Meta-analysis of standard, restrictive and supplemental fluid administration in colorectal surgery

Background: Optimal fluid therapy for colorectal surgery remains uncertain. Methods: A simple model was applied to define standard, restrictive and supplemental fluid administration. These definitions enabled pooling of data from different trials. Randomized controlled trials on fluid amount (standard versus restrictive or supplemental amount) and on guidance for fluid administration (goal-directed fluid therapy by oesophageal Doppler-derived variables versus conventional haemodynamic variables) in patients with colorectal resection were eligible for inclusion. The primary outcome measure was postoperative morbidity. Secondary endpoints were mortality, cardiopulmonary morbidity, wound infection, anastomotic failure, recovery of bowel function and hospital stay. A random-effects model was applied. Results: Nine randomized controlled trials were included. Restrictive fluid amount (odds ratio (OR) 0.41 (95 per cent confidence interval (c.i.) 0.22 to 0.77); P = 0.005) and goal-directed fluid therapy by means of oesophageal Doppler-derived variables (OR 0.43 (95 per cent c.i. 0.26 to 0.71); P = 0.001) significantly reduced overall morbidity. There were no significant differences in the secondary endpoints analysed. Conclusion: Using standardized definitions, this meta-analysis suggests that restrictive rather than standard fluid amount according to current textbook opinion, and goal-directed fluid therapy rather than fluid therapy guided by conventional haemodynamic variables, reduce morbidity after colorectal resection.