Lee YC 2009.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: 2 groups, monoprophylaxis
Participants	Baseline characteristics Hartmann's solution (group 1) Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 30 Received treatment (n): NA Analysed (n): 30 Age (mean ± SD, median (IQR), median (range)): 50.5 ± 10.5 Weight (mean ± SD, median (IQR), median (range)): 61.1 ± 9.4 BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 60 Non‐smoker (%): 66.67 History of PONV/motion sickness (%): 0 Type of general anaesthesia: inhalational anaesthesia (N₂O, sevoflurane) Duration of anaesthesia or surgery (in min; as mean or median): 60.2 Use of perioperative opioids (if yes, which?): 2 μg/kg fentanyl intraoperative, 0.5 mg/kg meperidine as rescue analgesia Type of surgery: laparoscopic cholecystectomy Ondansetron (group 3) Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 30 Received treatment (n): NA Analysed (n): 30 Age (mean ± SD, median (IQR), median (range)): 49.2 ± 8.5 Weight (mean ± SD, median (IQR), median (range)): 62.0 ± 9.3 BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 60 Non‐smoker (%): 63.33 History of PONV/motion sickness (%): 0 Type of general anaesthesia: inhalational anaesthesia (N₂O, sevoflurane) Duration of anaesthesia or surgery (in min; as mean or median): 59.8 Use of perioperative opioids (if yes, which?): 2 μg/kg fentanyl intraoperative, 0.5 mg/kg meperidine as rescue analgesia Type of surgery: laparoscopic cholecystectomy Included criteria: ASA I or II, presented for laparoscopic cholecystectomy, 19 to 60 years of age Excluded criteria: previous cardiopulmonary disease, endocrine disease, obesity, renal disease, received intravenous antibiotics within 1 week of operation, history of nausea and vomiting or motion sickness, were operated on for longer than 80 minutes, switched laparoscopic surgery for laparotomy Pretreatment: baseline characteristics (age, weight, ASA): no. Potential effect modifiers (gender, duration of anaesthesia, non‐smoker, history of PONV/motion sickness): no; (perioperative opioids): unclear
Interventions	Intervention characteristics Hartmann's solution (group 1) Dose: 5 ml/kg/h Time point of administration: before induction of anaesthesia Route of administration: IV Rescue antiemetics (if yes, which?): ondansetron 4 mg Ondansetron (group 3) Dose: ondansetron 4 mg, Hartmann's solution 5 mL/kg/h Time point of administration: before induction of anaesthesia Route of administration: IV Rescue antiemetics (if yes, which?): ondansetron 4 mg
Outcomes	PONV (0 to 24 hours) Outcome type: dichotomous outcome
Identification	Sponsorship source: NA Country: South Korea Setting: inpatient, single‐centre Author's name: Yong Cheol Lee Institution: Department of Anesthesiology and Pain Medicine, School of Medicine, Keimyung University Email: yclee@dsmc.or.kr Address: 194, Dongsan‐dong, Jung‐gu, Daegu 700‐712, Korea Duration of study: NA Language: Korean (Google Translator) Study's primary outcome: NA Trial registry number: NA
Notes	Two out of 3 groups relevant (large fluid volume)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Judgement comment: quote: "were randomized". No further information on sequence generation provided
Allocation concealment (selection bias)	Unclear risk	Judgement comment: no statement
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Judgement comment: no statement
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Judgement comment: quote: "one of the recovery anaesthesiologists who did not know the group of the study subjects observed the condition of the patient or interviewed the patient at 1 hour in the recovery room, and 12 hours and 24 hours after the operation" (translated)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Judgement comment: no missing outcome data
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 (age, weight, ASA): no. Potential effect modifiers (gender, duration of anaesthesia, non‐smoker, history of PONV/motion sickness): no; (perioperative opioids): unclear