Chin 2006.

Methods	Design: randomized controlled study Withdrawals: 10 participants excluded for protocol violations (from total 60 participants recruited) Setting: single hospital in Singapore Sample size: 50; 3 arms to the trial One arm consisted of participants who received a fluid formulation that was not relevant to this review (dextrose 5% in 0.9% saline). Details for this arm of the study are not extracted here.
Participants	Age (mean): 50/35 years Gender (M/F): 21/11 ASA grade: I or II Surgery type: elective surgery that was not expected to enter into a major body cavity, or to require intravenous fluid volume in excess of 500 mL in the first 2 hours of perioperative care. Covered orthopaedic, ENT, breast, minor general surgery Surgery duration (mean): 1.5/1.2 hours Anaesthesia type: general
Interventions	Intervention n = 16 Buffered arm ‐ 500 mL lactated Ringer's solution administered over 45 to 60 minutes Control n = 16 Non‐buffered arm ‐ 500 mL 0.9% normal saline administered over 45 to 60 minutes Co‐interventions: none
Outcomes	Serum glucose and electrolytes, measured up to 1 hour postoperatively
Notes	This trial was performed on participants undergoing only minor surgery, who received only a small amount of intravenous fluid. Study was designed to investigate effects on serum glucose of infusion fluids containing or not containing a small amount of glucose. It was not designed as a trial to compare effects of buffered vs non‐buffered fluids. Data were reported as means (95% CIs) and were converted into means (SDs) for analysis. Funding source: not disclosed Declarations of interest: not disclosed
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomized via a computer‐generated random number table and sealed opaque envelopes.
Allocation concealment (selection bias)	Low risk	See above.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Trial was blinded to participants and investigators (personal communication).
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not disclosed
Incomplete outcome data (attrition bias) All outcomes	High risk	A high proportion of participants (20%) dropped out owing to administration of non‐protocol intravenous fluids.
Selective reporting (reporting bias)	Low risk	No evidence of selection bias. All proposed outcome measures adequately reported
Other bias	Low risk	No evidence of other potential bias