BACKGROUND: Major emergency abdominal surgery is associated with excess mortality. Transfusion is known to be associated with increased morbidity and emergency surgery is an independent risk factor for perioperative transfusion. The primary objectives of this study were to identify risk factors for transfusion, and secondarily to investigate the influence of transfusion on clinical outcomes after major emergency abdominal surgery.

STUDY DESIGN AND METHODS: This study combined retrospective observational data including intraoperative, postoperative, and transfusion data in patients undergoing major emergency abdominal surgery from January 2010 to October 2016 at a Danish university hospital. The primary outcome was a transfusion of any kind from initiation of surgery to postoperative day 7. Secondary outcomes included 7-, 30-, 90-day and long-term mortality (median follow-up = 34.6 months, IQR = 13.0-58.3), lengths of stay, and surgical complication rate (Clavien-Dindo score ≥ 3a).

RESULTS: A total of 1288 patients were included and 391 (30%) received a transfusion of any kind. Multivariate logistic regression identified age, hepatic comorbidity, cardiac comorbidity, post-surgical anemia, ADP-receptor inhibitors, acetylsalicylic acid, anticoagulants, and operation type as risk factors for postoperative transfusion. 60.1% of the transfused patients experienced a serious surgical complication within 30 days of surgery compared with 28.1% of the non-transfused patients (p < 0.001). Among patients receiving a postoperative transfusion, unadjusted long-term mortality was increased with a hazard ratio of 3.8 (95% CI 2.9-5.0), p < 0.01. Transfused patients had significantly higher mortality at 7-, 30-, 90- and long-term, as well as a longer hospital stay but in the multivariate analyses, transfusion was not associated with mortality.

CONCLUSION: Peri- and postoperative transfusion in relation to major emergency abdominal surgery was associated with an increased risk of postoperative complications. The potential benefits and harms of blood transfusion and clinical significance of pre- and postoperative anemia after major emergency abdominal surgery should be further studied in clinical prospective studies.