Moretti 2003.

Methods	Design: randomized controlled trial Withdrawals: 2 Setting: single centre USA Sample size: 90
Participants	Age (mean): buffered (Hextend) arm 59, non‐buffered arm (Hespan) 58 Gender (M/F): not described ASA grade: I to III Surgery type: major elective general, gynaecological, orthopaedic, or urological with anticipated blood loss > 500 mL Surgery duration (mean): 4.6/4.8 hours Anaesthesia type: general
Interventions	Three arms, only 2 of which are included 30 participants were enrolled into the buffered (Hextend) arm, and 30 into the non‐buffered arm (Hespan). Trial fluids were given according to a protocol, to ensure adequate volume during the operation. In addition, each arm was given a maintenance dose of lactated Ringer's solution (a buffered fluid).
Outcomes	Postoperative nausea and vomiting, oedema up to 24 hours after surgery
Notes	These are the same participant data as in Martin 2002, but different outcomes are reported. Funding source: supported in part by a grant from BioTime, Inc. Declarations of interest: none disclosed
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated sequence
Allocation concealment (selection bias)	Low risk	Sealed envelopes
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Blinded to participants, trial conductors and assessors
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Independent research personnel unaware of participant's collected randomization data
Incomplete outcome data (attrition bias) All outcomes	Low risk	1 participant from each group did not proceed with fluid allocation.
Selective reporting (reporting bias)	Low risk	No evidence of selection bias. All proposed outcome measures adequately reported
Other bias	Unclear risk	One participant in each group fell out ‐ 1 did not need study fluid, and the other had surgery rescheduled. Analysis was completed on an intention‐to‐treat basis. Study was funded in part by BioTime Inc., which manufactures Hextend.