The Clinical Significance of Full Blood Count Day 1 Post-op After Total Joint Arthroplasty

Post-operative full blood counts (FBC) after unilateral total joint arthroplasty are standard practice in our institution. Current medications and surgical techniques have been successful in reducing blood loss during surgery. Consequently, standard post-operative protocol of phlebotomising patients to check haemoglobin (Hb) levels in the setting of normal vital signs may be considered anachronistic. We conducted an audit of our service to establish if day 1 phlebotomy for primary arthroplasty surgery was a required investigation for all patients. All primary total hip replacements (THR) and total knee replacements (TKR) performed in our unit between 21/03/19 and 21/09/2019 were included with pertinent data obtained from the Irish National Orthopaedic Registry (INOR); hospital records of pre- and post-operative Hb levels were also obtained. We audited a total of 113 patients. Overall transfusion rate was 4.4% (n = 5); 3.28% (n = 2) of primary THRs; 5.77% (n = 3) of primary TKRs. All THR patients transfused post-operatively had pre-operative anaemia, with no patient with a Hb within normal limits requiring transfusion. No correlation was identified between intraoperative blood loss and transfusion rates in our primary arthroplasty cohort. Transfusion rates are low at our institution. Pre-operative anaemia is an independent risk factor for transfusion. Universal routine post-operative FBCs are unnecessary. We recommend correction of pre-operative anaemia and judicious post-operative phlebotomy based on patient comorbidities.