Perioperative Allogeneic Red Blood Cell Transfusion and Wound Infections: An Observational Study.

BACKGROUND It remains unclear whether the benefits of performing perioperative allogeneic red blood cell (RBC) transfusion outweigh the risks of postoperative wound infection. The aim of this study was to assess the impact of perioperative RBC transfusion as well as dose-response relationship on wound infections in surgical patients in a large cohort. METHODS As a retrospective observational study, the national Hospital Quality Monitoring System database was used to retrieve information about in-hospital surgical patients without limitations on surgical types in the People's Republic of China between 2013 and 2018. Patients were divided into the perioperative RBC transfusion and non-RBC transfusion groups, and wound infection rates (the primary end point) were compared. Secondary end points included in-hospital mortality, nosocomial infections, and length of hospital stay. Furthermore, patients who underwent RBC transfusion were subdivided into 6 groups based on the volume of transfused RBCs to investigate the dose-response relationship between RBC transfusions and wound infections. The association between RBC transfusion and patient outcomes were analyzed using multivariable logistic regression models adjusted for potential confounders. RESULTS A total of 1,896,584 patients from 29 provinces were included, among whom 76,078 (4.0%) underwent RBC transfusions; the overall wound infection rate was 0.7%. After adjusting for confounding factors, perioperative RBC transfusion was associated with higher odds of wound infection (odds ratio [OR] = 2.24, 95% confidence interval [CI], 2.09-2.40; P 0 and ≤1 U, >1 and ≤2 U, >2 and ≤4 U, >4 and ≤8 U, >8 U transfusion compared with no RBC transfusion were 1.20, 95% CI, 0.76-1.91; 1.27, 95% CI, 1.10-1.47; 1.70, 95% CI, 1.49-1.93; 2.12, 95% CI, 1.83-2.45 and 3.65, 95% CI, 3.13-4.25, respectively). RBC transfusion was also found to be associated with higher odds of in-hospital mortality, nosocomial infection, and longer hospital stay. CONCLUSIONS RBC transfusion was associated with an increased odd of postoperative wound infection in surgical patients, and a significant dose-related relationship was also observed. While there are still essential confounders not adjusted for and the results do not necessarily indicate a causal relationship, we still recommend to lessen perioperative blood loss and optimize blood conservation strategies.