Rothenberg 1998.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: 2 groups, monoprophylaxis
Participants	Baseline characteristics Droperidol Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): NA Received treatment (n): NA Analysed (n): 47 Age (mean ± SD, median (IQR), median (range)): 32 (17 to 45) Weight (mean ± SD, median (IQR), median (range)): 66 (45 to 95) BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 100 Non‐smoker (%): NA History of PONV/motion sickness (%): 8.5/14.9 Type of general anaesthesia: combined anaesthesia (N₂O, propofol) Duration of anaesthesia or surgery (in min; as mean or median): 40 Use of perioperative opioids (if yes, which?): 2.9 mg morphine, 1.5 µg/kg fentanyl Type of surgery: gynaecological laparoscopy Dexamethasone Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): NA Received treatment (n): NA Analysed (n): 48 Age (mean ± SD, median (IQR), median (range)): 32 (18 to 48) Weight (mean ± SD, median (IQR), median (range)): 65 (47 to 100) BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 100 Non‐smoker (%): NA History of PONV/motion sickness (%): 6.3/14.6 Type of general anaesthesia: combined anaesthesia (N₂O, propofol) Duration of anaesthesia or surgery (in min; as mean or median): 41.5 Use of perioperative opioids (if yes, which?): 3.4 mg morphine, 1.5 µg/kg fentanyl Type of surgery: gynaecological laparoscopy Included criteria: ASA I or II, requiring outpatient gynaecological laparoscopy Excluded criteria: currently receiving antiemetic or corticosteroid therapy; history of immunosuppression, peptic ulcer disease, diabetes mellitus, hypertension, recent tuberculosis, Cushing’s syndrome, or cataracts Pretreatment: baseline characteristics (age, weight, ASA): no. Potential effect modifiers (gender, duration of anaesthesia, history of PONV/motion sickness, perioperative opioids): no; (non‐smoker): unclear
Interventions	Intervention characteristics Droperidol Dose: 0.02 mg/kg Time point of administration: before abdominal incision Route of administration: IV Rescue antiemetics (if yes, which?): metoclopramide, ondansetron, prochlorperazine, droperidol, or ephedrine, alone or in combination Dexamethasone Dose: 0.17 mg/kg Time point of administration: before abdominal incision Route of administration: IV Rescue antiemetics (if yes, which?): metoclopramide, ondansetron, prochlorperazine, droperidol, or ephedrine, alone or in combination
Outcomes	Vomiting (PACU) Outcome type: dichotomous outcome Vomiting (discharge to 24 hours) Outcome type: dichotomous outcome PONV (0 to 24 hours) 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: USA Setting: outpatient, single‐centre Author's name: David M. Rothenberg Institution: Department of Anesthesiology, Rush‐Presbyterian‐St. Luke's Medical Center, Chicago, Illinois, USA Email: NA Address: Department of Anesthesiology, Rush‐Presbyterian‐St. Luke's Medical Center, 1653 W. Congress Parkway, Chicago, Illinois, USA Duration of study: NA Language: English Study's primary outcome: incidence of PONV Trial registry number: NA
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "the purpose of this randomized..." Judgement comment: no information on sequence generation provided
Allocation concealment (selection bias)	Unclear risk	Judgement comment: no statement
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "unlabeled numbered aliquots of the study drugs were prepared in equal volumes by an operating room pharmacist without knowledge of the study design"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "within 24 h a blinded observer telephoned each patient to inquire about additional postoperative complications" Quote: "...by a nurse not directly participating in the study"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "five patients (5%) were excluded from data analysis due to the need to perform surgical laparotomy (2 patients) and failure to achieve telephone contact (3 patients). Of the remaining 95 patients, 47 were assigned to the droperidol group, and 48 were assigned to the dexamethasone group"
Selective reporting (reporting bias)	Unclear risk	Judgement comment: no reference to a study protocol or trial registry number reported
Other bias	Unclear risk	Quote: "...assigned to the dexamethasone group. There were no differences between the two groups in relationship to patient age, weight, prior episodes of PONV, preoperative history of motion sickness, timing of menses, duration of surgery, amount of IV fluid or vecuronium administered or propofol maintenance dosage (Table 1)..." Judgement comment: baseline characteristics (age, weight, ASA): no. Potential effect modifiers (gender, duration of anaesthesia, history of PONV/motion sickness, perioperative opioids): no; (non‐smoker): unclear