OBJECTIVES: Cardiac surgery required perioperative red blood cell (RBC) transfusion in more than 40% of patients. However, there is clinical uncertainty over safety threshold for perioperative RBC transfusion. Therefore, the objective of this study to compare the clinical outcomes of restrictive and liberal RBC transfusion for patients with Cardiac Surgery.

METHODS : A systematic search on MEDLINE and Cochrane Central Register of Controlled Trials, was performed with pairing relevant keywords to identify English language articles for last 10 years. The eligible Randomized controlled trials (RCTs) evaluating the restrictive versus liberal RBC transfusion for patients with cardiac surgery. The Outcome measures were mortality, length of stay in hospital and intensive care unit (ICU). A random effects model was used to calculate the pooled mean difference (MD) and Peto odd ratios (OR) with 95% confidence interval (CI). Meta-analysis was performed by using RevMan 5.3 software.

RESULTS : A total 6 RCTs including 12,787 participants with 537 mortality reported. The mean age of patients was ranged with 59 to 72 years. Results from meta-analysis showed no significant differences found between the groups in the RBC transfusion related mortality [Peto OR 0.98; 95% confidence interval (CI) 0.82, 1.16; P=0.79]. There was no significant heterogeneity amongst the studies [I²=11%; P=0.34]. There was also no significant difference found in the hospital length of stay (days) [MD 0.24; 95% CI -0.14, 0.62, P=0.22]. However, there was significant difference in the ICU length of stay (hrs.) [MD 4.38; 95% CI 1.99, 6.77, P<0.001], favoring liberal RBC transfusion strategies.

CONCLUSIONS : The current study suggests that, restrictive strategies for RBC transfusion are as safe and effective as liberal strategies in patients undergoing cardiac surgery with short-term follow-up period. Furthermore, evidence from well controlled RCTs and real world studies with long term follow-up required to confirm the present findings.