Yilmaz 2014.

Methods	Design: double‐blind, prospective randomized controlled trial Country: Turkey Multisite: no International: no Treatment duration: intraoperative period Follow‐up: 24 hours postoperatively Operative procedure(s): tonsillectomy or adenotonsillectomy, or both Randomization unit: participants Analysis unit: individual
Participants	160 participants enrolled ASA I to II children aged 2 to 15 years undergoing elective tonsillectomy or adenotonsillectomy, or both Exclusion criteria included: history of diabetes; mental retardation; obesity (body mass index greater than 95th percentile for age and sex); intake of antiemetic or psychoactive medication within 24 hours before surgery; known gastroesophageal reflux. Randomized to: group 1 (n = 80, 50%); group 2 (n = 80, 50%); 6 patients were excluded from the study, 3 from each group, for failing to pass the inclusion and exclusion criteria. Main characteristics of participants: age: group 1: all < 18 years; group 2: all < 18 years; number of females/males: 80/80.
Interventions	Group 1 (control): intraoperative infusion of 10 mL/kg/hour normal saline Group 2 (intervention): intraoperative bolus of 20 mL/kg/hour normal saline Co‐interventions: none stated
Outcomes	Episodes of vomiting within the first 24 hours postoperatively were recorded and reported
Notes	Trial registration: NCT02177201 Funder: sponsored by Adnan Menderes University A priori sample size estimation: not stated Conducted: August 2013 to August 2014 Declared conflicts of interest: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants were randomly allocated, but no information on the randomization process was provided.
Allocation concealment (selection bias)	Unclear risk	Participants were randomly allocated, but no information on the allocation process was provided.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participants, care providers, and investigators were blinded.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The outcome assessor was blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	6 participants, 3 from each arm, were excluded after beginning the study due to "meeting exclusion criteria".
Selective reporting (reporting bias)	Low risk	All outcomes were reported. Data were presented as an intention‐to‐treat analysis.
Other bias	Low risk	There were no other sources of bias.