Prevalence and long-term implications of preoperative anemia in patients undergoing elective general surgery – a retrospective cohort study at a university hospital

Abstract

Objective: The aim of this retrospective study was to assess the prevalence of anemia in a cohort of patients undergoing elective general surgery at a university hospital. Furthermore, we investigated the influence of anemia on short-term and long-term postoperative outcome. Background: Awareness of the negative impact of preoperative anemia on perioperative morbidity and mortality is rising. Anemia is a potentially modifiable factor, and its therapy might improve patient outcome in elective surgery. Nevertheless, patients with preoperative anemia frequently undergo elective surgery without receiving adequate preoperative treatment. Methods: In this single-center cohort study, we analyzed 6908 adult patients who underwent elective general surgery. Patients undergoing day-clinic surgery were excluded. In all patients, preoperative hemoglobin (Hb) concentration and hematocrit (Hct) was available. Results: Of all patients analyzed, 32.9% were anemic (21.0% mild, 11.8% moderate, 1.1% severe). Median time to last follow up was 5.2 years. During the whole study period, 27.1% of patients died (1.2% died during the hospital stay); median time to death was 1.3 years. Patients with preoperative anemia had significantly higher mortality rates (P<0.001) and a higher probability of postoperative complications (P<0.001). Likewise, receiving blood transfusions was associated with a higher risk of death (P<0.001). Conclusion: This retrospective single-center analysis confirmed that preoperative anemia is common, and is a significant risk factor for unfavorable postoperative outcome. As anemia is a modifiable risk factor, the implementation of a PBM concept is crucial to reduce detrimental postoperative events associated with anemia.