramide 10 mg) Ondansetron 4 mg Dose: 4 mg Time point of administration: 5 minutes before induction Route of administration: IV Rescue antiemetics (if yes, which?): 16.1% (metoclopramide 10 mg)
Outcomes	Vomiting (0 to 24 hours) Outcome type: dichotomous outcome Vomiting (0 to 3 hours) Outcome type: dichotomous outcome Vomiting (3 to 6 hours) Outcome type: dichotomous outcome Nausea (0 to 24 hours) Outcome type: dichotomous outcome Complete response (no PONV) in 24 hours Outcome type: dichotomous outcome Headache (overall, exact time point unknown) Outcome type: dichotomous outcome Adverse events (general notes in the publication, 24 hours' observation) Outcome type: general notes on side effects
Identification	Sponsorship source: NA Country: India Setting: inpatient, single‐centre Author's name: Nita D'souza Institution: Department of Anesthesia and Intensive care, All India Institute of Medical Sciences, New Delhi, India Email: drnita610@yahoo.com Address: Doctor's Hostel, Room No. 2, JPNA Trauma Centre, AIIMS, New Delhi‐110029, India. Tel.: +91 9953008488 Language: English Duration of study: NA Trial registry number: NA Study's primary outcome: NA
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "the participants underwent simple randomization into 3 groups" Judgement comment: no further information on sequence generation provided
Allocation concealment (selection bias)	Unclear risk	Judgement comment: no statement on allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "open‐label" Judgement comment: study was not blinded
Blinding of outcome assessment (detection bias) All outcomes	High risk	Judgement comment: study was not blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "among the 93 patients enrolled, 1 patient from the Dexa 8 group was excluded because she failed to comply with the nil‐per‐mouth criterion"
Selective reporting (reporting bias)	Unclear risk	Judgement comment: no reference to a study protocol or trial registry number reported
Other bias	Unclear risk	Judgement comment: baseline characteristics (ASA): no; (age, weight): unclear. Potential effect modifiers (gender, history of motion sickness): no; (history of PONV, duration of anaesthesia, non‐smoker, perioperative opioids): unclear