Verheij 2006.

Methods	Randomised controlled trial
Participants	67 patients undergoing either vascular (n = 28) or cardiac surgery (n = 40) Exclusion criteria: age > 79 years and known anaphylactoid reactions to colloids
Interventions	1) 4% Gelatine (n = 16) 2) 6% HES (n = 18) 3) 5% HA (n = 18) A fourth group received normal saline
Outcomes	Death Haemodynamic variables
Notes	Follow‐up not clear
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	Adequate. Hospital pharmacy assigned patients via sealed enveloped method