Schramko 2010.

Methods	Randomised controlled trial
Participants	45 patients undergoing elective cardiac surgery. Exclusion criteria: known coagulation disorder; renal or hepatic failure; preoperative left ventricular ejection fraction < 40%; received warfarin, heparin, clopidogrel, or acetylsalicylic acid within previous 5 days
Interventions	1) 6% HES (n = 15) 2) 4% Gelatin (n = 15) 3) Ringer's acetate (n = 15)
Outcomes	Haemodynamic variables Units of RBC and FFP transfused
Notes	Follow‐up 18 hours postoperatively. Mortality data obtained from study author (relates to study period only, inhospital mortality not available
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	Adequate 'closed envelopes were prepared before the beginning of the study by a person who did not take part in the treatment of the study subjects'