The impact of anemia and blood transfusion on mortality after open abdominal surgery in the elderly

BACKGROUND: Major abdominal surgery is associated with considerable mortality in the elderly. Anemia has been linked to increased mortality in other types of surgery, such as hip and cardiac surgery. This study aimed to assess the impact of preoperative anemia on mortality in the elderly undergoing major abdominal surgery, and how allogeneic red cell blood transfusion influences mortality in these patients. MATERIALS AND METHODS: We conducted a single-center, register-based retrospective study on patients, who were aged beyond 60 years and underwent one of 81 open abdominal surgical procedures. Patients operated on during the period from January 1, 2000, to May 31, 2013, were consecutively identified in the Danish National Patient Registry. Plasma hemoglobin was measured within 30 days prior to surgery and the primary endpoint was 30-day postoperative mortality. Information about patient transfusions from the hospital blood bank was available from 1998 to 2010. RESULTS: A total of 3199 patients were included of whom 85% underwent emergency surgery. The total mortality after 30 days was 20%. The median preoperative hemoglobin value of survivors was 7.7 mmol/L vs 6.9 mmol/L in those who died. The difference in hemoglobin values, between those who survived or died, decreased from the pre- to the post-operative phase. The 30-day postoperative mortality was 28%, 20%, and 12% in patients with a preoperative hemoglobin level in the lower, median, and upper quartile respectively. Transfusion therapy was associated with higher postoperative mortality, except in patients with very low hemoglobin values. CONCLUSION: Preoperative anemia has a clear association with surgically related mortality. The distribution of hemoglobin values in patients with a fatal outcome differs significantly from that of survivors. Red cell transfusion is associated with increased mortality, except in patients with very low hemoglobin values which supports recent guidelines suggesting a restrictive transfusion strategy.