Factors associated with increased risk of postoperative blood transfusion in patients undergoing total hip arthroplasty at an Irish University Hospital.

Introduction: Approximately 7000 total hip arthroplasty (THA) surgeries occur in Ireland each year. A number of preoperative factors have been identified that increase the risk of postoperative blood transfusion after THA, including anaemia. The ability to identify patients at risk may allow preoperative management strategies to reduce blood transfusions. Data from Irish orthopaedic patients is currently lacking.

Aim: To investigate if preoperative anaemia and other factors are associated with postoperative blood transfusions in patients who undergo THA.

Methods: A retrospective cohort study of all patients who underwent THA in 2019 in SIVUH, Cork, using medical chart review.

Results: In total, 350 charts met the inclusion criteria, with 291 charts reviewed. 8.9% of the patients who underwent THA had preoperative anaemia. Among these, 19.2% had a postoperative blood transfusion, compared to 1.5% of patients who were not anaemic preoperatively. The odds of receiving a blood transfusion was 15.5 times greater in the preoperative anaemia group compared to the non-anaemic group. Increasing age and higher ASA scores were associated with preoperative anaemia and postoperative blood transfusions. Length of stay was increased by 2.2 days (p < 0.00016) if blood transfusion was required.

Conclusion: Preoperative anaemia was common in an Irish orthopaedic population undergoing THA. Preoperative anaemia predisposes patients to the greatest increased risk of postoperative blood transfusions. The other factors associated with the need for postoperative transfusion were ASA grade 3 or more and age greater than 65 years. Patients who received postoperative blood transfusions had a significantly increased length of hospital stay.