Impact of blood transfusion on major infection after isolated coronary artery bypass surgery: Incidence and risk factors

BACKGROUND/AIM: Cardiac surgery is considered one of the conditions that require a transfusion of blood and blood products in large amount. Infections are one of the most common complications after cardiac surgery. The aim of this study is to assess the impact of blood transfusion on major infections after isolated coronary artery bypass surgery (CABG). METHODS: A retrospective cohort study was conducted at King Abdulaziz Cardiac Center. Eligible adult patients, aged >18 years, who underwent an isolated CABG from 2015 to 2016, were included. Patient demographic information, as well as pre-, intra-, and postoperative data were collected from the electronic hospital information system charts and perfusion records. For data analysis, categorical pre- and postoperative variables were summarized by frequencies and percentages, whereas for continuous variables, means and standard deviation or median and interquartile ranges were used. RESULTS: The sample size was 459 patients. Red blood cells (RBCs) were transfused in 60.1% of the patients, and the median number of units transfused per patient was 2. The mean hemoglobin threshold for transfusion was 8.2 (standard deviation ± 3.6) g/dL. The mean EuroSCORE of RBC recipients was 3.8 ± 5.9% and that of non-RBC recipients was 2.0 ± 2.0%. In both groups (RBC recipients and non-RBC recipients), the most frequent infections after CABG were pneumonia (12% and 8.7%, respectively), deep surgical site infection (3.6% and 0.5%, respectively), and superficial sternal infection (6.9% and 3.8%, respectively), with a statistically significant difference (all p < 0.05). Patients receiving a blood transfusion at any stage during the intraoperative or postoperative period were 2.6 times more likely to develop an infection compared with those who did not receive a blood transfusion. The recipients of a blood transfusion experienced a longer hospital stay compared with the non-recipients at 11.5 ± 9.8 days versus 8.7 ± 3.4 days, respectively. CONCLUSIONS: Blood transfusion appears to increase the risk of infection post-CABG. However, increased understanding of the role of other potential clinical confounding variables that may impact the infection rate is required. We recommend management strategies that limit RBC transfusion.