Page 27 - ISAKOS 2018 Newsletter Volume 2
P. 27

More specifically, it was also demonstrated superior efficiency and easier administration procedures with ferric carboxymaltose compared with iron sucrose. It should be noted that intravenous administration of ferric carboxymaltose may pose a rare but significant risk of anaphylaxis and therefore in-hospital administration and monitoring should be considered.
Erythropoietin is a powerful synthetic hormone that activates hematopoiesis, but it is expensive and we are not routinely using it at our institution for the treatment of preoperative anemia.
Another aspect of the preoperative assessment is managing the routine administration of antiplatelet or anticoagulant medication in order to reduce perioperative blood loss. The decision and timing of cessation of such medication before surgery must weigh the risk of bleeding against the risk of thrombosis. At our institution, patients receiving warfarin are asked to stop taking their anticoagulant medication 5 days prior to surgery. In order to minimize their thrombotic risk, those patients are managed with bridge therapy with low molecular-weight heparin during that time and with resumption of their previous anticoagulant medication immediately postoperatively. We also routinely stop antiplatelet medication, aspirin, and more modern anticoagulants (i.e., thrombin inhibitors and factor-Xa inhibitors) 5 to 7 days preoperatively and restart the medication immediately postoperatively. When a patient has undergone recent cardiac stenting (within 1 year previously), the opinion of the cardiologist is sought to evaluate the risk of thrombosis and the potential for a cardiac event if the anticoagulant medication is stopped.
Since we introduced this simple Hgb screening and optimization program at our institution, the blood transfusion rate has dropped significantly despite an increased volume of TKR surgery. An internal audit revealed that the rate of blood transfusion in our clinic decreased from 6.6% (21 of 317) in 2011 to 0.12% (1 of 812) in 2017 (unpublished data).
Intraoperative Blood-Management Protocol
Surgical factors such as the difficulty and duration of the procedure along with patient-related factors such as comorbidities, high BMI, and bleeding disorders have an impact on intraoperative blood loss. Employing an efficient surgical technique with careful dissection, soft-tissue handling, and meticulous hemostasis based on the detailed vascular anatomy around the knee joint is paramount for achieving good bleeding control and minimizing intraarticular blood loss. Additional factors that should be considered as part of the intraoperative blood-management strategy are briefly discussed below.
Use of Tranexamic Acid (TXA)
TXA is a synthetic form of lysine that prevents fibrinolysis by blocking the receptor site on plasminogen, thus preventing binding to fibrin and subsequent clot degradation.
The use of TXA in surgery in general and arthroplasty in particular has been reported widely; it is most commonly administered intravenously but also can be administered orally and topically. Multiple Level-I studies of patients undergoing TKR have shown that the perioperative administration of TXA has been associated with significant reductions in postoperative bleeding and the rate of blood transfusion, without an increase in the risk of venous thromboembolism. A recent meta-analysis of RCTs evaluating the effectiveness of TXA in primary TKR surgery showed that, when compared with placebo, TXA reduced blood loss by roughly 500 mL and resulted in 1.43 fewer units of blood being transfused per patient. There is, however, no clear consensus on the ideal dosage, timing, and route of administration for TXA in TKR surgery. The current recommendation for intravenous TXA is a single dose of 10 to 15 mg/kg. Both oral and topical administration of TXA have shown similar effectiveness to intravenous administration, and some authors have recommended a combined form of TXA administration. At our institution, we use a combination of single intravenous dose of TXA (15 mg/kg) before releasing the tourniquet and applying topical TXA (2 g) before skin closure.
Use of Tourniquet
Tourniquet usage in TKR surgery is still common practice among arthroplasty surgeons. A 2010 survey indicated that 95% of arthroplasty surgeons in North America use a tourniquet during TKR surgery, and the National Joint Registry in the United Kingdom reported that 93% of primary knee replacements in 2003 were performed under tourniquet control. The proposed advantages of routine tourniquet usage include improved visualization, decreased intraoperative blood loss, lower transfusion rates, and, possibly, superior cementation of components.
Recent awareness has been raised about the potential detrimental functional effects that result from routine tourniquet use. The use of a tourniquet may be a risk factor for postoperative thromboembolism, minor wound complications, and increased postoperative pain related to tissue hypoxia and reperfusion injury. Persistent lower postoperative quadriceps strength at 3 months of follow-up also has been reported in association with use of a tourniquet during TKR surgery. Some authors have recommended using a tourniquet during cementation of the components only. However, recent studies have suggested that TKR surgery that is performed without the use of tourniquet does not influence component fixation in the short term.

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