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

Objective: The aim of this retrospective study was to assess the prevalence of anaemia in a cohort of patients undergoing elective general surgery at a university hospital. Furthermore, the authors investigated the influence of anaemia on short-term and long-term postoperative outcome.

Background: Awareness of the negative impact of preoperative anaemia on perioperative morbidity and mortality is rising. Anaemia is a potentially modifiable factor, and its therapy might improve patient outcome in elective surgery. Nevertheless, patients with preoperative anaemia frequently undergo elective surgery without receiving adequate preoperative treatment.

Methods: In this single-centre cohort study, the authors analyzed 6908 adult patients who underwent elective general surgery. Patients undergoing day-clinic surgery were excluded. In all patients, preoperative haemoglobin concentration and haematocrit was available.

Results: Of all patients analyzed, 32.9% were anaemic (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 anaemia 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-centre analysis confirmed that preoperative anaemia is common, and is a significant risk factor for unfavourable postoperative outcome. As anaemia is a modifiable risk factor, the implementation of a patient blood management concept is crucial to reduce detrimental postoperative events associated with anaemia.