Teeztmann et al. conducted a randomised controlled study where 164 patients received either autologous salvaged blood collected using the Sangvia™ Blood Salvage System or allogeneic red cell concentrates if transfusion was indicated according to clinical judgment (there were not predefined transfusion criteria).
No statistically significant difference in postoperative infection rate (primary outcome variable) was observed between the two groups (2.7% vs. 3.4%, P = NS), but the study was clearly not powered to detect such a difference. Using data from more than 12,000 patients assessed in the Phase III rivaroxaban (RECORD) studies, Friedman et al. found that the rate of any infection was 9.9% in patients receiving allogeneic blood transfusion and 7.9% in patients not receiving allogeneic blood transfusion with or without autologous blood transfusion (P = 0.003) [1]. Using these infection rates, the inclusion of at least 3000 patients per study harm would have been needed to detect a difference of at least 20% between groups.
As for the secondary endpoints of the study, the authors noted that the observed increase in C-reactive protein concentrations (close to statistical significance) indicate that autologous blood transfusions stimulate the patient’s immune system. The reversion of post-traumatic immune suppression following total knee arthroplasty by reinfusion of ACD-anticoagulated postoperative shed blood was recently demonstrated by Islam et al., who measured an extensive set of biomarkers of sterile trauma including haematological values, damage-associated molecular patterns (DAMPs), cytokines and chemokines [2]. However, the authors suggested that over 1000 patients would be needed to demonstrate a reduction in postoperative infections [2].
Teeztmann et al. also found that transfusion of autologous blood did not reduce the use of allogeneic red cell concentrates ‒ a finding that is in line with previous observations by Thomassen et al. [3] and Horstmann et al. [4, 5]. However, transfusion rates in the study by Teeztmann et al. were higher, most probably due to the lack of optimisation of preoperative haemoglobin in those presenting with low levels (range, 9 to 17 g/dL) and a liberal transfusion policy (transfusion index: ~2.5 U/transfused patient). As in previous studies, the autologous blood collection technique appears to be safe.
Finally, the highly significant inverse correlation between preoperative haemoglobin concentration and transfusion of allogeneic blood observed in this study is in agreement with previous observations and reinforces the need for preoperative haemoglobin optimisation in this patient population.
In conclusion, the available published evidence does not support the routine use of the Sangvia device in elective hip replacement surgery.
– Manuel Muñoz
References
1. Friedman R, Homering M, Holberg G, Berkowitz SD. Allogeneic blood transfusions and postoperative infections after total hip or knee arthroplasty. J Bone Joint Surg Am 2014;96:272-8.
2. Islam N, Whitehouse M, Mehendale S, et al. Post-traumatic immunosuppression is reversed by anti-coagulated salvaged blood transfusion: deductions from studying immune status after knee arthroplasty. Clin Exp Immunol 2014;177:509-20.
3. Thomassen BJ, Pilot P, Scholtes VA et al. Limit allogeneic blood use with routine re-use of patient’s own blood: a prospective, randomized, controlled trial in total hip surgery. PLoS One 2012;7(9):e44503.
4. Horstmann WG, Swierstra MJ, Ohanis D, Castelein RM, Kollen BJ, Verheyen CC. Reduction of blood loss with the use of a new combined intra-operative and post-operative autologous blood transfusion system compared with no drainage in primary total hip replacement. Bone Joint J 2013;95-B:616-22.
5. Horstmann WG, Swierstra MJ, Ohanis D, Rolink R, Kollen BJ, Verheyen CC. Favourable results of a new intraoperative and postoperative filtered autologous blood re-transfusion system in total hip arthroplasty: a randomised controlled trial. Int Orthop 2014;38:13-8.
