Postoperative anaemia is associated with poor long term postoperative outcomes after elective colorectal oncologic surgery within an enhanced recovery after surgery pathway.

Background: Anaemia is an independent risk factor for poor perioperative outcomes after major abdominal surgery, and is associated with an increased risk of 30-day postoperative mortality after noncardiac surgery.

Objective: To investigate the frequency of postoperative anaemia and short- and long-term survival after colorectal oncologic surgery at a centre with a well-established Enhanced Recovery After Surgery (ERAS) program.

Methods: We conducted a retrospective cohort study of all patients undergoing elective colorectal oncologic surgery within an ERAS pathway at our institution between 2013 and 2017. Overall survival was calculated with the Kaplan-Meier log rank method and Cox proportional hazard regression based on anaemia at hospital discharge.

Results: A total of 680 patients were included. Patients with anaemia at discharge showed a lower overall survival at 5 years (53.9% vs. 44%, p 0.05). Patients who were anaemic at discharge had a lower 5-year overall survival (hazard ratio [HR] 95% CI 2.663 [1.619-4.379], p < 0.001). Kaplan-Meier survival and Cox regression proportional hazard survival for overall survival in the combined preoperative, postoperative, and RBC transfusion model were 1.55 (1.038 2.318) p = 0.032.

Conclusions: The combined prognostic value of preoperative anaemia, postoperative anaemia, and blood transfusion created a 40.7% higher risk of not surviving 5 years.