Dagher 2009.

Methods	Design: double‐blind, prospective randomized controlled trial Country: Lebanon Multisite: no International: no Treatment duration: preoperative period Follow‐up: 24 hours postoperatively Operative procedure(s): thyroidectomy Randomization unit: participants Analysis unit: individual
Participants	102 participants enrolled Male and female adults undergoing elective thyroidectomy for multinodular goitre or multinodular toxic goitre Exclusion criteria: history of congestive heart failure; history of hypertension; history of valvular heart disease; history of diabetes mellitus; history of epilepsy; established gastrointestinal disease; relevant drug allergy; receiving antiemetic medication in the 24 hours preceding the procedure. Randomized to: RL‐10 group (n = 51, 50%); RL‐30 group (n = 51, 50%); 1 participant from the RL‐10 group was excluded because of intraoperative antiemetic administration; 1 participant from the RL‐30 group was excluded for postoperative dexamethasone administration. Main characteristics of participants: age (mean, standard deviation): RL‐10 group 45.2 years, 10.9; RL‐30 group 39.4 years, 9.7; number of females/males: 79/21.
Interventions	RL‐10 group (control): preoperative bolus of 10 mL/kg Ringer's lactate RL‐30 group (intervention): preoperative bolus of 30 mL/kg Ringer's lactate Co‐interventions: none stated
Outcomes	Nausea, dry retching, and vomiting were assessed as dichotomous outcomes 30 minutes after emergence from anaesthesia and at 2, 6, 12, 18, and 24 hours postoperatively. The risk of nausea and vomiting at different time points were reported graphically. The risk of nausea, vomiting, nausea or vomiting, and nausea and vomiting were reported for the overall postoperative period. Antiemetic and analgesic administration documented. Patients' satisfaction concerning postoperative physical comfort and well‐being was recorded 24 hours after surgery with a 100 mm visual analogue scale. Nausea, dry retching, vomiting, and antiemetic administration were recorded at entry to PACU, and at postoperative hours 2, 6, 12, 18, and 24.
Notes	Trial registration: not stated Funder: not stated A priori sample size estimation: stated on page 188 Conducted: dates not stated Declared conflicts of interest: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random allocation was performed using a computer‐generated number table.
Allocation concealment (selection bias)	Unclear risk	Random allocation was performed using a computer‐generated number table.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	The anaesthesiologist taking care of the participant may have been aware of the group assignment, but the participant and PACU nurses were not.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Data collection was completed by a blinded observer.
Incomplete outcome data (attrition bias) All outcomes	Low risk	2 participants excluded for protocol violations, but no apparent material impact.
Selective reporting (reporting bias)	Unclear risk	Intention‐to‐treat analysis was not completed for 2 excluded participants. All outcomes were reported.
Other bias	Low risk	There were no other sources of bias.