We have previously demonstrated that blood transfusion (BT) was associated with post-operative complications in patients undergoing surgery for Crohn’s disease (CD), based on our institutional data registry. The aim of this study was to verify the association between perioperative BT and infectious complications in CD patients enrolled in the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database.

All CD patients undergoing surgery between 2005 and 2013 were identified from NSQIP. Variables were defined according to the ACS NSQIP guidelines. The primary outcome was infectious complications, including superficial, deep and organ/space surgical site infection, wound dehiscence, urinary tract infection, pneumonia, systemic sepsis and septic shock. Multivariate analyses were performed to assess the risk factors for post-operative infections.

All 10 100 eligible patients were included and 611 (6.0%) received perioperative BT. BT patients were older, lighter in weight and more likely to be functionally dependent. BT patients were more likely to have post-operative infectious complications than those without BT, including superficial surgical site infection (SSI) (10.8% vs 7.4%, p=0.002), deep SSI (3.3% vs 1.6%, p=0.003), organ/space SSI (14.2% vs 5.4%, p<0.001), pneumonia (3.8% vs 1.3%, p<0.001), urinary tract infection (3.9% vs 2.2%, p=0.006), sepsis (11.5% vs 4.5%, p<0.001) and sepsis shock (3.1% vs 0.8%, p<0.001). Multivariate analysis showed that intra- and/or post-operative BT was an independent risk factor for post-operative infectious complications (odds ratio [OR] = 2.2; 95% confidence interval [CI]: 1.8–2.7; p<0.001) and the risk increased with each administered unit of red blood cell (OR = 1.3, 95% CI: 1.2–1.5). Other independent factors were history of smoking, chronic heart disease, diabetes, hypertension and the use of corticosteroids. Pre-operative BT, however, was not found to be a risk factor to post-operative infections.

Intra- and/or post-operative, not pre-operative, BT was found to be associated with an increased risk for post-operative infectious complications in this CD cohort. Therefore, the timing and risks and benefits of BT should be carefully balanced.