Combined Platelet and Erythrocyte Salvage: Evaluation of a New Filtration-based Autotransfusion Device

BACKGROUND

The SAME device (i-SEP, France) is an innovative filtration-based autotransfusion device able to salvage and wash both red blood cells and platelets. This study evaluated the device performances using human whole blood with the hypothesis that the device will be able to salvage platelets while achieving a erythrocyte yield of 80% and removal ratios of 90% for heparin and 80% for major plasma proteins without inducing signification activation of salvaged cells.

METHODS

Thirty healthy human whole blood units (median volume, 478 ml) were diluted, heparinized, and processed by the device in two consecutive treatment cycles. Samples from the collection reservoir and the concentrated blood were analyzed. Complete blood count was performed to measure blood cell recovery rates. Flow cytometry evaluated the activation state and function of platelets and leukocytes. Heparin and plasma proteins were measured to assess washing performance.

RESULTS

The global erythrocyte yield was 88.1% (84.1 to 91.1%; median [25th to 75th]) with posttreatment hematocrits of 48.9% (44.8 to 51.4%) and 51.4% (48.4 to 53.2%) for the first and second cycles, respectively. Ektacytometry did not show evidence of erythrocyte alteration. Platelet recovery was 36.8% (26.3 to 43.4%), with posttreatment counts of 88 × 109/l (73 to 101 × 109/l) and 115 × 109/l (95 to 135 × 109/l) for the first and second cycles, respectively. Recovered platelets showed a low basal P-selectin expression at 10.8% (8.1 to 15.2%) and a strong response to thrombin-activating peptide. Leukocyte yield was 93.0% (90.1 to 95.7%) with no activation or cell death. Global removal ratios were 98.3% (97.8 to 98.9%), 98.2% (96.9 to 98.8%), and 88.3% (86.6 to 90.7%) for heparin, albumin, and fibrinogen, respectively. The processing times were 4.4 min (4.2 to 4.6 min) and 4.4 min (4.2 to 4.7 min) for the first and second cycles, respectively.

CONCLUSIONS

This study demonstrated the performance of the SAME device. Platelets and red blood cells were salvaged without significant impact on cell integrity and function. In the meantime, leukocytes were not activated, and the washing quality of the device prevented reinfusion of high concentrations of heparin and plasma proteins.

EDITOR’S PERSPECTIVE

Cell salvage using the continuous autotransfusion device CATSmart - an observational bicenter technical evaluation

BACKGROUND

The use of cell salvage and autologous blood transfusion has become an important method of blood conservation. So far, there are no clinical data about the performance of the continuous autotransfusion device CATSmart.

METHODS

In total, 74 patients undergoing either cardiac or orthopedic surgery were included in this prospective, bicenter and observational technical evaluation to validate red cell separation process and washout quality of CATSmart. The target of red cell separation process was defined as a hematocrit value in the packed red cell unit of 55-75% and of washout quality of 80-100% removal ratio.

RESULTS

Hematocrit values measured by CATSmart and laboratory analysis were 78.5% [71.3%; 84.0%] and 73.7% [67.5%; 75.5%], respectively. Removal ratios for platelets 94.7% [88.2%; 96.7%], free hemoglobin 89.3% [85.2%; 94.9%], albumin 97.9% [96.6%; 98.5%], heparin 99.9% [99.9%; 100.0%], and potassium 92.5% [90.8%; 95.0%] were within the target range while removal of white blood cells was slightly worse 72.4% [57.9%; 87.3%].

CONCLUSION

The new autotransfusion device enables sufficient red cell separation and washout quality.

[Effect of autologous blood transfusion device on preventing blood loss in primary total knee arthroplasty using comprehensive hemostatic methods]

OBJECTIVE

To analyze the conventional application of using comprehensive hemostatic methods during the perioperative period, and the effect of autologous blood transfusion (ABT) device compared with non-negative pressure drainage on preventing blood loss and allogenic blood transfusion after primary total knee arthroplasty (TKA).

METHODS

A total of 131 patients (131 knees) with severe knee osteoarthritis who underwent unilateral primary TKA by the same surgeon in Peking University Third Hospital from June 2014 to June 2015 were enrolled in this study. The patients were divided into ABT group (64 patients) and control group (67 patients). ABT devices were used for drainage and blood transfusion in the ABT group while the control group used the non-negative pressure drainage only. The results of the drainage fluid volume, the decrease of hemoglobin, the total blood loss, the hidden blood loss and blood transfusion after TKA were compared between the two groups.

RESULTS

The drainage fluid volume in ABT group was significantly higher than that in control group [515 mL (80-1 610 mL) vs. 260 mL (40-670 mL), P<0.001]. The autologous blood transfusion in ABT group was 245 mL (60-1 070 mL). There were no significant differences between the two groups in the value of hemoglobin decrease 1 day after surgery (P=0.340) and 3 days after surgery (P=0.524). There were no significant differences in the total blood loss (P=0.101) and the hidden blood loss (P=0.062) between the two groups either. There were 9 patients in the 131 patients who received allogeneic blood transfusion, of whom 5 in the ABT group (5/64, the blood transfusion rate was 7.8%) and 4 in the control group (4/67, the blood transfusion rate was 6.0%), and no significant differences in the blood transfusion rate between the two groups (P=0.943).

CONCLUSION

With the conventional application of using comprehensive hemostatic methods during perioperative period, the ABT device did not show the effective result of controlling postoperative blood loss and failed to reduce the rate of allogeneic blood transfusion in patients with unilateral primary TKA. However, the ABT device could increase the drainage fluid volume and improve the patient's hospitalization expenses. Therefore, there is no need for routine application of ABT device in unilateral primary TKA.

Early Experience of Intraoperative Autotransfusion

Intraoperative autotransfusion of whole blood was performed using the Solcotrans device in 45 patients undergoing major vascular surgery or other procedures in which there was a clean operative field. Overall, 60% of the blood shed during these operations was reinfused. Approximately 50% of patients avoided the potential complications of homologous transfusion. There were no complications attributable to the use of this device although in a sample of 13 patients, 30% of the erythrocytes were haemolysed and there were other minor haematological abnormalities. In conclusion this device provides a simple method of autotransfusing 2 or 3 litres of blood aspirated from an uncontaminated operative field.

A Novel Centrifugation Method Using a Cell Salvage Device Offers an Alternative to the Use of Leukocyte-Depleting Filters for Autologous Blood Transfusions

Autotransfusion protocols often use the use of costly filters, such as leukocyte-depleting filters (LDFs), to minimize reinfusion of activated leukocytes and inflammatory mediators associated with reperfusion injury (RI). LDFs are used extensively in hospital settings; however, they represent an additional capital expenditure for hospitals, as well as a constraint on the reinfusion rate of blood products for health-care providers. We compared a commonly used LDF to a novel centrifugation method employing a widely used cell salvage device. Complete blood counts and enzyme-linked immunosorbent assays (ELISAs) measuring tumor necrosis factor-α (TNF-α) and interleukin-2 (IL-2) were performed to compare the efficacy of these methodologies. The LDF removed, on average, 94% of all leukocytes, including 96% of neutrophils. The centrifugation method removed, on average, 89% of all leukocytes, including 91% of neutrophils and resulted in a highly concentrated red blood cell product. Our results suggest both methods offer equivalent leukocyte reduction. TNF-α was also comparably reduced following our novel centrifugation method and the LDF method and IL-2 levels were undetectable in all samples. These results indicate our novel centrifugation method may preclude the need for a LDF during select autotransfusion applications.

Leukocyte removal efficiency of cell-washed and unwashed whole blood: an in vitro study

Leukocyte filtration of the cardiopulmonary bypass (CPB) perfusate after cardiac surgery has evolved as an important technique to prevent effector functions mediated by activated leukocytes. However, little is known about the filtration efficiency. Therefore, an in vitro study was conducted to define the leukocyte removal rate of a transfusion leukocyte-depletion filter, using cell-washed and unwashed whole porcine blood. In addition, the influence of different cell-washing protocols on the elimination rate of blood cells (leukocytes and platelets) was investigated.

Fresh, diluted, pooled, heparinized, porcine blood was processed using either a high-flow (HF, n-5) or quality-wash (QW, n-5) protocol on a continuous auto-transfusion system, or was left unprocessed (control n-5). Thereafter, all samples were filtered using a transfusion leukocyte-depletion filter. Blood samples for measurement of hematocrit, white blood cell count, including leukocyte differentiation and platelet count, were taken before and after filtration. To compare the experimental groups, the removal rate was presented as the fraction of leukocytes or platelets removed per plasma volume.

Cell washing significantly altered the fraction of leukocytes removed per plasma volume when compared to unprocessed blood (2.07 and 2.36 in the HF and QW groups, respectively, versus 1.34 in the control group, p-0.008 for both). No statistically significant difference in leukocyte removal rate was observed between the different cell-washing protocols. The leukocyte differential count showed that, during all experiments, the neutrophils were removed most efficiently (99.7%). Overall, significantly more platelets were depleted after cell washing compared to the control group (1.47 and 1.60 in the HF and QW groups, respectively, versus 1.12 in the control group, p-0.008 and 0.032, respectively). Furthermore, the amount of blood that could be filtered using a single pass technique did not significantly differ between the experimental groups. However, a larger variation in the total amount of filtered blood was observed in the unprocessed group (5709/398 mL) compared to the cell-washed groups (3609/42 and 4309/97 mL in the HF and QW groups, respectively).

In conclusion, blood processing with an auto-transfusion system significantly enhances the leukocyte and platelet removal efficiency of the transfusion leukocyte-depletion filter that was studied. In particular, neutrophils were efficiently removed.

A new practical technique to reduce allogeneic blood exposure and hospital costs while preserving clotting factors after cardiopulmonary bypass: the Hemobag®

Recent data independently linking allogeneic blood use to increased morbidity and mortality after cardiopulmonary bypass (CPB) warrants the study of new methods to employ unique and familiar technology to reduce allogeneic blood exposure. The Hemobag® allows the open-heart team to concentrate residual CPB circuit contents and return a high volume of autologous clotting factors and blood cells to the patient.

Fifty patients from all candidates were arbitrarily selected to receive the Hemobag® (HB) therapy. A retrospective control group of 50 non-Hemobag® (NHB) patients were matched to the HB group patient-by-patient for comparison according to surgeon, type of procedure, age, body surface area (BSA), body weight and CPB time. Many efforts to conserve blood (Cell Saver® and ANH) were employed in both groups. Post-CPB cell washing of circuit contents was additionally employed in the control group.

There were no significant differences between the HB and NHB groups in regard to patient morphology, pre-op cell concentrations, distribution of surgeon or procedures (41% valve, 16% valve/coronary artery bypass graft (CABG), balance CABG), pump and ischemic times and Bayes National Risk scores. The average volume returned to the patient from the HB was 8179/198 mL (1 SD). Average processing time was 11 min. The Hemobag®contained an average platelet count of 2309/80 K/mm3, fibrinogen concentration of 4139/171 mg/dl, total protein of 8.09/2.8 gm/dl, albumin of 4.49/1.2 gm/dl and hematocrit of 439/7%. Factor VII, IX and X levels in three HB contents averaged 259% greater than baseline. Substantial reductions were achieved in both allogeneic blood product avoidance and cost to the hospital with use of the HB.

Infusion of the Hemobag® concentrate appears to recover safely substantial proteins, clotting factor and cell concentration for all types of cardiac procedures, maintaining the security of a primed circuit.

Blood salvage with a continuous autotransfusion system compared with a haemofiltration system

Background: Red blood cells may be destroyed by autotransfusion processing during intraoperative salvage. The aim of the present study was to evaluate the blood component recovery rate of techniques built on either continuous centrifugation and washing, or haemofiltration (HF).

Methods: Two different methods used in blood salvage - red cell salvage with continuous processing with centrifugation and saline washing (Continuous Auto Transfusion System, CATS) and whole blood recirculation through a 30000-Da filter, i.e., HF - were compared in a randomized laboratory study using donor whole blood activated by cobra venom factor. The recovery of red blood cells, haemoglobin, free haemoglobin, leucocytes, platelets, albumin, total protein and potassium was measured.

Results: The recovery of red cells was 86% with CATS and 76% with HF. HF had a significantly higher recovery of leucocytes (CATS 20%, HF 63%), platelets (CATS 4%, HF 37%), albumin (CATS 0.2%, HF 70%), total protein (CATS 1.3%, HF 71%) and potassium (CATS 2%, HF 17%). Less than 1% haemolysis was obtained in processed blood from both groups.

Conclusion: Both methods caused little destruction of the red blood cells during processing. There was a larger reinfusion of leucocytes, platelets, albumin, total protein and extracellular potassium when HF was used compared with the ‘CATS’ method.

Electrolyte and acid/base changes in dogs undergoing autologous blood transfusion via a cell salvage device

This study reports electrolyte and acid/base disturbances observed in clinical cases receiving autologous transfusion of blood processed by a cell salvage device. The records of 12 client-owned dogs that received an autologous transfusion via a cell salvage device with pre- and post-autologous transfusion blood work available were reviewed. Blood work from the 12 case dogs was compared to blood work from 12 control dogs with similar diseases. Control dogs received similar surgical treatment and were administered a similar volume per kg of packed red blood cells as case dogs, but did not undergo autologous transfusion. Case dogs that received autologous transfusion via a cell salvage device were significantly more likely to experience a decrease in ionized calcium and magnesium levels post-transfusion than were control dogs. Calcium and magnesium levels should be closely monitored during and after autologous transfusion. Calcium and/or magnesium supplementation may be required.

Acute hypotension associated with intraoperative cell salvage using a leukocyte depletion filter during management of obstetric hemorrhage due to amniotic fluid embolism

Amniotic fluid embolism (AFE) is a rare but catastrophic obstetric complication that can lead to profound coagulopathy and hemorrhage. The role of cell salvage and recombinant human Factor VIIa (rFVIIa) administration in such cases remains unclear. We present a case of AFE and describe our experience with the use of cell salvage and rFVIIa administration during the resuscitation. Cell salvage and transfusion through a leukocyte depletion filter was attempted after the diagnosis of AFE was made, but the attempted transfusion was immediately followed by hypotension and a worsening of hemodynamics. rFVIIa, on the contrary, was used with clinical improvement in coagulopathy and without apparent adverse thrombotic effect.

Effect of autotransfusion system on tumor recurrence and survival in hepatocellular carcinoma patients

AIM: To investigate the therapeutic efficacy and safety of continuous autotransfusion system (CATS) during liver transplantation of hepatocellular carcinoma patients.

METHODS: Eighty-three hepatocellular carcinoma (HCC) patients who underwent liver transplantation with intraoperative CATS (n = 24, CATS group) and without (n = 59, non-CATS group) between April 2006 and November 2011 at the Liver Transplant Institute of Inonu University were analyzed retrospectively. Postoperative HCC recurrence was monitored by measuring alpha-fetoprotein (AFP) levels at 3-mo intervals and performing imaging analysis by thoracoabdominal multidetector computed tomography at 6-month intervals. Inter-group differences in recurrence and correlations between demographic, clinical, and pathological data were assessed by ANOVA and χ² tests. Overall and disease-free survivals were calculated by the univariate Kaplan-Meier method.

RESULTS: Of the 83 liver transplanted HCC patients, 89.2% were male and the overall mean age was 51.3 ± 8.9 years (range: 18-69 years). The CATS and non-CATS groups showed no statistically significant differences in age, sex ratio, body mass index, underlying disease, donor type, graft-to-recipient weight ratio, Child-Pugh and Model for End-Stage Liver Disease scores, number of tumors, tumor size, AFP level, Milan and University of California San Francisco selection criteria, tumor differentiation, macrovascular invasion, median hospital stay, recurrence rate, recurrence site, or mortality rate. The mean follow-up time of the non-CATS group was 17.9 ± 12.8 mo, during which systemic metastasis and/or locoregional recurrence developed in 25.4% of the patients. The mean follow-up time for the CATS group was 25.8 ± 15.1 mo, during which systemic metastasis and/or locoregional recurrence was detected in 29.2% of the patients. There was no significant difference between the CATS and non-CATS groups in recurrence rate or site. Additionally, no significant differences existed between the groups in overall or disease-free survival.

CONCLUSION: CATS is a safe procedure and may decrease the risk of tumor recurrence in HCC patients.

[Cell saver]

The blood retrievers are instruments increasingly used in operating rooms. They are especially useful in operations where there is a high risk of bleeding and transfusion requirements are high. In paediatrics is of great importance in complex interventions in order to avoid allogeneic transfusion (blood collected from donors). The implementation of the recovery of blood in the surgical field is very simple and easy to use. This is a suction tube that collects the blood that is free, transferring it to a centrifuge where it is filtered and washed, stored in a blood collection bag for subsequent infusion. The blood is of high quality and contains a high hematocrit blood from the bank.

Changes in mechanical fragility and free hemoglobin levels after processing salvaged cardiopulmonary bypass circuit blood with a modified ultrafiltration device

Modified ultrafiltration (MUF) is available for the salvage of post-cardiopulmonary bypass circuit blood. This study evaluated the extent of hemolysis, the mechanical fragility index (MFI), and the amount of plasma free hemoglobin (PFHb) created after processing with the MUF device. Several RBC parameters were measured on pre- and post-MUF device processed samples of blood from 12 patients undergoing cardiac surgery. The MFI and total amount of PFHb did not change significantly between the pre- and post-processing samples: MFI, pre: .19 +/- .06 versus post: .19 +/- .06, p = .76; total amount of PFHb, pre: .24 +/- .21 g versus post: .20 +/- .12 g, p = .42. There was significantly more hemolysis in the post-processing samples compared with the pre-processing samples, .33 +/- .24% versus .96 +/- .48%, respectively, p < .001. Although percent hemolysis was increased following processing with the MUF device, the total amount of PFHb and RBC sublethal injury were not increased. The clinical significance of these findings needs to be determined.

[Mechanic reinfusion in emergency surgery]

The article highlights techniques and effects of intraoperative mechanic blood reinfusion in patients with trauma and intraabdominal bleeding in extend, exceeding the self circulating blood volume. The high efficacy of the self blood reinfusion during the emergency operation allowed the 2-fold decrease of the hospital and overall mortality. The mechanic blood reinfusion proved to be a safe and clinically effective method of the globular blood volume deficiency compensation, especially in emergency surgery.

Autologous transfusion of drain contents in elective primary knee arthroplasty: its value and relevance

BACKGROUND

Total knee arthroplasty is associated with significant post-operative blood loss often necessitating blood transfusions. Blood transfusions may be associated with transfusion reactions and may transmit human immunodeficiency virus, hepatitis C virus and hepatitis B virus, with devastating consequences. After total knee arthroplasty, transfusion of the contents of an autologous drain is becoming common practice. The aim of our study was to look at the effectiveness of these drains in elective primary total knee arthroplasty.

MATERIALS AND METHODS

A prospective study was conducted including 70 non-randomised patients. A normal suction drain was used in 35 patients (group A), whereas in the other 35 patients, a CellTrans™ drain was used (group B). All the operations were performed by four surgeons using a tourniquet with a medial parapatellar approach. Pre- and post-operative haemoglobin concentrations were recorded in both groups. A Student's t-test was applied to determine the statistical significance of the data collected.

RESULTS

The average fall in post-operative haemoglobin was 3.66 g/dL (SD 1.46; range, 0.6-7.0) among patients in whom the simple drain was used (group A) and 2.29 g/dL (SD 0.92; range, 0.6-5.9) among those in whom the CellTrans™ drain was used (group B) (p<0.0001). Twenty-five units of allogeneic blood were required in group A compared to four units in group B. The rate of transfusion was 5.7% (2 patients) in the group in which CellTrans™ drain was used and 25.7% (9 patients) in the group in which a simple suction drain was used.

DISCUSSION

Total knee arthroplasty is associated with significant post-operative blood loss despite best operative technique. Autologous reinfusion of the contents of a CellTrans™ drain significantly reduces the rate of post-operative blood transfusion. This study indicates that the use of an autologous drain could be recommended as routine practice in primary total knee arthroplasty.

Is use of a Continuous Autotransfusion System beneficial in emergency abdominal aortic aneursym (AAA) surgery?

BACKGROUND

Allogeneic blood products have become a limited and expensive resource. The Continuous Autotransfusion System (CATS) has been promoted as a method for reducing the need for allogeneic blood transfusion. This study was undertaken to ascertain whether the use of CATS in emergency open AAA surgery has any benefits.

METHODS

This is a retrospective study of all patients undergoing emergency open AAA surgery in our center during a 5-year period (between July 2004 and July 2009). Patients were identified from a prospectively maintained vascular database, and data were obtained from patient records.

RESULTS

CATS was used in 69 emergency open AAA repairs. The median total blood loss was 3,500 mL (range: 751-13,796 mL) but the median volume of packed red blood cells produced by CATS was only 493 mL (~ 2 U). An average of 7 U (range: 0-19 U) of bank blood was still used despite the availability of CATS. The mean hemoglobin 24 hours postoperatively was 10.3 g/dL (6.4-14.1) with a hematocrit of 0.30.

CONCLUSION

The use of CATS in emergency AAA surgery does not seem to reduce the use of allogeneic blood transfusion. This may be because of over transfusion, as reflected by relatively high postoperative hemoglobin levels.

A comparison of post-op haemoglobin levels and allogeneic blood transfusion rates following total knee arthroplasty without drainage or with reinfusion drains

The effects of re-infusion drains on the rate of allogeneic blood transfusion and post-op haemoglobin levels in Total Knee Arthroplasty were examined. A group of 22 patients undergoing primary Total Knee Arthroplasty using a CBCII Constavac Stryker re-infusion drainage system were compared with a group of 30 patients, matched for age, sex and type of prosthesis but without any drain usage. The re-infusion drain.group had a significantly lower day 1 and day 3 post-operative haemoglobin compared to the non-drainage group. The re-infusion drain group had a higher allogenic transfusion rate compared to the non-drainage group. There were no significant differences between the two groups regarding the rate of wound and transfusion related complications and mean length of post-operative stay. We found that reinfusion drains were ineffective in reducing allogeneic transfusion requirements as compared with non-drainage in total knee arthroplasty.

[Post operatory blood recuperators; bibliographical review]

The authors presented this report at the Apheresis Workshop at the Mexican Congress on Transfusions. VI Annual Congress AMMTAC in Monterrey, Nuevo León district. The use of post operatory recuperators, especially in orthopedic surgery is a habitual practice nowadays. Nurses play a special role in their handling and use; therefore, the authors comment on the reasons why these devices should be used. The authors also state different scientific evidence, based on a bibliographical review regarding the effectiveness of these systems, their utility, their product quality, their cost benefit, and the absence of undesirable effects. The authors conclude that there is a determined patient profile for when a patient benefits from the use of these devices. After some years of high use, at present times, there has been a reduction in using these devices due to, firstly the pre-surgical use of hematin agents, and secondly due to the development of certain less invasive surgical techniques. In spite of this, this procedure has proven to be cost effective. Nurses have an important role in the handling and use of these instruments which, combined with other measures such as the use of hemoglobin analysis devices at the head of a patient's bed, can contribute to an improved management of transfusion requirements.

[Handling of a Bellovac ABT drainage recuperation--blood auto transfusion device]

The authors describe the characteristics of the Bellovac ABT drainage recuperation -blood auto transfusion device along with its proper handling and the required nurses' care in order to minimize the risks and to provide optimum safety for patients. The authors also explain the potential complications and they discuss the main advantages and inconveniences this type of drainage has.

[Why a patient may not be transfused with cell saver not-processed wound blood]

The paper gives information on different clinically important aspects associated with reinfusion of wound and drainage bloods to patients. It considers matters, such as the composition of wound and drainage bloods and its comparison with that of donor blood, as well as that of the cell-saver-washed wound blood; clinical and economic efficiency of the reinfusion of wound and drainage bloods; complications due to the reinfusion of unwashed wound and drainage bloods, as well as a number of other important aspects of the problem. Strong evidence is provided that there are presently no clinical, legal, or economic grounds for the reinfiusion of cell-saver-unwashed wound and drainage bloods in clinical practice. Only cell-saver-washed blood must be reinfiused to a patient.

[Analysis of modern blood reinfusion apparatuses]

The paper gives a brief review of the engineering solutions now applied to the clinical use of a blood reinfusion procedure. It considers simple, transient, and sophisticated (automatic) blood reinfusion methods, their advantages and disadvantages, and the areas of their possible clinical application.

[Effect of instrumental blood reinfusion on clinical parameters and morphology of erythrocytes during aortocoronary bypass grafting]

Erythrocytic morphological changes were studied in 48 patients with coronary heart disease (CHD) at the stages of coronary artery bypass grafting, in whom intraoperative continuous apparatus (CATS, Fresenius, Germany) reinfusion of lost autoblood was used. The patients with CHD were found to have a significant erythrocytic morphological transformation with the oxygen status compensated by the preserved nonpathological forms of erythrocytes. Intraoperatively stable tissue oxygen delivery and rapid blood loss compensation during coronary artery bypass grafting could be provided by continuous reinfusion of lost autoblood that contained valuable erythrocytes after apparatus elimination of disrupted and degenerative forms.

Autotransfusion with cell saver for off-pump coronary artery bypass surgery: a randomized trial

OBJECTIVES

Off-pump coronary surgery reduces transfusions, however, many patients still receive blood. This trial aims to clarify the effect of using a cell saver intraoperatively.

DESIGN

In 60 patients shed blood was collected in the cell saver reservoir intraoperatively; randomization and processing or discharge were performed immediately after surgery.

PRIMARY OUTCOME MEASURES

proportion of patients receiving allogeneic blood, and average number of units per patient.

SECONDARY OUTCOME MEASURES

blood loss, hemoglobin levels, complications, and costs.

RESULTS

Cell saver group versus control group; received transfusions: 17/30 vs. 14/29 (p = 0.28), allogeneic units: median 1 (interquartile range 0 - 2) vs. 2 (IQR 0 - 7) (p = 0.06), intraoperative net blood loss: median 300 ml (IQR 193 - 403) vs. 610 ml (IQR 450 - 928) (p < 0.001). Control group patients had more complications leading to transfusion. Hemoglobin levels and costs were comparable between groups.

CONCLUSIONS

Use of cell saver reduced intraoperative net blood loss and seemed to reduce transfusions by 1 unit per patient, however, this was probably attributable to more complications leading to transfusion in the control group. In the future larger trials are necessary.

[Case of caesarean section using Cell Savers5+ in a patient with the placenta accreta associated with massive hemorrhage]

Placenta accreta which occurs as a complication of total placenta previa is comparatively rare. And the diagnosis of placenta accreta before the caesarean section (C-section) is difficult. We experienced an extremely difficult anesthesia management of placenta accrete because of critical hemorrhage during C-section. We used self-blood collection device Cell Saver5+ (Haemonetics Japan Ltd, Tokyo) for the massive bleeding of 25,500 ml. The Cell Saver could be used to treat life threatening bleeding in C-section without any side effects, although it is thought that the use of the self-blood collection device during C-section had the danger of the amniotic fluid embolism and fetal red cell ontamination. It is necessary to consider using the Cell Saver in the obstetrical operation for life-saving medical treatment in response to unexpected massive bleeding.

[Automatic blood reinfusion in intraabdominal bleedings]

147 patients with polytrauma, complicated by acute large-volume intraabdominal bleeding, were included in the study. Anesthetic regimens and blood loss compensation were retrospectively analyzed. Thus, all patints were divided inti 3 groups: 1st group received only intraoperative blood reinfusion, 2nd group - got auto- and donor blood reinfusion, 3rd group had only donor blood transfusions. Intraoperative autoblood reinfusion allowed an adequate blood loss compensation. The method should be considered a method of choice by acute blood loss treatment during emergency operations in patients with polytrauma.

[Use of a blood recuperating device. Total knee arthroplasty]

The authors evaluate the adoption of a protocol to recuperate blood from drainage during surgery for knee prosthesis. They carried out a prospective study on 19 patients diagnosed with knee arthrosis and who underwent surgery for Total Knee Arthroplasty from September 2006 through June 2007. The medical instrument used was Bellovac, produced by Astral Tech. In the Post anesthesia Reanimation Unit, four patients received a homologous transfusion (27.50%). Prior to the adoption of this protocol, the rate of transfusion was 37%. Hemoglobin during preoperative procedures was not a risk factor for a homologous transfusion. This is associated with the volume drained and reinserted. Patients who received a transfusion had drained 450 cc or more. The study did not record any complication due to the use of the recuperating device. The use of this device made it possible to decrease homologous blood transfusions.

The utility of the perioperative autologous transfusion system OrthoPAT in total hip replacement surgery: a prospective study

BACKGROUND

Total hip replacement (THR) is associated with a significant perioperative blood loss, and 30-50% of these patients receive allogeneic blood transfusion (ABT). We evaluated the clinical utility of washed shed blood (WSB) return to reduce ABT in THR patients.

STUDY DESIGN AND METHODS

Data from 108 consecutive THR patients were prospectively collected. WSB salvage and reinfusion (OrthoPAT) was intended for 60 (Reinfusion group), whereas the remaining 48 patients served as control group. Patients received ABT if haemoglobin <8 g/dl or clinical signs and symptoms of acute anemia.

RESULTS

WSB return was possible in 49 patients (205 +/- 151 ml of erythrocyte/patient), without any clinically relevant incident. Return of WSB decreased both the ABT rate (48 vs. 15%, for control and reinfusion groups, respectively; P = 0.001) and the ABT index (371 +/- 154 ml RBC vs. 53 +/- 117 ml RBC, respectively; P = 0.001), without differences between cemented and uncemented THR. In addition, patients from reinfusion group showed a trend to lower postoperative infection rate (10 vs. 2%, respectively; P = 0.086).

CONCLUSIONS

Perioperative salvage and return of WSB in THR seems to effectively reduce the requirements for ABT. However, for patients with preoperative Hb < 13 g/dl, some additional blood saving method should be associated to WSB return.

Filters in autologous blood retransfusion systems affect the amount of blood cells retransfused in total knee arthroplasty: a pilot study

A pilot study was undertaken to evaluate whether filters integrated in postoperative retransfusion systems affect the amount of blood cells retransfused after total knee arthroplasty. Twenty-two consecutive patients received either the Donor retransfusion system (n=12 patients) or the Bellovac ABT retransfusion system (n=10). Both systems differ with respect to the type of filter, a Pall Lipiguard filter and a Sangopur filter, respectively. At the beginning of the retransfusion, blood samples were taken before and after the filter. The filter of the Donor system significantly decreased the amount of leukocytes and erythrocytes, whereas the filter of the Bellovac system did not. As a result the haemoglobin level of retransfused blood with the Donor system was significantly lower than with the Bellovac system. It can be concluded that the type of filter integrated in two postoperative autologous blood retransfusion systems significantly affected the amount of blood cells retransfused in patients undergoing total knee arthroplasty.

On-line autotransfusion waste calculator

Cell concentrating and washing techniques are widely accepted and believed to be beneficial to cardiac surgery patients. During cell processing, platelets, proteins, and clotting factors are wasted as the plasma is washed away by saline. Beneficial and costly plasma constituents are sacrificed for the sake of removing potentially harmful drugs, debris, and naturally activated cells and chemical mediators. An interactive Microsoft Excel spreadsheet was designed to input patient and autotransfusion system (ATS) reservoir blood values, processed centrifugal bowl data, and hospital allogeneic blood product concentration and cost information. The spreadsheet calculates the number of wasted platelets, grams of protein, and milligrams of fibrinogen. The calculator further estimates the number of units and cost of allogeneic blood products needed to replace the wasted blood components. The simulation allows for variable levels of platelet activation and protein removal during centrifugal cell processing. Specific case scenarios may be simulated with the calculator. If a known volume of residual extracorporeal circuit blood with a known hematocrit, platelet count, and protein concentration is diverted to the ATS reservoir to be processed and washed after bypass, the number of units of fresh frozen plasma, platelet packs, and albumin concentrate needed to replace the wasted proteins and platelets may be calculated. When typical end-bypass patient and blood bank product values are input, the cost to replace the wasted blood components in 1550 mL of residual circuit blood with allogeneic blood products is about US $2097. There are risks and costs associated with replacing the platelets, proteins, and clotting factors wasted during cell washing compared with other techniques such as whole blood ultrafiltration.

Efficacy of cell saver in reducing homologous blood transfusions during OPCAB surgery: a prospective randomized trial

Despite the refinements in surgical technique, rates of homologous blood transfusion (HBT) in cardiac surgery remain high. The adverse effects of blood transfusion are well documented. Retransfusion of shed mediastinal blood reduces the requirement for HBTs during conventional coronary artery bypass grafting. However, some studies have found that autotransfusion leads to bleeding diathesis and paradoxical increase in blood transfusions. Through this prospective randomized trial, we have studied the safety and efficacy of this modality in patients undergoing off-pump coronary artery bypass grafting (OPCAB). Fifty patients enrolled in the study and 49 fulfilled the study criteria. They were randomly divided into group C (cell saver) and group N (non-cell saver). Whereas the cell saver group received processed shed autologous blood and homologous blood if necessary, the non-saver group was transfused homologous blood only. The threshold for transfusion was haemoglobin of 9 g dL(-1) in both the groups. The cell saver group required significantly less number of HBTs (1.6 +/- 1.2 vs. 2.4 +/- 1.3 units). The incidence of re-exploration was zero in both the groups. The mean mediastinal drainage in both the groups was not significantly different (355 +/- 196 vs. 316 +/- 119.8 mL). The number of patients requiring any blood transfusion however was very high. All the patients in the non-saver group and 20 (83%) of the patients in the saver group received homologous blood. During OPCAB surgery, the use of cell saver reduced the requirement for HBT. Its use is not associated with any clinically significant bleeding diathesis.

Improved coagulation and blood conservation in the golden hours after cardiopulmonary bypass

The Hemobag (HB) technique allows the open-heart team to safely concentrate the residual cardiopulmonary bypass (CPB) circuit contents and return a high volume of concentrated clotting factors and blood cells back to the patient as autotransfusion. Hematocrit, platelet count, fibrinogen concentration ([Fib]), prothrombin time (PT), partial thromboplastin time (PTT), and international normalized ratio (INR) were compared between two prospective convenience groups of cardiac surgical patients whose residual circuit blood was processed by the HB (n=10) or by the Cell Saver (CS; n=10) at two times after CPB: (a) after acute normovolemic hemodilution (ANH) infusion and protamine administration and (b) after admission to the intensive care unit (ICU), approximately 1 hour after CPB and HB content infusion. Minimal cell processing was also used in the HB patients to conserve blood. "Golden hours" is defined as the first few hours after CPB and protamine sulfate administration and extend into the ICU, when maintaining hemostasis is vital during cardiac surgery and is the most susceptible period for blood product administration and the opportunity to improve patient outcome. Except for PTT, all parameters changed significantly from the ANH infusion and protamine administration to approximately 1 hour after HB blood infusion and arrival in the ICU. Fibrinogen (p = .048) and hematocrit (p = .046) were significantly higher in the HB group compared with the CS group at the end of the golden hour despite infusion of significantly more allogeneic blood products (p = .070) and more washed red blood cells (RBCs; p = .001) in the CS group. All but one of the HB patients did not receive any allogeneic blood products during the golden hours. Use of the HB technique for salvaging blood is associated with significant increases in the patient's protein and cellular concentrations and lowered coagulation times in the important, first few golden hours after CPB, and except for one patient, without the addition of expensive and precarious allogeneic blood products.

Autotransfusion management during and after cardiopulmonary bypass alters fibrin degradation and transfusion requirements

The coagulation-fibrinolytic profile during cardiopulmonary bypass (CPB) has been widely documented. However, less information is available on the possible persistence of these alterations when autotransfusion is used in management of perioperative blood loss. This study was designed to explore the influence of autotransfusion management on intravascular fibrin degradation and postoperative transfusions. Thirty patients, undergoing elective primary isolated coronary bypass grafting, were randomly allocated either to a control group (group A; n=15) or an intervention group (group B; n=15) in which mediastinal and residual CPB blood was collected and processed by a continuous autotransfusion system before re-infusion. Intravascular fibrin degradation as indicated by D-dimer generation was measured at five specific intervals and corrected for hemodilution. In addition, chest tube drainage and need for homologous blood were monitored. D-dimer generation increased significantly during CPB in group A, from 312 to 633 vs. 291 to 356 ng/mL in group B (p = .001). The unprocessed residual blood (group A) revealed an unequivocal D-dimer elevation, 4131 +/- 1063 vs. 279 +/- 103 ng/mL for the processed residual in group B (p < .001). Consequently, in the first post-CPB period, the intravascular fibrin degradation was significantly elevated in group A compared with group B (p = .001). Twenty hours postoperatively, no significant difference in D-dimer levels was detected between both groups. However, a significant intra-group D-dimer elevation pre- vs. postoperative was noticed from 312 to 828 ng/mL in group A and from 291 to 588 ng/mL in group B (p < .01 for both). Postoperative chest tube drainage was higher in the patients from group A, which also had the highest postoperative D-dimer levels. Patients in group A perceived a higher need for transfusions of red cells suspensions postoperatively. These data clearly indicate that autotransfusion management during and after CPB suppresses early postoperative fibrin degradation.

KEYWORDS

cardiopulmonary bypass, cardiotomy suction, coronary surgery, autotransfusion, fibrin degradation.

Processing of stored packed red blood cells using autotransfusion devices decreases potassium and microaggregates: a prospective, randomized, single-blinded in vitro study

The aim of the study was to compare the potential of autotransfusion devices to reduce non-infectious complications related to transfusion of long-stored packed red blood cells (PRBC; n= 57), such as changes in electrolytes, blood cells and the load of free microaggregates. Following a baseline measurement, a blood pool of three PRBC was divided into three equal volumes and washed with either the Haemonetics Cell Saver (HCS) or the continuous autotransfusion system (C.A.T.S), using the quality (CATS(quality)) and emergency (CATS(emergency)) mode. After the washing procedure, measurements for electrolytes, blood cells and free microaggregates were repeated (n= 19 each). Compared with baseline, the investigated autotransfusion devices reduced the median load of potassium (baseline: 52 mEq L(-1); HCS: 4 mEq L(-1); CATS(quality): 4 mEq L(-1); CATS(emergency): 17 mEq L(-1); each P < 0.001), restored a physiologic electrolyte balance and significantly decreased the load of leucocytes, glucose and protein. Whereas the quantity of microaggregates was not reduced by HCS, CATS(emergency) decreased the load of cell fragments below 7.8 microm (P < 0.05 vs. baseline). Using CATS(quality) decreased the load of cell fragments not only to a diameter below 7.8 microm (P < 0.001 vs. baseline) but also of microaggregates between 7.8 and 17.6 microm (P < 0.05 vs. baseline). In situations where long-stored PRBC have to be transfused, the procedure described here may be feasible to reduce clinically relevant side effects, i.e. hyperkalaemia and microvascular obstruction secondary to free cell fragments. This approach could be especially useful in patients undergoing massive transfusion and/or suffering from renal failure.

Washing of stored red blood cells by an autotransfusion device before transfusion

BACKGROUND AND OBJECTIVES

The use of an autotransfusion device to wash blood of the incision site is increasing. After washing, this blood is retransfused without side effects caused by activated plasma factors and cell release products. This procedure could be extended to washing of donor blood, which may be particularly useful for red blood cells (RBCs) stored for more than 4 weeks that contain high concentrations of free haemoglobin, potassium, lactate and other metabolites. It is not known whether stored RBCs can withstand the cell washing procedure with the use of an autotransfusion device, while keeping their primary functions intact. The objective of this study was to determine the quality of RBCs, after cell washing in comparison to untreated RBCs.

MATERIALS AND METHODS

RBCs were studied in terms of integrity (free haemoglobin), stored energy (2,3-diphosphoglycerate, adenosine triphosphate), metabolites (lactate, potassium) and physical characteristics (osmotic resistance, aggregability, deformability).

RESULTS

After washing, free lactate and potassium were significantly reduced as compared to the levels before washing. The osmotic resistance of RBCs slightly improved, whereas aggregation capacity reduced after washing. Fifteen per cent of haemoglobin was lost during washing. The deformability and free haemoglobin levels remained unchanged.

CONCLUSION

Washing stored blood before transfusion may be of benefit, because the waste products are effectively removed from the stored RBC.

Efficacy, safety and user-friendliness of two devices for postoperative autologous shed red blood cell re-infusion in elective orthopaedic surgery patients: A randomized pilot study

To determine the safety, efficacy and user-friendliness of two different postoperative autologous blood re-infusion systems, an open, randomized, controlled study was performed. Eligible consecutive primary and revision total hip and knee replacement patients were randomized for one of the two systems or for a control group in which shed blood was not re-infused. The nursing staff scored user-friendliness. Patients were monitored after re-infusion. In all three patient groups, a restrictive transfusion trigger was used. Sixty-nine of 70 randomized patients were evaluated. Ease of use, efficacy and safety of both re-infusion systems were comparable. There was no difference in allogeneic blood use between the groups. Thirty per cent of the patients re-infused with autologous blood developed a mainly mild, febrile transfusion reaction. No other adverse reactions were seen. Signs of coagulopathy after re-infusion were not found. In multivariate analysis, autologous re-infusion was an independent factor associated with a shorter hospital stay. Both postoperative autologous blood re-infusion systems were of equal efficacy and safety. The contribution of autologous wound blood re-infusion to reduce allogeneic transfusions must be investigated in a larger study.

[Efficacy of intraoperative apparatus autotransfusion of the blood in revisional endoprosthesis of the hip joint]

Significant blood loss and the methods of its compensation constitute one of the main problems of revisional prosthesis of big joints. Application of a patient's blood constitutes the most available and secure way of the problem solution at the modern stage of surgery evolution. The apparatus autotransfusion of the blood owes prominent place in the system of the blood saving, solely as well as in combination with autodonoring and preoperative hemodilution. In the patients, to whom the revisional prosthesis of the hip joint was performed, using intraoperative apparatus autotransfusion of the blood and the donor's erythrocytes, the red blood indexes were investigated on the stages of operative intervention and postoperative period. Application of apparatuses, such as Cell Saver, constitutes optimal and secure method of the blood oxygentransporting function restoration in the revisional prosthesis of big joints operations.

Randomized Controlled Trial of Pericardial Blood Processing With a Cell-Saving Device on Neurologic Markers in Elderly Patients Undergoing Coronary Artery Bypass Graft Surgery

BACKGROUND

Processing of pericardial shed blood with a cell-saving device was claimed to prevent lipid microembolization and to protect from neurocognitive dysfunction after cardiopulmonary bypass. The present study tested the hypothesis that processing of pericardial shed blood with a cell-saving device during cardiopulmonary bypass would significantly decrease serum levels of protein S100B, and improve brain oxygen saturation and neurologic outcome, all markers of brain injury in elderly patients.

METHODS

Forty patients, 65 years of age and older, undergoing coronary artery bypass graft with cardiopulmonary bypass, were prospectively randomly assigned to processing of pericardial shed blood with a cell-saving device or to conventional use of a standard closed venous reservoir where cardiotomy blood was collected and reinfused through the arterial circuit (control group). Serum in S100B was measured 30 minutes, 4 hours, 24 hours, and 48 hours after surgery. Near-infrared spectroscopy monitoring was performed during the procedure and the National Institutes of Health stroke scale was measured before surgery and at the time of discharge of the hospital.

RESULTS

Patients in the cell-saving device group averaged 72 +/- 3 years of age and underwent 3.1 +/- 0.7 coronary artery grafts with a mean of 62 +/- 20 minutes of cardiopulmonary bypass time. Patients in the control group averaged 75 +/- 4 years of age (p = 0.03) and underwent 3.3 +/- 0.6 coronary artery grafts (p = 0.49) with a mean of 75 +/- 25 minutes of cardiopulmonary bypass time (p = 0.12). The quantity of blood administered from the cell-saving device averaged 281 +/- 162 mL per patient. Serum protein S100B levels averaged 0.06 +/- 0.03 before surgery and 0.51 +/- 0.23 microg/L 30 minutes after surgery in the cell-saving device patients compared with 0.076 +/- 0.04 before surgery (p = 0.32) and 1.48 +/- 0.66 (p < 0.0001) in the control patients. The near-infrared spectroscopy baseline mean value of left and right cortical region was 58% +/- 12% and 55% +/- 7% in the cell-saving device group versus 59% +/- 7% and 53% +/- 6% in the control group (p = 0.67 and 0.36), and no difference occurred over time in each group. The National Institutes of Health stroke score before and after surgery was similar in the two groups. There was one cerebrovascular complication in the control group (1 of 20, 5%) after surgery.

CONCLUSIONS

The difference between the two groups occurred 30 minutes after surgery, at which time serum levels of protein S100B were significantly higher in the control group compared with cell-saving device patients. Although use of the cell-saving device was not associated with higher brain oxygen saturation nor changes in the National Institutes of Health stroke score, it is associated with lesser release of nonspecific markers of brain injury in elderly patients.

A prospective comparison of the platelet sequestration ability of three autotransfusion devices

Although current autotransfusion devices have platelet sequestration capabilities, each has a unique technology to achieve the final platelet product. The purpose of this study was to assess the quality and quantity of platelets sequestered by three different autotransfusion devices. The three commercially available autotransfusion devices evaluated were Fresenius C.A.T.S (closed spiral chamber), Cobe BRAT 2 (Baylor bowl), and Haemonetic Cell Saver 5 (Latham bowl). Platelet sequestration was preformed in the automatic mode following the manufacturer's recommended sequestration protocols. The total number of platelets sequestered, percent recovery, and percent platelet function were assessed. Each device behaved similarly. There was a 2- to 3-fold increase in platelet count compared with baseline with only approximately 50-60% recovery, whereas there was approximately a 10% decrease in platelet function after processing compared with baseline. No statistical difference was noted in platelet function between the respective machines. However, there was a significant loss of platelet function observed with the actual process regardless of autotransfusion device used.

Impact of an autotransfusion system during endoluminal repair of abdominal aortic aneurysms: does it decrease the use of allogeneic blood?

Endoluminal repair of abdominal aortic aneurysms (AAA) is associated with decreased blood loss and transfusion requirements when compared to open AAA repair. We evaluated the use of an intraoperative autotransfusion system during endoluminal exclusion of AAAs. Fifty endoluminal AAA procedures selected at random were reviewed retrospectively. Patients were divided into 4 groups according to their estimated blood loss: Group I, 20 patients (0-500 cc); Group II, 18 patients (501-1,000 cc); Group III, 7 patients (1,001-1,500 cc); and Group IV, 5 patients (1,501-3,400 cc). The average blood loss was 327 cc for Group I, 728 cc for Group II, 1,217 for Group III, and 2,125, for Group IV. The overall blood loss was 834 cc, but 75 per cent was recovered. Hematuria was always present when greater than 1,000 cc of blood was retransfused, but renal function was not affected even with the concomitant administration of radiographic contrast. Only one patient required an autologous blood transfusion. The use of an autotransfusion device is safe, efficacious, and appears to further limit the need for homologous blood transfusion in patients undergoing endoluminal AAA repair.

Particle separation using ultrasound can be used with human shed mediastinal blood

BACKGROUND

Shed mediastinal blood collected by cardiotomy suction has been shown to be a large contributor to lipid microemboli ending up in different organs. The aim of this study was to test the separation efficiency on human shed blood of a new separation method developed to meet this demand.

METHODS

Shed mediastinal blood collected from the pericardial cavity of 13 patients undergoing cardiac surgery with cardiopulmonary bypass was collected. The blood was processed in an eight-channel parallel PARSUS separator, and separation efficiency was determined.

RESULTS

Erythrocyte recovery, in terms of a separation ratio, varied between 68% and 91%. Minor electrolyte changes took place, where levels of sodium increased and levels of potassium and calcium decreased.

CONCLUSION

This study demonstrates that PARSUS technology can be used on human shed mediastinal blood with good separation efficiency. The technology is, thereby, suggested to have future clinical relevance.

[Evaluation of the OrthoPAT autologous transfusion system by experimental models simulating intra- and postoperative blood salvage]

OBJECTIVE

To evaluate the efficacy of the OrthoPAT (Haemonetics) system for blood salvage and for removing chemical or cellular debris, by experimental models simulating intra- and postoperative conditions.

MATERIAL AND METHODS

Blood samples (20%-25% packed red cells) were prepared for the intraoperative model (n=8) and the postoperative model (n=22). Surgical compresses were soaked in some samples (n=5). Other samples were supplemented with hemolyzed blood (n=7). From others cytokines were removed and blood activated with bacterial liposaccharides (n=10) was added. The samples were analyzed before and after processing; tests included detection of free plasma hemoglobin (FPH), potassium ions (K+), glutamic oxalic transaminase (GOT), lactate dehydrogenase (LDH), proteins, and cytokines.

RESULTS

In the intraoperative model 2935 (SD 260) mL of blood was processed. The concentration of packed red cells was 63% and 80% of the red cells were recovered. In the postoperative model 652 (35) mL was processed, the packed red cell concentration was 67% and 81% of the red cells were recovered. Reductions were observed in the concentrations of white blood cells (72%), platelets (88%), GOT and LDH (75%), and proteins and K+ (>95%). Fifty percent of the red cells were recovered in the surgical compresses model. In the hemolysis model, the K+ and FPH concentrations were reduced more than 95%. In the cytokine model, up to 90% of the interleukin 1beta, interleukin 6, and tumor necrosis factor content was removed from the activated blood samples.

CONCLUSIONS

These findings suggest that the OrthoPAT system washes blood and salvages content effectively, recovering 80% of red cells. Moreover, its processing capacity (800-1000 mL x h(-1)) seems adequate for blood replacement in orthopedic surgery.

Quality of thrombin produced from the patient's own plasma using the TPD, a new Thrombin-processing Device

Thrombin derived from bovine sources commonly is used to arrest bleeding during surgical procedures. However, complications such as postoperative hemorrhage can occur because of the development of cross-reactive anti-bovine antibodies that inhibit human coagulation factor V. It would thus be advantageous to develop techniques to generate human thrombin. This study evaluated thrombin produced from human plasma using a new Thrombin-Processing Device (TPD). Plasma was introduced into the TPD, mixed with an ethanol/ CaCl2 reagent, incubated for 1 h, and the harvested thrombin was assayed for activity and the ability to activate platelets by in vitro assays. TPD-produced thrombin activity was found to be 51.8 +/- 12.4 IU/mL (n = 145). TPD-produced thrombin also stimulated P-selectin (CD62) expression (83 +/- 13% of the platelet population) and Annexin V binding (10.3 +/- 2% of the platelet population) on platelets in a similar fashion to commercial thrombin (P-selectin expression: 88 +/- 3%; Annexin-V binding: 11.4 +/- 3%). Compared with CaCl2 and batroxobin, TPD-produced thrombin had a significantly greater ability to activate platelets. TPD-produced thrombin from human plasma has consistent activity and significantly activates platelets and, thus, may have attractive applications such as the production of autologous thrombin for surgical patients.

An economic justification for autologous blood re-infusion in primary total knee replacement surgery

INTRODUCTION

To justify economically the use of autologous blood re-infusion after total knee replacement surgery compared with vacuum drains. To determine if the patients using autologous re-infusion units have a reduced allogenic blood transfusion requirement and hospital stay.

PATIENTS AND METHODS

Prospectively, 50 patients undergoing primary unilateral total knee replacements with autologous re-infusion units were studied. They were matched for age, sex, type of prosthesis and the month in which surgery took place to a second group undergoing the same surgery with vacuum drains. The results for the second group were obtained retrospectively from the notes. The outcome measures were the need for allogenic blood transfusion and length of postoperative hospital stay.

RESULTS

The use of re-infusion units reduced the need for postoperative allogenic blood transfusion from 28% to 4% in total knee replacement surgery. The cost of using re-infusion units was the same as vacuum drains. Overall, the autologous re-infusion patients were discharged 2 days earlier (99% confidence interval).

CONCLUSIONS

Re-infusion units are no more expensive than vacuum drains. In addition, autologous blood has many clinical benefits compared to allogenic blood. Re-infusion may shorten the hospital stay for patients undergoing total knee replacement surgery.