Liberal or restrictive fluid management during elective surgery: a systematic review and meta-analysis

Schol PB, Terink IM, Lancé MD, Scheepers HC. J Clin Anesth. 2016 Dec

Although we have 8 large randomized trials comparing restrictive to liberal strategies for RBC transfusion, not as much attention has been directed to strategies for IV fluid administration. Since fluid administration can directly influence transfusion rates, this is an important parameter to study. The current study examined the outcomes of each management policy during elective surgery.
Meta-analysis of three randomized controlled trials performed during elective surgeries with patients randomly assigned to a restrictive fluid management policy or to a liberal fluid management policy during elective surgery was done. The patient characteristics and the type of surgery varied. All but 3 studies reported American Society of Anesthesiologists groups 1 to 3 as the inclusion criterion.
The primary outcome of interest was total number of patients with a complication and the complication rate. Secondary outcome measures were infection rate, transfusion need, postoperative re-bleeding, hospital stay, and renal function. Appropriately, transfusion is clearly labeled as an adverse outcome.
In total, 1397 patients were analyzed (693 restrictive protocol, 704 liberal protocol). Meta-analysis showed that in the restrictive group as compared with the liberal group, fewer patients experienced a complication (relative risk [RR], 0.65; 95% confidence interval [CI], 0.55-0.78). The total complication rate (RR, 0.57; 95% CI, 0.52-0.64), risk of infection (RR, 0.62; 95% CI, 0.48-0.79), and transfusion rate (RR, 0.81; 95% CI, 0.66-0.99) were also lower. Postoperative re-bleeding did not differ between groups: RR, 0.76 (95% CI, 0.28-2.06).
The authors concluded that compared with a liberal fluid policy, a restrictive fluid policy in elective surgery results in a 35% reduction in patients with a complication and should be advised as the preferred fluid management policy.
As is often heard in research, the more data, the better. Over a thousand patients were included in this study, but a greater number of trials included and analyzed would have strengthened their position. Hopefully, future efforts in this field will give us a larger data pool to work with and more concrete results to guide and transform health policy.