Transfusion Strategy and Postoperative Complications in Adults Undergoing Cardiac and Vascular Surgery: Systematic Review and Meta-analysis

Background: Bleeding is frequent in cardiac and vascular surgery (CVS) having a greater need for transfusion. Studies have observed an increase in complications in transfused patients, and in this context the use of a liberal strategy (LS) was questioned, and a restrictive strategy (RS) gained space in the scientific environment. However, the effects of these strategies remain uncertain. This study aimed to verify if there is an association between the transfusion strategy and the occurrence of postoperative complications in adult patients undergoing CVS.

Methodology: Searches were performed in four databases and manually. The selection was made from studies with adult patients who underwent CVS that required transfusion, and the outcome variable was the complications arising from this procedure. The languages were restricted to Portuguese and English. The Stata software was used for meta-analysis.

Results: Six publications, involving 6,187 patients, were included. In four studies there was no evidence that the risk of mortality and adverse events differed among patients allocated to an RS transfusion versus an LS. On the other hand, two studies raised a possible RS inferiority, however, the meta-analysis demonstrated no statistically significant difference between the two strategies. Furthermore, another study also suggested that the number of red blood cell units transfused was an independent risk factor for the occurrence of complications.

Conclusions: RS is not inferior to LS in terms of postoperative complications in CVS, but other randomized clinical trials are necessary to better define the minimum allowed value for the RS.