Monti 1999.

Methods	Design: prospective randomized controlled trial Country: USA Multisite: no International: no Treatment duration: preoperative period Follow‐up: until discharge from the ambulatory care unit Operative procedure(s): gynaecological laparoscopy Randomization unit: participants Analysis unit: individual
Participants	90 participants enrolled ASA I to II female participants aged 18 to 55 years undergoing non‐emergency ambulatory gynaecological laparoscopy Exclusion criteria included: pregnancy; history of nausea or vomiting. Randomized to: control group (n = 45, 50%); experimental group (n = 45, 50%); it was unclear from the information presented whether there were any withdrawals. Main characteristics of participants: information on the mean age of each group was not provided; it was stated that there was no difference in the mean age; number of females/males: 90/0.
Interventions	Control group (control): "the usual" amount of Ringer's lactate as dictated by the attending anaesthetist Experimental fluid group (intervention): preoperative bolus of 1 litre of Ringer's lactate Co‐interventions: none stated
Outcomes	The risk of nausea and vomiting were evaluated and reported as dichotomous outcomes. Overall risk for the duration participant's postanaesthetic care unit and ambulatory surgical unit stay (until time of discharge) was reported. Rescue antiemetic administration was also reported for the overall postoperative period.
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	Participants were randomly assigned using a random distribution table.
Allocation concealment (selection bias)	Unclear risk	Participants were randomly assigned using a random distribution table.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of participants and personnel was not described.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Blinding of outcome assessors was not described.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	The number of withdrawals was not stated and denominators were not provided for any reported results.
Selective reporting (reporting bias)	Low risk	All outcomes were reported.
Other bias	Low risk	There were no other sources of bias.