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

Cell saver blood transfusions may be associated with a decrease in inflammation and improved outcome measures in pediatric cardiac surgery patients

OBJECTIVE

Cardiopulmonary bypass (CPB) is a requisite for correction of congenital heart disease by open-heart surgery and induces a systemic inflammatory response that can lead to complications such as acute lung injury and acute kidney injury. In addition, blood transfusions are commonly required for this type of surgery, and they may further exacerbate this inflammatory response and increase morbidity and mortality. We hypothesized that, in contrast to red blood cells, intraoperative cell saver (CS) blood transfusions attenuate the post-CPB proinflammatory cytokine response.

METHODS

Serum cytokine concentrations of IL-10, IL-1RA, IL-6, IL-8, and TNF-α were measured at four time points (preoperatively and postoperatively on postoperative days 0, 1, and 2).

RESULTS

Anti-inflammatory IL-10 levels were significantly lower in the CS group on POD 0 than in the control group (mean 1083.2 pg/mL vs 2080.2 pg/mL, 95%CI 357.4-1636.6, p = .0026). Of the clinical parameters measured, mean BUN and creatinine levels on POD 2 were significantly lower in the CS group (13.79 vs 21.88, p = .004 and 0.45 vs 0.55, p = .055, respectively). In addition, the duration of milrinone use decreased by 80% in the CS group (0.20, 95%CI 0.04, 0.94; p = .048), the median time to extubation in hours was significantly lower in the CS group (3.5 vs 6.5; 95%CI -38.00, -0.50; p = .026), and hospital length of stay was decreased by 60% in the CS group (p = .003).

CONCLUSIONS

CS transfusions in children may lower postoperative anti-inflammatory IL-10 levels, possibly due to an overall decrease in proinflammatory state, and may be associated with improvements in renal and pulmonary functions.

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.

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.

Is cell salvage safe in liver resection? A pilot study

STUDY OBJECTIVE

To investigate the quality of cell salvaged (CS) blood in patients undergoing hemihepatectomy (study group) and compare it with CS-blood from aortic surgery (control group).

DESIGN

Observational study.

SETTING

Operating room in a university hospital.

MEASUREMENTS

6 patients undergoing hemihepatectomy or aortobifemoral bypass with intraoperative blood loss of more than 800 mL. Samples were drawn from the central venous catheter, from the reservoir of a CS recovery system, and from the processed blood in each patient to determine interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor (TNF), complement C3a, and the terminal complement complex C5b-9. Microbiological analysis included colony count after cultivation in aerobic and anaerobic medium as well as enrichment culture for 6 days.

MAIN RESULTS

In the hemihepatectomy group, levels of IL-6, C3a, and C5b-9 were significantly higher in the reservoir than in samples obtained from the central venous catheter. After the washing procedure, levels of IL-6, C3a, and C5b-9 were lower in the liver resection group than in each patient's own plasma levels. In all patients undergoing aortobifemoral bypass and in 5 patients undergoing hemihepatectomy, blood samples were sterile or showed growth of commensal skin microflora in low numbers (coagulase-negative staphylococci or propionibacteria). In one patient in the liver resection group, we could not exclude contamination with intestinal flora.

CONCLUSION

Cell salvaged blood in liver resection seems to be safe for retransfusion with respect to cytokine release and complement activation, but requires further investigation in regard to bacterial contamination.

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.

Efficacy and economics of postoperative blood salvage in patients undergoing elective total hip replacement

INTRODUCTION

Patients undergoing total hip replacement (THR) regularly receive allogenic blood transfusions. The infusion of allogenic blood exposes the recipient to significant risks including the transmission of infection, anaphylactic and haemolytic reactions. The purpose of this study was to determine the effect of introducing a system to retransfuse salvaged drainage blood in patients undergoing primary THR.

PATIENTS AND METHODS

We reviewed records of 109 consecutive patients who underwent THR following the introduction of the ABTrans autologous retransfusion system at our institution in January 2000. For comparison, we reviewed the medical records of 109 patients who underwent the same procedure immediately before the introduction of the retransfusion system.

RESULTS

Overall, 9% of patients treated with blood salvage and 30% treated without blood salvage required allogenic blood transfusions. Patients treated with the salvage system had significantly smaller haemoglobin drops in the peri-operative period (difference 0.56 g/dl; P = 0.001). The overall cost of using the retransfusion system was similar to that of routine vacuum drainage when the savings of reduced allogenic blood transfusion were taken into account.

CONCLUSIONS

The retransfusion of postoperative drainage blood is a simple, effective and safe way of providing autologous blood for patients undergoing primary THR.

Cell Salvage Alters the Systemic Inflammatory Response After Off-Pump Coronary Artery Bypass Grafting Surgery

BACKGROUND

Retransfused cardiotomy suction blood contains elevated inflammatory markers and is a bypass independent source of inflammatory mediators. We hypothesized that, during off-pump coronary artery bypass (OPCAB) grafting surgery, avoiding retransfusion of unwashed cardiotomy suction blood would beneficially alter both urinary and plasma cytokine concentrations and be renoprotective.

METHODS

Thirty-seven OPCAB surgery patients were randomly allocated to control (retransfusion of unwashed shed blood) and treatment (retransfusion of washed shed blood or discarding of unwashed blood) groups. Over 72 hours we measured plasma (tumor necrosis factor-alpha [TNF-alpha], interleukin-8, interleukin-6, interleukin-10, TNF soluble receptor-2, and interleukin-1 receptor antagonist) and urinary TNF soluble receptor-2 and interleukin-1 receptor antagonist and markers of renal injury and dysfunction (N-acetyl beta D glucosaminidase and alpha1-microglobulin).

RESULTS

We demonstrated elevated proinflammatory cytokines in cardiotomy suction blood, which were effectively eliminated by cell salvage. After retransfusion, in comparison with controls, the treatment group had reduced plasma TNF soluble receptor-2. As compared with controls, treatment group patients also demonstrated significantly reduced levels of the urinary anti-inflammatory cytokine TNF soluble receptor-2. There were no between group differences in markers of renal injury or dysfunction.

CONCLUSIONS

We have demonstrated that the management of shed mediastinal blood alters perioperative, systemic, plasma and urinary cytokine homeostasis at OPCAB surgery but does not impact on subclinical renal injury or dysfunction in this low risk group of patients.

Massive blood transfusion and outcome in 1062 polytrauma patients: a prospective study based on the Trauma Registry of the German Trauma Society

BACKGROUND AND OBJECTIVES

About 15% of polytrauma patients receive massive blood transfusion (MBT) defined as > or = 10 units of packed red blood cells (PRBC). In general, the prognosis of trauma patients receiving MBT is considered to be poor. The purpose of this study was to investigate the impact of MBT on the outcome of polytrauma patients.

MATERIALS AND METHODS

Records of 10 997 patients in the Trauma Registry of the German Trauma Society were analysed. Transfusion data were available from 8182 severe trauma patients with a mean injury severity score of 24.5 and, of these 8182 patients, 1062 received > or = 10 units of PRBC. First, a logistic regression model for the predictors of mortality was performed. Second, incidences of organ failure and sepsis as well as survival rates were analysed.

RESULTS

The highest risk for mortality was age over 55 years (odds ratios [OR] 4.7; confidence intervals [CI 95%], 3.5-6.5) followed by Glasgow Coma Scale < or = 8 (OR 4.6; 3.4-6.1), MBT > or = 20 units of PRBC (OR 3.3; 2.1-5.4), thromboplastin time < 50% (OR 3.2; 2.2-4.4) and injury severity score > or = 24 (OR 2.9; 2.1-4.1). Transfusion of 10-19 PRBC was identified as the variable with the lowest risk for mortality (OR 1.5; 1.0-2.3). Risk of organ failure, sepsis and death correlated with increasing transfusion amount. For the MBT patients, the survival rate was 56.9% (CI 95%, 53.9-59.9%) compared to 85.2% (84.4-86.0%) of non-MBT patients (P < 0.001). In the MBT group with > 30 PRBC (mean 40.6 PRBC) 39.6% survived (31.7-47.5%).

CONCLUSION

Massive blood transfusion is one main prognostic factor for mortality in trauma. Although MBT is generally considered to be critical, every second trauma patient with MBT survived. A cut-off value for the number of PRBC could not be determined. Extended transfusion management even with high amounts of PRBC seems to be justified.

Combined use of autologous transfusion techniques to avoid allogeneic transfusion in spinal fusion surgery with instrumentation

This study conducted a retrospective review of the medical records of 321 patients to delineate the efficacy of the combined use of autologous transfusion (AT) techniques. Transfusion profiles between an AT and homologous transfusion (HT) group were compared. A much lower proportion of patients were exposed to allogeneic blood in the AT group (13%) than in the HT group (98%, p<0.001). In the AT group, a significantly smaller proportion of patients were exposed to allogeneic blood in patients transfused with three or four AT techniques (8%) than those with one or two techniques (29%, p<0.05). A febrile reaction (11% of patients) after a reinfusion of post-operatively shed blood was the only side effect associated with an AT. In conclusion, an AT is effective for preventing the exposure of allogeneic blood in spinal fusion surgery. The combined use of multiple AT techniques may further improve its efficacy.

The Impact of Introducing an Autologous Intraoperative Transfusion Device to a Community Hospital

The purpose of this study was to determine the benefits and disadvantages of transfusing autologous blood during abdominal aortic aneurysm (AAA) surgery at a district general hospital with an intraoperative autologous transfusion device (Haemoccel ABT 350). In this retrospective study, 128 patients underwent abdominal aortic aneurysm repair between 1992 and 1999 by a single vascular surgeon. Ninety-three patients (60 autologous and 33 allogeneic) had elective AAA repair (group A) and 25 patients (4 autologous and 21 allogeneic) had emergency AAA repair (group B). Nine group A patients (7.6%) received their own salvaged blood and no other allogeneic blood. Although the mean estimated blood loss was higher in the autologous group of patients (NS), the intraoperative autologous transfusion device did not significantly reduce allogeneic blood usage in patients who had autologous transfusion in both elective and emergency groups. There was no difference in postoperative hemoglobin and hematocrit, ICU stay or hospital stay. In this study, red cell salvage was significantly more expensive than blood bank usage (p < 0.0001), yet it did not significantly reduce the needs of allogeneic blood. We concluded that the intraoperative autologous transfusion device is underused, not cost-effective and requires formulation of local guidelines.

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.

Reinfusion of mediastinal blood after heart surgery

BACKGROUND

Several authors studying autotransfusion of shed mediastinal blood in patients undergoing heart operations have published conflicting results regarding reduction of the need for homologous blood transfusion. The effect on coagulation parameters is also unclear.

METHODS

In a prospective randomized study, 198 patients who underwent coronary artery bypass grafting or a valvular operation were divided into 2 groups: a group with autotransfusion of shed mediastinal blood after an operation and a control group. Continuous reinfusion of mediastinal blood was done until no drainage was present or for a period of 12 hours after the operation. The amount of blood lost and autotransfused, the number of homologous blood products transfused, and the coagulation parameters were monitored.

RESULTS

The number of patients requiring homologous blood transfusion was significantly different between the 2 groups (54/98 [55%] in autotransfused patients vs 73/100 [73%] in the control group, P =.01). The number of re-explorations for excessive bleeding was similar in the 2 groups (7/98 [7.1%] vs 8/100 [8%]), but the amount of blood collected postoperatively was higher in the autotransfused patients compared with control patients (1200 +/- 201 mL vs 758 +/- 152 mL, P =.0007). Coagulation parameters analyzed and complication rates were similar in the 2 groups after the operations.

CONCLUSION

Autotransfusion of shed mediastinal blood reduces the need for homologous blood transfusion in patients undergoing various cardiac operations. The cause of increased shed blood in patients undergoing autotransfusion remains unclear.

Gastro-intestinal complement activation during human liver transplantation: impact on postoperative liver function

BACKGROUND

Liver transplantation elicits a systemic inflammatory response and eventually a multiple organ failure syndrome. Gastro-intestinal inflammatory activation with release of proinflammatory cytokines and complement activation may occur. This study evaluates gastro-intestinal complement activation and the association with postoperative parenchymatous liver cell injury and liver dysfunction.

METHODS

In 17 patients undergoing liver transplantation, blood samples were collected from radial artery and portal vein for analysis of complement SC5b-9 and endotoxin concentration. Portal venous-arterial SC5b-9 plasma concentration gradients at 30 min after reperfusion were calculated. Outcome parameters included postoperative organ failure and serum concentrations of aspartate aminotransferase, alanine aminotransferase, bilirubin and factor II-VII-X.

RESULTS

Patients with gastro-intestinal SC5b-9 release (n=7) had higher postoperative serum aspartate aminotransferase and alanine aminotransferase concentrations [49 (32-80) microkat/l vs 8 (6-14) microkat/l, P<0.01 and 33 (15-54) microkat/l vs 8 (4-23) microkat/l, P<0.04, respectively] and lower factor II-VII-X concentrations [46 (21-48)% vs 60 (47-69)%, P<0.02] compared to patients without gastro-intestinal SC5b-9 release (n=10). The ICU stay was prolonged in patients with gastro-intestinal complement release. There was no difference in number of organ failures and serum bilirubin concentration between the groups. The endotoxin concentration in arterial and portal vein blood was low and the association between endotoxaemia and complement activation was poor.

CONCLUSION

Gastro-intestinal complement activation may contribute to postoperative parenchymatous liver cell injury and liver dysfunction in patients undergoing liver transplantation.