Murshed 2012.

Methods	Design: double‐blind, prospective randomized controlled trial Country: Bangladesh Multisite: no International: no Treatment duration: preoperative period Follow‐up: 24 hours postoperatively Operative procedure(s): elective laparoscopic surgery Randomization unit: participants Analysis unit: individual
Participants	90 participants enrolled ASA I to II participants aged 22 to 55 years undergoing elective laparoscopic surgery Exclusion criteria included: history of significant PONV; motion sickness; pregnancy; lactation; operative time exceeding 2 hours; fasting greater than 12 hours. Randomized to: group A (n = 30, 33.3%); group B (n = 30, 33.3%); group C (n = 30, 33.3%). Main characteristics of participants: age (mean, standard deviation): group A 35.67 years, 11.18; group B 30.87 years, 6.66; group C 36.20 years, 12.30; number of females/males: not stated.
Interventions	Group A (intervention): preoperative bolus of 15 mL/kg Ringer's lactate Group B (control): preoperative infusion of 1.5 mL/kg/hour Ringer's lactate "for the period of fasting" Group C (intervention): preoperative infusion of 1.5 mL/kg/hour Ringer's lactate "for the period of fasting" and metoclopramide 0.15 mg/kg IV before induction of anaesthesia Co‐interventions: none stated
Outcomes	Nausea, vomiting, and retching were assessed and reported as dichotomous outcomes using questionnaires. These outcomes were reported for the overall postoperative period as well as for the following time periods: 0 to 1, 1 to 6, and 6 to 24 hours postoperatively. Rescue antiemetic administration was recorded and reported. Total dose of postoperative tramadol was recorded and reported. Heart rate and mean arterial pressure were measured and reported in the preoperative, intraoperative, and postoperative periods.
Notes	Trial registration: not stated Funder: not stated A priori sample size estimation: not stated 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	The blind envelope method was used to randomize participants to groups.
Allocation concealment (selection bias)	Unclear risk	The blind envelope method was used to randomize participants to groups.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	The participant, anaesthesia provider, and PACU nurses were blinded to group allocation.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The study investigator was blinded to group allocation.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No withdrawals were stated.
Selective reporting (reporting bias)	Low risk	All outcomes were reported.
Other bias	Low risk	There were no other sources of bias.