Multicentre cohort study of red blood cell use for revision hip arthroplasty and factors associated with greater risk of allogeneic blood transfusion

Background. Revision hip arthroplasty (RHA) is associated with high rates of allogeneic blood transfusion (ABT). We aimed to determine factors associated with ABT in patients undergoing RHA in Scottish hospitals, with particular focus on perioperative cell salvage (PCS). Methods. A prospective observational cohort study of RHA procedures performed in 11 hospitals over 7 months was performed. We recorded predefined patient, surgery-related, and blood conservation factors that may influence perioperative ABT, together with postoperative haemoglobin (Hb) data and ABTs to day 7. We explored factors with strongest independent association with ABT during the perioperative period using multiple regression analysis. Results. Two hundred and ten cases were studied, of whom 58% received ABTs (mean 1.8 units), most of which (52%) occurred on the day of surgery. Eighty-eight (42%) patients received PCS, of whom 68 had red cells re-infused [mean re-infusion volume 312 ml (1st, 3rd quartile: 260, 363 ml)]. In unadjusted comparisons, patients receiving PCS had lower intraoperative (9% vs 40%) and total (55% vs 63%) exposure to ABTs. The mean (95% confidence interval) theatre blood loss was 1013 (899-1128) ml and was higher for combined femoral/acetabular revision and femoral revision than other categories. The mean postoperative Hb transfusion trigger was 80 g litre 21. In multivariable models, preoperative Hb [odds ratio (OR) 0.35; P < 0.001], patient weight (OR 0.96; P = 0.004), operating theatre blood loss (OR 1.002; P < 0.001), and re-infusion of PCS blood (OR 0.31; P = 0.02) were independent predictors of ABT exposure. Conclusions. PCS is an effective blood conservation strategy for RHA, especially for patients with preoperative anaemia, low body weight, or both.