[Thromboelastometric profile of unwashed shed blood after primary knee arthroplasty]

INTRODUCTION

Knee arthroplasty causes significant blood loss. Different blood-saving measures exist like retransfusion of unwashed salvaged blood. Some studies question the quality of this blood and in particular its ability to clot. These studies use "static" coagulation tests reflecting only partially the reality, unlike viscoelastic methods. The main objective of this study was to evaluate the salvaged blood thromboelastometric profile using ROTEM® system and to compare these results with patient venous blood.

MATERIALS AND METHODS

We performed an observational, prospective, single-center study conducted over 3 months in 2013. Agreement of local ethical committee and patient consent were obtained beforehand. All adult patients who underwent a primary total knee arthroplasty were included. A thromboelastometric profile and standard laboratory tests (hemoglobin, platelets count, PT, aPTT, fibrinogen) were performed in the same time on patient venous blood and on unwashed salvaged blood in the PACU.

RESULTS

Twenty patients were included. The median duration of surgery was 93 minutes. Thirteen patients (65%) received tranexamic acid during procedure. The median volume of shed blood was 225 mL. Two patients (10%) received a reinfusion. Analysis of shed blood showed a major deficiency of clotting factor in standard biology (PT<10%) and an absence of clot formation in thromboelastometric test (In-tem®, Ex-tem®, Fib-tem® or Ap-tem®). Compared to venous blood, shed blood had significantly lower hemoglobin levels: 8.8 vs 13.5 g/dL (P<0.0001). Allogenic transfusion concerned 5% of patients.

DISCUSSION

In this work, we confirmed that shed blood was naturally uncoagulable probably due to a multifactorial mechanism involving a major clot factor deficiency and an activation of fibrinolysis.

[The different types of therapeutic plasma are equivalent?]

In France, three varieties of therapeutic plasma are being processed, distributed and delivered, currently; however, many more varieties are in use worldwide, which go by the property of labile blood component or plasma derived medicines. For one type of component (one given name), several devices and bags and so on are used to concur to its process, which makes that one type of therapeutic plasma may significantly differ from one production setting to one other. This may affect (more or less) the component properties as well as the possibly reported adverse events. This review aims thus, firstly at stressing on the difficulty in comparing data obtained in different contexts, and secondly at making the point on future directions to process therapeutic plasma.

[Off-label use of recombinant factor VII (rFVIIa) in teaching hospitals in Paris in 2010]

INTRODUCTION

Recombinant activated factor VII (rFVIIa) (Novoseven(®)) was initially developed as a substitutive treatment in haemophiliacs but has then been used in situations of major haemorrhage in non-haemophiliacs (off-label use). The goal of the present study was to assess the practice patterns when rFVIIa is used in off-label indications in major teaching hospitals of Paris in 2010.

METHODS

We retrospectively identified files of patients in whom rFVIIa had been used. Physicians in charge of these patients (or the most proxy physician available) were contacted and files analysed with one of the authors. Quality of rFVIIa used in these off-label situations was determined based on either French or European guidelines or the available literature when no guidelines could be found. Three categories were defined for indication, dosage, timing, associated biological factors and overall use: adequate, acceptable (mainly adequate but lacking some characteristics of an "ideal" prescription) and inadequate (lacking most of the necessary characteristics of an "ideal" prescription).

RESULTS

Among 59 patients who had an off-label prescription of rFVIIa, 49 prescriptions could be analysed. Indication for use and timing of administration were adequate in 100% of multiple trauma cases and 83% of obstetrical cases. Biological criteria associated with an improved efficacy were found in two thirds of prescriptions analysed. Overall, prescriptions were adequate or acceptable in 82% of cases.

CONCLUSION

In the vast majority of patients who received rFVIIa for off-label indications in teaching hospitals of the Paris area in 2010, prescriptions were in line with recommendations.