Abstract
Total hip and knee arthroplasty is known to have a significant blood loss averaging 3–4 g/dL. Historically, transfusion rates have been as high as 70%. Despite years of work to optimise blood management, some published data suggests that transfusion rates (especially with allogeneic blood) are rising. There is wide variability between surgeons as well, suggesting that varying protocols can influence transfusion rates. Multiple studies now associate blood transfusions with negative outcomes including increased surgical site infection, costs, and length of stay.
Preoperative measures can be employed. Identify patients that are at increased risk of blood transfusion. Smaller stature female patients, have pre-operative anemia (Hgb less than 13.0 gm/dl), or are undergoing revision or bilateral surgery are at high risk. We identify these patients and check a hemoglobin preoperatively, using a non-invasive finger monitor for screening. For anemic patients, iron administration (oral or IV) can be given, along with Procrit/Epogen in select cases. Insurance coverage for that medication has been challenging.
Intraoperative measures that have been linked to reduced postoperative transfusions include regional anesthesia and intraoperative hypotension (mean arterial pressure <60mm/hg). Lowering the surgical time by practicing efficient, organised, and quality surgery, along with leaving a dry field at the completion of surgery can reduce blood loss.
Tranexemic acid (TXA) is an antifibrinolytic agent that has been shown to be effective, reducing average blood loss by 300 cc per case. There are multiple different administration protocols: IV using either a weight-based dosing 10–20 mg/kg or standardised dosing for all patients. Our current regimen is 1 gm IV preoperatively, 1 gm IV in PACU. Topical TXA can be used, usually 2–3 gm mixed in 50–100 cc of saline, sprayed in wound and allow to soak for 3–5 minutes. Oral administration is attractive for ease of use and reduced cost, standard oral dosing is 1950 mg PO 2 hours prior to surgery.
The American Association of Hip and Knee Surgeons, in collaboration with the American Association of Orthopedic Surgeons, American Society of Regional Anesthesiologists, and the Hip & Knee Society have developed a Clinical Practice Guideline with 8 recommendations for TXA as follows: All individual formulations are effective at reducing blood loss – strong; No method of administration is clearly superior at reducing blood loss and the risk of transfusion; The dose of IV or topical TXA does not significantly affect the drug's ability to reduce blood loss and risk of transfusion; Multiple doses of IV or oral TXA compared to a single dose does not significantly alter the risk of blood transfusion; Pre-incision IV TXA administration potentially reduces blood loss and risk of transfusion compared to post-incision administration; Administration of all TXA formulations in patients without history of VTE does not increase the risk of VTE; Administration of all TXA formulations in patients with a history of VTE, MI, CVA, TIA, or vascular stent does not appear to increase the risk of VTE; Administration of all TXA formulations does not appear to increase the risk of arterial thrombotic events; Postoperative measures to reduce transfusion rates include changing transfusion triggers. Instead of treating a “number”, use lower thresholds and employ safe algorithms established.
In conclusion, a comprehensive blood management program can reduce transfusion rates to less than 3% for THA and 1% for TKA and facilitate outpatient total joint arthroplasty.
