Ali 2003.

Methods	Design: double‐blind, prospective randomized controlled trial Country: USA Multisite: no International: no Treatment timing: preoperative period Follow‐up: 24 hours postoperatively Operative procedure(s): laparoscopic or gynaecological surgery Randomization unit: participants Analysis unit: individual
Participants	80 participants enrolled ASA I to II males and females aged 18 to 70 years undergoing laparoscopic or gynaecological surgery lasting at least 1 hour Screened participants were excluded if they: experienced nausea or vomiting on the morning of surgery; were taking antiemetic drugs; had a documented disorder of the cardiovascular, hepatic, renal, gastrointestinal, or neurological systems. Randomized to: supplemental fluid (n = 40, 50%); conservative fluid (n = 40, 50%). No withdrawals were stated. Main characteristics of participants: age (mean, com deviation): supplemental group 39 years, 10; conservative group 41 years, 11; number of females/males: 70/4 (6 not stated).
Interventions	Supplemental fluid group (intervention): preoperative bolus of 15 mL/kg Ringer's lactate Conservative fluid group (control): preoperative bolus of 2 mL/kg Ringer's lactate Co‐interventions: none stated
Outcomes	Primary outcomes: Nausea was assessed by 100 mm visual analogue scale at 15‐minute intervals throughout PACU recovery (1 hour). A score of 50 mm or greater was considered significant. Episodes of vomiting and the need for rescue antiemetics in PACU were noted. Patients were called the following day and nausea (100 mm visual analogue scale) and vomiting (episodes) in the post‐discharge period were documented. Outcomes were reported in the following time periods: 0 to 1 hour, 1 to 24 hours, and 0 to 24 hours postoperatively Secondary outcomes included: admission to hospital after discharge.
Notes	Trial registration: not found Funder: none stated A priori sample size estimation: stated on page 782 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	Randomization was based on computer‐generated codes that were maintained in sequentially numbered, opaque envelopes.
Allocation concealment (selection bias)	Unclear risk	Randomization was based on computer‐generated codes that were maintained in sequentially numbered, opaque envelopes.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	The anaesthesia provider, the postoperative study investigator, and the PACU nurses were blinded to allocation of the groups, as were the participants.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The anaesthesia provider, the postoperative study investigator and the PACU nurses were blinded to allocation of the groups, as were the participants.
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.