[Blood conservation approaches in orthopedic surgery]. / Epargne transfusionnelle en chirurgie orthopédique.

In addition to more restrictive "transfusion triggers", presently available allogeneic blood conservation strategies in surgery include preoperative increase in red blood cells (RBC) mass, techniques or pharmaceutical agents that reduce blood loss, and perioperative blood salvage. Because of very important risk reduction in allogeneic blood, benefit/risk of preautologous blood donation (PAD) is quite questionable at this moment. Indeed, at this moment in France, we focus to avoid any transfusion (allogeneic and autologous blood). Therefore the most important techniques used are pharmacological: erythropoietin before surgery with a number of injections related to baseline Hb, and tranexamic acid during and after surgery. Cell saving is used only if bleeding is enough important like arthroplasty revisions. All blood conservation techniques carry their own efficiency limits, constraints and risks that, in addition to institutional considerations and individual patient characteristics are determinant to settle a blood conservation strategy. The choice of a technique should take into account (a) the delay before surgery, (b) the anticipated blood loss for the procedure that varies among institutions, (c) the tolerable blood loss without transfusion for the patient, and (d) the efficacy of the blood conservation technique in the given setting. Nevertheless, at this moment in France, it is quite important to notice that the risk of delay or lack of transfusion induces much more deaths that the transfusion itself during or after anesthesia [Anesthesiology 105, 1087-97].

[Rivaroxaban (Xarelto): efficacy and safety]. / Rivaroxaban (Xarelto): efficacité et tolérance.

The oral direct Xa inhibitor rivaroxaban (Xarelto) shows great promise for prevention of venous thromboembolic events after major elective orthopedic surgery. Its consistent and predictable pharmacokinetics and pharmacodynamics across a wide range of patient populations allow administration with fixed dosing and with no coagulation monitoring. In 4 orthopaedic surgery clinical trials (12,700 patients), 10mg postoperative (6-10 hours after the end of surgery) dose, once daily, of oral rivaroxaban, achieved superior efficacy and similar safety to enoxaparin, whatever the dose of enoxaparin. Indeed, 40 mg once a day in Europe and 30 mg bid in US of enoxaparin were compared to the same dose of 10mg once daily of rivaroxaban. Furthermore, there is no difference according to liver enzymes elevation and cardio-vascular adverse events. Although the risk of spinal haematoma after neuraxial anaesthesia is rare, it is increased by concomitant use of anticoagulants. In orthopedic surgery trials with rivaroxaban to date, complications such as spinal haematoma have not been reported. The pharmacokinetic profile of rivaroxaban suggests that concurrent use with neuraxial anaesthesia should require no further precautions than currently necessary with low-molecular-weight heparin.