Activation of plasma coagulation by retransfusion of unwashed drainage blood after hip joint arthroplasty: a prospective study

Cell salvage in trauma

PURPOSE OF REVIEW

The collection of shed blood and its reinfusion has been termed 'cell salvage' or 'autotransfusion'. This review will summarize the historical foundation of cell salvage and summarize recent literature associated with cell salvage use in trauma.

RECENT FINDINGS

There have been no publications on cell salvage in trauma during the last 2 years. This is based on a PubMed search using the key words, 'cell salvage', 'autologous blood transfusion' and 'operative blood salvage'. Although the wars in Iraq and Afghanistan were ongoing, publications focused upon autotranfusion of unwashed blood from the hemothorax and on the resuscitation of the injured in remote settings.

SUMMARY

Autotransfusion or cell salvage is markedly under utilized in trauma. Opportunities exist for significant blood savings if it is used more frequently. More research is clearly needed to assess the safety of autotransfusion in the traumatized patient.

Traumatic Hemothorax Blood Contains Elevated Levels of Microparticles that are Prothrombotic but Inhibit Platelet Aggregation

OBJECTIVES

Autotransfusion of shed blood from traumatic hemothorax is an attractive option for resuscitation of trauma patients in austere environments. However, previous analyses revealed that shed hemothorax (HX) blood is defibrinated, thrombocytopenic, and contains elevated levels of D-dimer. Mixing studies with normal pooled plasma demonstrated hypercoagulability, evoking concern for potentiation of acute traumatic coagulopathy. We hypothesized that induction of coagulopathic changes by shed HX blood may be due to increases in cellular microparticles (MP) and that these may also affect recipient platelet function.

METHODS

Shed HX blood was obtained from 17 adult trauma patients under an Institutional Review Board approved prospective observational protocol. Blood samples were collected every hour up to 4 h after thoracostomy tube placement. The corresponding plasma was isolated and frozen for analysis. The effects of shed HX frozen plasma (HFP) and isolated HX microparticles (HMP) on coagulation and platelet function were assessed through mixing studies with platelet-rich plasma at various dilutions followed by analysis with thromboelastometry (ROTEM), platelet aggregometry (Multiplate), enzyme-linked immunosorbent assays, and flow cytometry. Furthermore, HFP was assessed for von Willebrand factor antigen levels and multimer content, and plasma-free hemoglobin.

RESULTS

ROTEM analysis demonstrated that diluted HFP and isolated HMP samples decreased clotting time, clotting formation time, and increased α angle, irrespective of sample concentrations, when compared with diluted control plasma. Isolated HMP inhibited platelet aggregation in response to adenosine diphosphate, arachidonic acid, and collagen. HFP contained elevated levels of fibrin-degradation products and tissue factor compared with control fresh frozen plasma samples. MP concentrations in HFP were significantly increased and enriched in events positive for phosphatidylserine, tissue factor, CD235, CD45, CD41a, and CD14. von Willebrand factor (vWF) multimer analysis revealed significant loss of high molecular weight multimers in HFP samples. Plasma-free hemoglobin levels were 8-fold higher in HFP compared with fresh frozen plasma.

CONCLUSION

HFP induces plasma hypercoagulability that is likely related to increased tissue factor and phosphatidylserine expression originating from cell-derived MP. In contrast, platelet dysfunction is induced by HMP, potentially aggravated by depletion of high molecular weight multimers of vWF. Thus, autologous transfusion of shed traumatic hemothorax blood may induce a range of undesirable effects in patients with acute traumatic coagulopathy.

Washed cell salvage in surgical patients: A review and meta-analysis of prospective randomized trials under PRISMA

BACKGROUND

Cell salvage is commonly used as part of a blood conservation strategy. However concerns among clinicians exist about the efficacy of transfusion of washed cell salvage.

METHODS

We performed a meta-analysis of randomized controlled trials in which patients, scheduled for all types of surgery, were randomized to washed cell salvage or to a control group with no cell salvage. Data were independently extracted, risk ratio (RR), and weighted mean differences (WMD) with 95% confidence intervals (CIs) were calculated. Data were pooled using a random effects model. The primary endpoint was the number of patients exposed to allogeneic red blood cell (RBC) transfusion.

RESULTS

Out of 1140 search results, a total of 47 trials were included. Overall, the use of washed cell salvage reduced the rate of exposure to allogeneic RBC transfusion by a relative 39% (RR = 0.61; 95% CI 0.57 to 0.65; P < 0.001), resulting in an average saving of 0.20 units of allogeneic RBC per patient (weighted mean differences [WMD] = -0.20; 95% CI -0.22 to -0.18; P < 0.001), reduced risk of infection by 28% (RR = 0.72; 95% CI 0.54 to 0.97; P = 0.03), reduced length of hospital stay by 2.31 days (WMD = -2.31; 95% CI -2.50 to -2.11; P < 0.001), but did not significantly affect risk of mortality (RR = 0.92; 95% CI 0.63 to 1.34; P = 0.66). No statistical difference could be observed in the number of patients exposed to re-operation, plasma, platelets, or rate of myocardial infarction and stroke.

CONCLUSIONS

Washed cell salvage is efficacious in reducing the need for allogeneic RBC transfusion and risk of infection in surgery.

Efficacy and safety using autotransfusion system with postoperative shed blood following total knee arthroplasty in haemophilia

The purpose of this study was to evaluate the efficacy and safety of postoperative wound drain salvage and autotransfusion system in haemophilic patients undergoing elective total knee arthroplasty (TKA). No literature exists on reinfusing drained blood in patient with haemophilia undergoing TKA. Eighty-eight knees of 66 patients received cemented TKA due to end-stage haemophilic arthropathy (group I; with autotransfusion in 59 knees, group II; without autotransfusion in 29 knees). In group I, the postoperative shed blood was transfused within 6 h after surgery. The amount of blood drainage and reinfused blood, rate and amount of allogenic transfusion, postoperative change of haemoglobin level, prothrombin time (PT) and activated partial thromboplastin time were analysed. The mean postoperative blood drainage was 932 ± 479 mL in group I and 830 ± 492 mL in group II (P > 0.05). The mean volume of blood reinfused was 530 ± 265 mL in group I. Allogenic transfusion was needed in six knees (10.2%) of group I and eight knees (27.6%) of group II (P = 0.036). The mean volume of allogenic transfusion was 480 ± 49 mL in group I and 1041 ± 691 mL in group II (P > 0.05). Changes of all the laboratory results before and after TKA showed no statistically significant difference except PT was prolonged in group I (P = 0.008) at postoperative day 1. Moreover, there was no significant complication related to either reinfusion or allogenic transfusion in both groups. This study showed that reinfusion of drained blood is a simple, safe and efficacious method in patients with haemophilia undergoing TKA.

The effect of salvaged blood on coagulation function as measured by thromboelastography

BACKGROUND

There is concern that salvaged blood has the potential to activate the coagulation system, which might place patients at risk of thrombotic complications. The aim of this study was to determine whether transfusion of salvaged blood after total knee arthroplasty (TKA) would lead to procoagulopathic changes as measured by thromboelastography (TEG) and furthermore if washing would reduce this risk.

STUDY DESIGN AND METHODS

Twenty-two patients undergoing TKA were enrolled. Control samples were venous blood samples taken before surgery. Test samples were created by mixing the control samples with postoperatively salvaged blood, either washed or unwashed. TEG profiles were measured, noting the time to initiate clotting (R), the time of clot formation (K), the angle of clot formation (α-angle), and the maximum amplitude (clot strength [MA]).

RESULTS

The changes in the coagulation profile from control samples to test samples were consistent for both the washed and the unwashed groups: R time decreased, MA decreased, and K and α-angle remained the same. However, the changes were more pronounced in the unwashed group than the washed group, with a 61% decrease in R time compared with 14%, and a 26% decrease in MA compared with 6%.

CONCLUSION

The addition of salvaged blood to the patient's preoperative blood resulted in decreased MA as well as decreased R time. This suggests that the reinfusion of postoperatively salvaged washed or unwashed blood after TKA favors a change toward a more hypocoagulable state, and washing appears to reduce this effect.

Washing and filtering of cell-salvaged blood - does it make autotransfusion safer?

Autologous transfusion was first performed in the late 1800s, but it was not until the 1970s that devices were developed that enabled widespread adoption of the practice. Unwashed salvaged blood contains thrombogenic products, cell breakdown products and plasma proteins, and gross chemical, cellular and physical contaminants. Washing and filtering of salvaged blood is routinely performed to remove or reduce these elements. In this paper we review the clinical data supporting the need for washing and filtering of salvaged blood.

Transfusion of intra-operative autologous whole blood: influence on complement activation and interleukin formation

BACKGROUND AND OBJECTIVES

Transfusion of autologous whole blood is one available method to reduce the need for allogenic blood transfusion. The objective of this study was to investigate the safety of transfusion of intra-operative autologous whole blood by monitoring plasma concentration of laboratory variables and adverse events after transfusion with the Sangvia(®) system.

MATERIALS AND METHODS

The clinical trial was designed as an open, prospective, multi-centre study, and a total of 20 patients undergoing primary hip arthroplasty were included. Systemic blood samples were taken and analysed preoperatively, at transfusion start and end and at 3, 6, 24 and 48 h after the transfusion.

RESULTS

Elevated values of complement activation and pro-inflammatory cytokines were seen in the intra-operatively collected blood but the impact on systemic levels were limited with low peak levels, systemic elevations before transfusion and normalization during the study period. Elevated levels of free haemoglobin and potassium were also detected in the intra-operatively collected blood, but systemic values were within reference values after the transfusion. No clinically relevant adverse event occurred during the study.

CONCLUSION

Inflammatory mediators and plasma haemoglobin were increased in intra-operatively salvaged and filtered blood compared to circulatory levels. Intra-operative retransfusion of autologous whole blood caused a transient systemic increase that normalized in the early postoperative period. There were no significant adverse events reported in the study. These data suggest that the Sangvia(®) system can be used for intra-operative collection and retransfusion of salvaged blood.

The perioperative von Willebrand factor activity and factor VIII levels among alcohol use disorder patients undergoing total knee or hip replacement

Alcohol use disorder patients have a five-fold higher risk of postoperative bleeding complications. We measured the perioperative von Willebrand factor and factor VIII levels in consecutive patients with alcohol use disorder. In one university hospital, 105 patients scheduled for arthroplasty were screened, and 25 fulfilled inclusion criteria. Postoperatively, we found significantly decreased von Willebrand factor ristocetin cofactor values over time among alcohol use disorder patients and significantly different time courses of factor VIII levels between patients with and without a diagnosed alcohol use disorder. Blood loss was significantly increased among alcohol use disorder patients on their first postoperative day.

The future of blood management

An evolving understanding of the consequences of allogeneic blood transfusion and escalating costs of providing allogeneic blood have resulted in an interest in blood management. Understanding the consequences of allogeneic transfusion includes a recognition of the immunosuppressive effects of allogeneic transfusion, a growing awareness of transfusion-related acute lung injury, and a rediscovery of transfusion-associated circulatory overload. More recently, interest has focused on the effect of stored blood on patient outcome. Although this discussion is not all-inclusive, it is intended to show that many techniques can be applied to decrease the exposure to allogeneic blood.

Complement split products and proinflammatory cytokines in intraoperatively salvaged unwashed blood during hip replacement: comparison between heparin-coated and non-heparin-coated autotransfusion systems

BACKGROUND AND OBJECTIVES

The aim of the present study was to investigate the quality of shed blood collected in a new intraoperative autotransfusion system (Sangvia, AstraTech, Sweden) and to study whether heparin-coated surfaces in the device reduce the production of inflammatory mediators.

MATERIAL AND METHODS

The study was randomized and prospective. Twelve total hip arthroplasty patients whose blood was collected with a device having a heparin-coated surface and 12 patients whose blood was collected with a device having a non-heparin-coated surface were included. Venous blood was drawn from the patients preoperatively. Intraoperatively 200 ml salvaged blood was collected and samples were also withdrawn; samples were obtained from the blood bag.

RESULTS

Compared to venous blood, elevated concentrations of interleukin 6 (IL-6), IL-8, C3a and polymorphonuclear elastase were found in collected blood. No significant differences in inflammatory mediators were found between the heparin-coated and the non-heparin-coated groups. The median haemoglobin concentration in the salvaged blood was 74 g/l in both groups. Plasma haemoglobin and potassium concentrations were also elevated. There were no significant differences between the groups.

CONCLUSION

The present study indicates that the blood salvaged intraoperatively contains elevated levels of complement split product and proinflammatory cytokines and that heparin-coated surfaces of the salvage device do not significantly influence the formation of inflammatory mediators.

Platelet and leukocyte activation in salvaged blood and the effect of its reinfusion on the circulating blood

Postoperative wound drainage reinfusion reduces the frequency of homologous blood transfusion. The salvaged blood is depleted of coagulation factors but may contain platelets and leukocytes which are activated, and therefore potentially procoagulant. We ascertained the degree of activation of platelets and leukocytes in salvaged blood and asked whether their infusion produced any measurable effect on patients' coagulation system. We prospectively randomized 24 patients who had total knee arthroplasties to reinfusion of salvaged autologous blood (n = 12) or a standard drain with no reinfusion (n = 12). Analysis of the salvaged blood showed marked activation of platelets as shown by their expression of P-selectin, CD40 ligand, and Factor V/Va, and as increased numbers of platelet-derived microparticles. After reinfusion there was no measurable effect on activation markers of circulating platelets or leukocytes but there was a decrease in platelet count in the reinfused group compared with the control group. Levels of prothrombin fragment F1 + 2 (suggesting thrombin formation) increased in the reinfused group compared with control group, possibly indicating activation of coagulation systemically. The platelets and leukocytes in salvaged blood are markedly activated and their reinfusion causes a decrease in platelet count in the recipient and a possible increase in thrombin generation potentially favoring thrombosis.

Activation of the complement system by different autologous transfusion devices: an in vitro study

BACKGROUND

The aim of the present investigation was to study whether autologous transfusion devices activate the complement system and whether complement-activated blood is more vulnerable to further activation during processing.

STUDY DESIGN AND METHODS

Forty-eight blood units were randomized to be processed by one of three different salvage systems: Group 1 underwent whole blood filtration (hemofiltration) (n=16); Group 2 underwent continuous processing, saline washing, and centrifugation (CATS, Fresenius AG ) (n=16); and Group 3 underwent saline washing and centrifugation (Cell-Saver, Haemonetics Corp.) (n=16). Eight blood units for each system were activated with cobra venom factor (CVF) at a concentration of 0.2 U per mL whole blood before processing. C activation was studied by determinations of C4d, Bb, C3a, and SC5b-9. Samples were drawn from whole blood, processed blood, and the waste bags.

RESULTS

The concentrations of Bb, C3a, and SC5b-9 in whole blood after activation with CVF were significantly elevated compared to blood that was not activated (p < 0.01). Processed blood from hemofiltration contained significantly higher levels of complement-split products than techniques that use washing and centrifugation. The concentrations of SC5b-9 in blood processed by hemofiltration were higher in the experiments with CVF activation (p < 0.05).

CONCLUSION

The tested autologous transfusion systems did not themselves activate the complement system, and complement-activated blood was not more vulnerable to further activation during processing. A blood-salvaging technique that used washing and centrifugation reduced elevated concentrations of complement-split products, whereas hemofiltration did not.