Elastase levels in salvaged blood and the effect of cell washing

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.

An economic analysis of costs associated with development of a cell salvage program

BACKGROUND

The increasing cost of blood products and associated risks of transfusion have lead to a heightened interest in techniques which reduce or replace allogeneic blood transfusion. The use of cell salvage is being explored in a number of institutions. We present financial information which may be useful to institutions that are considering the addition of a cell salvage service.

METHODS

A review of the cell salvage data from 2328 patients was used to estimate the average cost of a packed red blood cell unit equivalent processed by cell salvage equipment. In addition, an analysis was performed to assess the break-even point of establishing a cell salvage service.

RESULTS

Initial capital outlay to establish a cell salvage service at this institution was $103,551. The annual fixed operating cost was $250,943. The average cost of transfusion of an allogeneic packed red blood cell unit was $200. For an equivalent cell salvage unit, the cost was $89.46. The payback period was 1.9 mo.

CONCLUSION

This analysis suggests that cell salvage can be significantly less expensive than allogeneic blood. The cost of cell salvage in other institutions will vary depending upon case volume, expected levels of blood loss per case, and initial investment costs. A step-by-step formula is provided to assist in the evaluation of a cell salvage service in hospitals of various sizes.

Greater increase in cytokine concentration after salvage with filtered whole blood than with washed red cells, but no difference in postoperative hemoglobin recovery

BACKGROUND

Inflammatory mediators are released in association with intraoperative and postoperative salvage of blood. Whether these mediators (cytokines) participate in the modulation of erythropoiesis or not has been investigated.

STUDY DESIGN AND METHODS

Twenty-seven patients who were to undergo total knee replacement surgery were randomly assigned to postoperative blood salvage with either filtered whole blood or washed red cells. Patients with postoperative blood loss <400 mL were considered a control group. The control group did not receive any transfusions. Plasma concentrations of the anaphylatoxin C3a, the C5b-9 terminal complement complex, and the cytokines interleukins 6 and 8, hemoglobin, reticulocytes, and red cell volume fraction in the patients were repeatedly analyzed before and after surgery.

RESULTS

Significantly increased concentrations of interleukin 6 appeared in all three groups, which was interpreted as a response to the surgical trauma. The increase was significantly greater in the group that received filtered whole blood after return of shed blood. The recovery of hemoglobin levels did not differ in the groups.

CONCLUSION

The transfusion of filtered whole blood leads to the formation of interleukin 6 in the circulation, but postoperative hemoglobin recovery was similar in all groups.

Formation of complement split products and proinflammatory cytokines by reinfusion of shed autologous blood

1. The purpose of this study was to determine whether shed autologous blood collected postoperatively contains complement split products (C3a and SC5b-9) and proinflammatory cytokines (TNF-alpha, IL-1beta, IL-6 and IL-8) and whether transfusion of shed blood increases the concentrations of inflammatory mediators in the circulation. 2. Twenty consecutive patients undergoing total hip replacement surgery under spinal anaesthesia were studied. The patients were transfused with whole blood collected postoperatively. 3. The median volume shed blood returned to the patients was 350 ml (25-75% range = 300-450). Before transfusion of shed blood was filtered using a 40 microm filter (Solcotrans). Samples for complement and cytokine determinations were drawn from the collected blood. 4. Venous blood samples were drawn 1 min before transfusion, 1 and 60 min after completed transfusion. High concentrations of C3a, SC5b-9, TNF-alpha, IL-1beta, IL-6 and IL-8 were found in shed blood. The concentrations were higher than the circulating levels (P < 0.05). The filtration procedure did not significantly reduce the concentrations. 5. Transfusion of the shed blood did not significantly alter the circulating concentrations of C3a, SC5b-9, TNF-alpha, IL-1beta, and IL-8. The plasma concentrations of IL-6 were increased both 1 and 60 min after completed transfusion compared to before (P < 0.05). 6. This study shows that whole blood collected from a surgical wound contains large concentrations of complement split products and proinflammatory cytokines. Transfusion of shed blood leads to elevated plasma levels of IL-6.

Removal of activated complement from shed blood: comparison of high- and low-dilutional haemofiltration

BACKGROUND

Perioperative blood salvage is associated with release of inflammatory mediators. Depending on type of processing, the complement system is activated to some extent in the final blood product. The aim of the present study was to evaluate a haemofiltration technique concerning complement system activation and whether the volume of added saline will have an influence on the elimination of activated complement during processing.

METHODS

Sixteen patients undergoing total hip arthroplasty received wound blood salvaged intraoperatively with a haemofiltration technique. Saline was added to the reservoir for washing in a ratio of 1:1 or 5:1 of estimated blood volume. Samples for determination of the anaphylatoxins C3a and C5a, and the terminal SC5b-9 complement complex (TCC) were drawn from the patients, the collected blood, the ultrafiltrate and the processed blood.

RESULTS

Increased concentrations of C3a, C5a and TCC were found in aspirated and processed blood. Haemofiltration did not reduce the concentrations of these factors, except that of C3a in the group where saline was added in a ratio of 5:1. There were no increased concentrations of C3a, C5a or TCC in the patient plasma after reinfusion. No differences in blood pressure, heart rate, pH, arterial oxygen tension, arterial carbon dioxide tension, or base excess were found in association with reinfusion of the blood.

CONCLUSION

Collected shed blood washed through haemofiltration contained moderately elevated concentrations of C3a, C5a and TCC. Reinfusion of the blood neither led to increased systemic concentrations of complement activation products, nor to disturbances in haemodynamic or biochemical parameters.

Release of inflammatory mediators in association with collection of wound drainage blood during orthopaedic surgery

Ten patients undergoing hip replacement surgery were studied regarding activation of complement and leukocytes in association with collection of wound drainage blood. The blood was collected postoperatively but not reinfused due to the possible risks with reinfusion of blood containing inflammatory mediators. Blood samples for analysis of complement activation (TCC), leukocyte activation (PMN elastase) and cytokines (Interleukin-6) were drawn preoperatively from the patients. Blood samples were also drawn intraoperatively from the wound. Samples were also drawn from the collected wound drainage blood, before and after blood was passed through a microporous filter. There were elevated concentrations of TCC, PMN elastase and IL-6 in the collected wound drainage blood before and after the filter. The filtration did not significantly reduce the concentrations of these factors. In the wound blood the concentrations were higher compared to those found in the systemic blood preoperatively, but lower compared to concentrations found in the collected drainage blood. The study demonstrates that the collection of wound drainage whole blood is associated with activation of complement, release of PMN elastase and cytokines.

Release of cytokines, polymorphonuclear elastase and terminal C5b-9 complement complex by infusion of wound drainage blood

25 patients undergoing total hip replacement surgery were studied in an investigation of release of cytokines (interleukin-1 beta, IL-1 beta; interleukin-6, IL-6; interleukin-8, IL-8; and tumor necrosis factor-alpha, TNF-alpha), PMN elastase and terminal C5b-9 complement complexes (TCC) at the time of collection and transfusion of autologous blood. 15 patients received wound blood that was washed and centrifuged before being transfused as an erythrocyte suspension. In this blood there were no elevations in the concentrations of cytokines, TNF-alpha, PMN elastase or TCC, and there was no increase in these variables in plasma after transfusion of wound blood. 10 patients received postoperatively-collected drainage blood. There were high amounts of cytokines, PMN elastase and TCC in this blood, and filtration of the collected drainage blood did not reduce the concentrations of these factors, except those of TCC. When the collected drainage blood was infused, elevated plasma concentrations of IL-6, IL-8 and PMN elastase were observed 1 and 60 minutes after completing the transfusion. No differences regarding blood pressure, oxygen saturation (SpO2), and hemoglobin concentration between the groups were recorded.

Plasma levels of the lipid mediators, leukotriene B4 and lyso platelet-activating factor, in intraoperative salvaged blood

It has been shown that white cells and platelets release their granules into the plasma of salvaged blood. Whether this release is due to destruction alone or a combination of destruction and activation is not known. Lipid mediators, platelet-activating factor and leukotriene B4, are produced by activated white cells and platelets and have effects on the cardiovascular, respiratory and immune systems and the microcirculation. The aim was to determine if white cells and platelets are activated in salvaged blood by measuring the levels of these lipid mediators. Ten patients undergoing aortic surgery, where intraoperative salvage was used, were studied. Blood samples were taken from the patient's circulation and the salvaged blood before and after washing. The levels of leukotriene (LTB4) and lyso platelet-activating factor (PAF, the stable degradation product of PAF) were measured in the samples by a radioimmunoassay and a bioassay, respectively. The levels of both these substances increased in the unwashed salvaged blood (mean patient levels: LTB4 27 +/- 4.3 ng/ml and L-PAF 73 +/- 8.5 ng/ml; mean unwashed blood levels: LTB4 95 +/- 12.2 ng/ml and L-PAF 172.9 +/- 26.4 ng/ml) and were reduced by washing of the collected blood (mean washed blood levels of LTB4, 23.9 +/- 4.8 ng/ml, and L-PAF 18 +/- 5 ng/ml). The increase of the lipid mediators in the unwashed salvaged blood indicates that white cells and platelets are activated and releasing lipid mediators. Washing of the collected blood is effective in removing the lipid mediators.

Use of the cell saver during elective abdominal aortic aneurysm surgery--influence on transfusion with bank blood. A retrospective survey

One hundred and two patients undergoing elective abdominal aortic aneurysm repair and admitted to ICU at RPAH in 1989/90 were studied. In forty patients a cell saver was used during the operative procedure (Group CS) while in the remaining sixty-two patients intraoperative blood loss was drained and discarded conventionally (Group NCS). Preoperative ASA grade and postoperative APACHE score were similar in these two groups. The amount of bank blood transfused intraoperatively was less in Group CS than in Group NCS (0.6 +/- 0.2 vs 3.3 +/- 0.3 units) (mean +/- SEM) (P less than 0.0001). The total amount of bank blood transfused during hospital admission was also less in Group CS (1.5 +/- 0.4 vs 4.8 +/- 0.4 units, P less than 0.0001). Of Group CS, 22 patients (55%) received no bank blood compared to two patients (3%) in Group NCS. There was no difference between the groups with respect to postoperative haemoglobin and creatinine levels. ICU stay was similar in both groups. We conclude that use of the cell saver reduces perioperative bank blood transfusion in elective abdominal aortic surgery.

Calprotectin (the L1 protein) during surgery in patients with rheumatoid arthritis

Calprotectin (L1) is a major leukocyte protein which is released during activation or death of neutrophil granulocytes and monocytes. Previous studies have shown that L1 may be a useful marker of disease activity in patients with adult or juvenile rheumatoid arthritis (RA). In the present study, the plasma concentrations of L1 were analysed during shoulder-joint surgery in 16 patients with adult or juvenile RA. Decreased L1 concentrations were found 48 h postoperatively. Thereafter, the L1 concentrations were increased at 72 h, with a following decrease until day 14 postoperatively. In contrast, increased serum concentrations of both C-reactive protein (CRP) and orosomucoid (i.e. alpha 1-acid glycoprotein) were found at 48 h after surgery. Plasma samples obtained before and after surgery were analysed by gel filtration. Approximately 3/4 of the plasma L1 was found in fractions corresponding to the native molecule, while the rest was detected in higher molecular mass fractions. The distribution of L1 antigen in low and high molecular mass regions did not differ between the pre- and postoperative plasma samples. The L1 protein consists of light and heavy chains. Increased serum levels of the cystic fibrosis antigen, which is identical to L1 light chain, have been described in patients with cystic fibrosis. The existence of circulating free L1 chains was presently investigated in plasma obtained before and after surgery. After gel filtration of plasma samples, no free L1 chains were detected by use of enzyme immunoassay and dot blot.