Autologous Blood Donation Research Articles

The use of autologous blood to improve exercise capacity after total hip arthroplasty: a preliminary report

Venesection of red blood cells in healthy well-trained subjects decreased the maximum oxygen uptake parallel with the reduction in hemoglobin (Hb) level. Based on the large Hb decrease that is seen after total joint surgery, one could expect a decrease in performance as well. The purpose of this study was to investigate whether autologous blood enhanced performance on a bicycle ergometer in patients after total hip arthroplasty. Nine patients scheduled for elective total hip arthroplasty in an accelerated stay program participated in a preoperative autologous blood donation (PABD) program. Weeks before the scheduled surgery, patients donated 4 units of blood and received standard erythropoietin treatment. Physical fitness was assessed during exercise test on a bicycle ergometer. Each patient was matched with three previously tested patients. Patients in both groups were 69.0 years old (range, 66-74 years vs. 61-77 years). None of the patients had relevant cardiovascular abnormalities. On average patients received 3.3 units of blood because 3 units were not transfused. The PABD group showed a Hb decrease of 0.5 g per dL (4%) on the fourth postoperative day versus 4.4 g per dL (31%) in the control group. The decline in power output on Day 4 was significantly less in the PABD group compared with the control group (t test, p = 0.026). From this pilot study it can be concluded that correction of the postoperative Hb decrease was associated with a lower decrease in maximum power output, compared to the control group. On Days 23 and 39, however, the difference in performance between the PABD group and control group had disappeared.

Current perceptions of Canadian autologous blood donors

We determined the perceptions and motivations of autologous donors to establish their regard for this process and the new blood system established in 1999 in Canada. Patients were surveyed before and after orthopaedic, cardiac, urological or gynecological procedures. Patients (n = 100; 57 men and 43 women) ranged in age from 19 to 83 years. Most had finished high school, and 21 had a university degree. Eighty-four had undergone previous surgery and 27 a previous transfusion. Fifty-one had been blood donors and 17 had been autologous donors. Specialists suggested donation to 78 of the patients. Seventy-two participated because they knew that their blood would be there. Three had a mistrust of the blood provider. Sixty-six believed that there is still a risk of receiving contaminated blood. Sixty-nine thought any risk was > or = 1 in 100,000; however, 16 thought the risk was < 1 in 1000. Postsurgery, 83 were happy to have donated their blood and 77 would do it again. Many felt that it improved their outcome. Most felt an increased sense of safety. Eighty-three patients were confident that the Canadian blood system had improved, but 17 were unsure. Concern about the safety of the allogeneic blood supply still drives the wish to autodonate. The process gives patients a sense of control and security. A large proportion of people felt that the Canadian blood system had improved, as determined by this 2003 study.

Analysis of Transfusion Predictors in Shoulder Arthroplasty

We are not aware of any previous study that has examined predictive factors for blood transfusion after shoulder arthroplasty. We analyzed the association between clinical factors and the need for postoperative blood transfusion and documented the use and waste of predonated blood in a group of patients managed with shoulder arthroplasty. A retrospective study of 119 patients who underwent 124 shoulder arthroplasties (including eighty-seven primary uncomplicated total shoulder arthroplasties, twenty-seven revision or complicated primary total shoulder arthroplasties, and ten hemiarthroplasties) from 2001 to 2004 was performed. Logistic regression analysis was conducted to determine which clinical variables were predictive of transfusion. A postoperative transfusion was received after thirty-one arthroplasties (25%). The strongest predictor of blood transfusion after shoulder arthroplasty was the preoperative hemoglobin level (likelihood ratio test = 37.8, p < 0.0001). Patients with a preoperative hemoglobin level of between 110 and 130 g/L had a five times greater estimated risk of transfusion than those with a level of >130 g/L (p < 0.001). Gender, body mass index, preoperative diagnosis, comorbid conditions, use of anticoagulants or aspirin, autologous predonation status, type of anesthesia, operative time, and decrease in hemoglobin or hematocrit were not predictors of blood transfusion. One hundred and two (78%) of the 131 predonated autologous units were discarded. Patients with a preoperative hemoglobin level of >130 g/L had the highest percentage of wasted units (90%; fifty-five of sixty-one). Preoperative autologous blood donation did not eliminate the risk of allogeneic blood transfusion in autologous donors. The preoperative hemoglobin level is the strongest predictor of blood transfusion after shoulder surgery, and individuals with a preoperative hemoglobin level of <110 g/L have the highest risk of transfusion. On the basis of these findings, we do not recommend autologous predonation for individuals with a preoperative hemoglobin level of >130 g/L, to avoid unnecessary expense and waste.

ANALYSIS OF TRANSFUSION PREDICTORS IN SHOULDER ARTHROPLASTY

Background: We are not aware of any previous study that has examined predictive factors for blood transfusion after shoulder arthroplasty. We analyzed the association between clinical factors and the need for postoperative blood transfusion and documented the use and waste of predonated blood in a group of patients managed with shoulder arthroplasty. Methods: A retrospective study of 119 patients who underwent 124 shoulder arthroplasties (including eighty-seven primary uncomplicated total shoulder arthroplasties, twenty-seven revision or complicated primary total shoulder arthroplasties, and ten hemiarthroplasties) from 2001 to 2004 was performed. Logistic regression analysis was conducted to determine which clinical variables were predictive of transfusion. Results: A postoperative transfusion was received after thirty-one arthroplasties (25%). The strongest predictor of blood transfusion after shoulder arthroplasty was the preoperative hemoglobin level (likelihood ratio test = 37.8, p < 0.0001). Patients with a preoperative hemoglobin level of between 110 and 130 g/L had a five times greater estimated risk of transfusion than those with a level of >130 g/L (p < 0.001). Gender, body mass index, preoperative diagnosis, comorbid conditions, use of anticoagulants or aspirin, autologous predonation status, type of anesthesia, operative time, and decrease in hemoglobin or hematocrit were not predictors of blood transfusion. One hundred and two (78%) of the 131 predonated autologous units were discarded. Patients with a preoperative hemoglobin level of >130 g/L had the highest percentage of wasted units (90%; fifty-five of sixty-one). Preoperative autologous blood donation did not eliminate the risk of allogeneic blood transfusion in autologous donors. Conclusions: The preoperative hemoglobin level is the strongest predictor of blood transfusion after shoulder surgery, and individuals with a preoperative hemoglobin level of <110 g/L have the highest risk of transfusion. On the basis of these findings, we do not recommend autologous predonation for individuals with a preoperative hemoglobin level of >130 g/L, to avoid unnecessary expense and waste. Level of Evidence: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.

A pilot study of continuous ambulatory monitoring of blood pressure in repeated preoperative autologous blood donation

The aim of this study was to investigate the occurrence of hypotension in the 24-hour period after preoperative autologous blood donation (PABD) in patients with and without hypertension. In 20 patients, 24-hour ambulatory blood pressure monitoring (ABPM) was performed before PABD was started and on every donation day in two repeated phlebotomies. Seven patients had no hypertension and 11 patients had hypertension. In 2 additional patients, hypertension was diagnosed during the study. Overall, the mean systolic BP (SBP) decreased from 131+/-15 mmHg before donation to 128+/-13 and 127+/-10 mmHg after Donations 1 and 2; the corresponding values for the diastolic BP (DBP) were 77+/-9, 75+/-9, and 73+/-7 mmHg, both without significant differences between the groups with and without hypertension. In single patients, substantial decreases of BP occurred, especially during the night. Two patients with and 2 without hypertension showed a nightly decrease in SBP and DBP of more than 10 percent (in 1 of these patients, more than 20%). Concerning diurnal BP variability, 1 patient with and 1 without hypertension, the latter showing a nightly decrease of SBP and DBP of more than 10 percent, also changed to the pattern of a nightly "extreme dipper" after PABD. In 25 percent of the patients, changes of BP were observed during the 24-hour period after PABD, especially during the night, which are known to be associated with an increased risk of cerebral or myocardial ischemia. Whether those changes of BP lead to major morbidity or mortality requires further investigation.

Eingeschränkte, Hämoglobin-abhängige Indikation zum Eigenblutverfahren bei Endoprothesenimplantation des Hüft- oder Kniegelenkes

The rejection rate of autologous blood donation before joint replacement is high. The influence of the haemoglobin value and the age of patient before autologous blood donation was examined according to the necessity for blood transfusion. In a retrospective study, the data of 233 patients who had donated autologous blood before hip (THR) or knee arthroplasty (TKR) were analysed. 72 patients (30.9 %) received an autologous blood transfusion during surgery or in the further course until the first day after surgery. A multivariate analysis showed no significant influence of age on the need for transfusions (p = 0.093), but a higher haemoglobin value before blood donation reduced the risk significantly to 0.712 per unit (1 g/dl). Therefore the age of the patient was less predictive compared to the haemoglobin value as to whether or not a blood transfusion had been necessary. The high security of homologous blood reached in the last years and the knowledge that autologous blood donation reduces the haemoglobin value before surgery has led to the procedure in our hospital only to perform autologous blood donation at the explicit request of the patient.

Does the Use of Erythropoietin Reduce the Risk of Exposure to Allogeneic Blood Transfusion in Cardiac Surgery? A Systematic Review and Meta-Analysis

The use of blood conservation techniques is important in cardiac surgery as postoperative bleeding is common and allogeneic blood transfusion carries the risk of transfusion reactions and infection transmission. Erythropoietin with and without preoperative autologous blood donation is one of the modalities to avoid allogeneic blood transfusion. The objective of this review was to assess the effectiveness of erythropoietin in reducing the risk of exposure to allogeneic blood transfusion during or after cardiac surgery. A meta-analysis of 11 identified randomized controlled trials, reporting comparisons between erythropoietin and control, was undertaken. The primary outcome was the number of patients exposed to allogeneic blood transfusion during or after cardiac surgery. Eleven studies, involving 708 patients, met the inclusion criteria for this review. In total, 471 patients were given erythropoietin, and 237 patients formed the control group. The administration of erythropoietin with and without preoperative autologous blood transfusion prior to cardiac surgery is associated with a significant risk reduction: RR = 0.28 (95% CI 0.18-0.44, P < 0.001) and RR = 0.53 (95% CI 0.32-0.88, P < 0.01), respectively. The administration of erythropoietin before cardiac surgery is associated with a significant reduction in the risk of exposure to allogeneic blood transfusion. Further studies are warranted to define the patients' subgroups that may benefit the most from EPO administration.

Safety of RBC apheresis and whole blood donation in allogeneic and autologous blood donors

Automated red cell collection is now a well-established technology. As with any new method, the risks and benefits must be weighed against older approaches, in this case manual collection. Although widely perceived to be safe, manual collection is associated with a number of potential complications, some of which can be serious, even debilitating. The safety record of 2-RBC and other RBC automated procedures is excellent. Physiologic, cardiovascular, and neurocognitive responses are modest and fall within those seen for manual collection. The long term effects related to erythropoietic response and iron loss are manageable and are similar to the effects of repeated whole blood donation. The collection of whole blood by manual means has been performed for nearly a century and as result the safety of this procedure is assumed. Conversely, the safety of automated collection in general and particularly RBC has had to “prove” itself, primarily because it is much more recent and is a different paradigm. Millions of procedures have been performed using both approaches. The blood donor, the “raw material” which makes hemotherapy possible, is the essential enabler in these processes. This article examines the complications of both manual and automated RBC collection.

Venous Thromboembolism Is Rare with a Multimodal Prophylaxis Protocol after Total Hip Arthroplasty

We evaluated the safety and efficacy of a multimodal approach for prophylaxis of thromboembolism after total hip arthroplasty, which includes preoperative discontinuation of procoagulant medication; autologous blood donation; hypotensive epidural anesthesia; intravenous administration of heparin during surgery and before femoral preparation; aspiration of intramedullary contents; pneumatic compression; knee-high elastic stockings; and early mobilization and chemoprophylaxis for 4 to 6 weeks (aspirin 83%; warfarin 17%). One thousand nine hundred forty-seven consecutive, nonselected patients (2032 total hip arthroplasties) who received this multimodal prophylaxis were observed prospectively for 3 months. The incidence of asymptomatic deep vein thrombosis assessed by ultrasound in the first 171 patients was 6.4%. The incidence of clinical deep vein thrombosis in the subsequent 1776 patients was 2.5%. Symptomatic pulmonary embolism occurred in 0.6% (12 of 1947; nine in patients receiving aspirin and three in patients receiving Coumadin), none of them fatal. One patient died of a myocardial infarct. This multimodal approach is safe and efficacious and compares favorably with those reported in the literature and with our historic controls. If these preventive measures are strictly observed during the perioperative period, postoperative chemoprophylaxis does not need to be aggressive in the patient without predisposing factors. Our low rate of deep vein thrombosis and pulmonary embolism do not support routine anticoagulation prophylaxis with drugs that increase risk of bleeding. Therapeutic study, Level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Preoperative autologous blood donation

SUMMARYBlood‐conservation techniques are declining because of the increasingly safe allogeneic blood supply. However, they continue to be used because of the public’s perception of allogeneic blood risks and increasing blood shortage. Preoperative autologous blood donation (PABD) may decrease the risk of postoperative infection, either because immunomodulation is avoided, or because bacterial or viral infections have to be carefully screened before inclusion of a patient in a PABD program. However, the higher risk of mortality from allogeneic blood transfusion is now more likely due to administrative errors and to blood‐transmitted infection, and the risks associated with banked autologous blood units are similar to those associated with banked allogeneic blood units. Therefore, when PABD is performed inducing anemia, there is an increase of the number of transfused units, thus an increase of the risk related to any transfusion. PABD is most beneficial in procedures that cause significant blood loss, in association with recombinant human erythropoietin administration and blood salvage. Identification of surgical candidates who will need transfusion and will therefore truly benefit from blood conservation must be based on factors specific to the patient, such as the baseline hematocrit and the anticipated blood loss during surgery. Professor Francesco Mercuriali promoted and validated this concept. The appropriate use of autologous techniques should be targeted toward the best possible cost‐effectiveness ratio for an individual patient. Despite its reduced role and declining rationale, PABD must be periodically revisited to assess its role in a changing environment.

Red cell salvage in orthopedic surgery

SUMMARYThe increasing number of surgical procedures has raised the demand for allogeneic blood to a level that often exceeds supply. Moreover, 10% of all transfusions are given in the orthopedic surgery setting, requiring the avoidance of liberal transfusion criteria to further reduce the risk of infection and other complications. As a result, a series of blood‐conservation measures have been developed. In this article, we review the use of autologous transfusion in orthopedic surgery, with a special focus on perioperative red cell salvage.From data reviewed, it can be concluded that perioperative salvage of blood, either intraoperative cell salvage or postoperative cell salvage, seems to be an excellent source of functional and viable red cells, without many of the transfusion‐related risks and with few side effects. The effectiveness of perioperative cell salvage to reduce exposure to allogeneic blood is greatly enhanced by the implementation of a restrictive transfusion protocol and the association with other blood‐sparing strategies [preoperative autologous blood donation (PABD), erythropoietin, intravenous iron], especially in anemic patients. Moreover, perioperative cell salvage may reduce the number of required PABD units or render PABD unnecessary. Finally, although formal cost‐effectiveness studies on perioperative cell salvage are lacking, based on current allogeneic blood transfusion costs, it is generally accepted that the equivalent of at least one unit of blood needs to be recovered for these techniques to be cost‐effective. Therefore, these procedures should be used on a case‐by‐case basis.

Preoperative autologous blood donation in primary total knee arthroplasty: a single‐centre experience on 214 consecutive patients

Although preoperative autologous blood donation (PABD) is a widespread practice in elective orthopedic surgery, it is controversial whether this procedure avoids allogeneic blood transfusions in patients undergoing total knee arthroplasty (TKA). We performed a retrospective study on 214 consecutive patients undergoing PABD before elective primary TKA. Thirty-eight patients (17.8%) were transfused with autologous red blood cells (RBC), while four of them (10.5% of those requiring transfusions, 1.9% of all patients) also received allogeneic RBC. The transfused patients were, in most cases, female and had significantly lower basal and preoperative haemoglobin levels. Based on the results of this study, PABD is not necessary in most patients undergoing TKA, although older female patients with low basal haemoglobin levels could benefit from a predeposit programme and/or erythropoietin support in order to reduce the risk of exposure to allogeneic blood.

Blood transfusions in athletes. Old dogmas, new tricks

Blood doping consists of any illicit means used to increase and optimize oxygen delivery to the muscles and includes blood transfusions, administration of erythropoiesis-stimulating substances, blood substitutes, natural or artificial altitude facilities, and innovative gene therapies. The use of blood transfusion, an extremely straightforward, practical and effective means of increasing an athlete's red blood-cell supply in advance of competition, became rather popular in the 1970s, but it has suddenly declined following the widespread use of recombinant human erythropoietin among elite endurance athletes. Most recently, following implementation of reliable tests to screen for erythropoiesis-stimulating substances, blood transfusions have made a strong resurgence, as attested by several positive doping tests. Doping by blood transfusion can be classified as homologous, where the blood is infused into someone other than the donor, and autologous, where the blood donor and transfusion recipient are the same. The former case produces more clinically relevant side effects, but is easily detectable using current antidoping protocols based on erythrocyte phenotyping by flow cytometry and, eventually, erythrocyte genotyping by DNA testing. Since the donor and recipient blood are identical in autologous blood doping, this is less risky, though much more challenging to detect. Indirect strategies, relying on significant deviations from individual hematological profiles following autologous blood donation and reinfusion, are currently being investigated. For the time being, the storage of athletes' blood samples to allow testing and sanctioning of guilty athletes once a definitive test has been introduced may represent a reliable deterrent policy.

Perioperative Autotransfusion in Total Hip and Knee Arthroplasty

We assessed the OrthoPAT Orthopedic Perioperative Autotransfusion System (Zimmer Inc, Warsaw, Ind) in reducing the need for allogeneic blood in hip or knee arthroplasty. Patients (N = 398) were divided into 5 cohorts: unilateral primary hip (n = 131), unilateral revision hip (n = 38), unilateral primary knee (n = 179), unilateral revision knee (n = 26), and bilateral primary knee (n = 24). Primary or revision hip arthroplasties with no preoperative autologous blood donation, knee arthroplasties with no preoperative autologous blood donation, and unilateral primary hip arthroplasties were 2.7, 2.3, and 2 times less likely ( P < .05), respectively, to use allogeneic blood with OrthoPAT. We conclude that OrthoPAT use significantly reduced the risk of receiving allogeneic blood transfusions in defined patient subsets.

Immunomodulatory Effects of Non-Leukocyte-Depleted and Leukocyte-Depleted Autologous Blood

Based on several in vitro experiments, ithas been suggested that autologous blood transfusionmight lead to immunomodulation and that this effectmight be prevented by leukocyte depletion. Clinical studieswith surrogate endpoints showed conflicting results,whereas studies documenting clinically relevant outcomeswere either too small or methodologically suboptimalto answer this question. Patients and Methods:Participants of a randomized multicenter trial were studied.Patients were scheduled for total hip arthroplastyand preoperative autologous blood donation (PABD) of 2or more autologous whole blood units. Immunologicalparameters were investigated prior to first donation,prior to surgery and on days 1, 5, and 10 after surgery.Results: Leukocyte and lymphocyte subsets changedslightly after donation and considerably after surgery.Monocyte function was slightly suppressed following donationand substantially impaired after surgery. Transfusionslightly counteracted this effect. Leukocyte depletiondid not result in any significant changes of the investigatedimmunological parameters. Conclusion: FollowingPABD immunological changes in patients occur thatcan be attributed mainly to the donation process andsurgery. Transfusion has a minor effect. Leukocyte depletiondoes not appear to contribute substantially to thesechanges.

Preoperative autologous blood donation for bone marrow harvests: Are we wasting donors' time and blood?

Predeposit autologous blood donation (PAD) is frequently offered to bone marrow donors, but its cost-effectiveness is dubious. We assessed the impact of PAD and bone marrow donation on transfusion requirements; and the use of donated blood units in a retrospective study of 61 bone marrow donors. The mean haemoglobin (Hb) concentration fell from 12.9 to 11.8 g dL(-1) in women who predonated one unit and from 13.2 to 10.9 g dL(-1) in those who predonated two units. In men who donated two units of blood, the Hb concentration decreased to 12.9 g dL(-1). Bone marrow harvest led to a further decline in Hb concentration by 2.3 g dL(-1) in women and by 2.4 g dL(-1) in men. The postharvest Hb fell to <or=9.0 g dL(-1) in 39% of female and in 6% of the male donors; all but one of them had predonated blood. The utilization rate of autologous units was 45.6%, with 55% of women and 24% of men receiving autologous blood. In females, 59% of transfused autologous units were given with the donor's Hb of >or= 9.0 g dL(-1); overtransfusion was even more apparent in men: 71% units were given with a Hb >or= 10.0 g dL(-1). PAD in bone marrow donors is associated with high wastage and increases the likelihood of requiring a transfusion. We recommend that PAD should not be routinely offered to bone marrow donors.

Preoperative Autologous Blood Donation in Cardiac Surgery

SUMMARYAutologous blood donation is one of the oldest methods to avoid allogeneic blood tran‐fusion. This method has repeatedly shown to be an effective practice to reduce the exposure of patients to allogeneic blood in cardiac surgery. However, during recent years, this method has been criticized increasingly, mostly for economic reasons. The objective of this overview is to assess the role of autologous blood predonation in cardiac surgery. We evaluated our results in 8235 cardiac surgical patients, of which 18% (1512 of 8235) underwent autologous blood donation. To avoid a selection bias, patients were stratified for preoperative risk score. Of all patients undergoing autologous blood donation 16% received allogeneic blood while 57% of the patients without predonation received transfusion (p &lt; 0.05). Patients without predonation received 1.67 ± 2.8 (mean ± SD) allogeneic units, patients in the autologous group 0.39 ± 1.25 (p &lt; 0.05). Patients with predonation received a higher total number of any transfusion (autologous and allogeneic) compared to patients without predonation (2.39 ± 3.4 vs. 1.79 ± 3.7, p &lt; 0.05). Elective cardiac surgery offers ideal conditions for autologous blood donation mainly because of the high probability of transfusion. In our hands, it was a cost‐effective method to reduce allogeneic blood transfusion. Based on our results, we conclude, that autologous predonation still remains a promising and cost‐effective alternative in the attempt to reduce allogeneic blood transfusion in elective cardiac surgery.

Preoperative autologous blood donation: a therapy that needs to be scientifically evaluated

The aim of preoperative autologous blood donation (PABD) is to reduce both the risk of transfusion transmitted disease and the need of blood from donors. One advantage of PABD is to prevent transfusion-transmitted disease namely viral infections such as HIV or hepatitis virus or emerging virus. Actually, the very low residual risk of allogeneic transfusion does not argue for PABD. On the other hand, the risk of bacterial contamination must be taken in account for both autologous and homologous transfusion (HT). A meta-analysis showed that ABD reduces the exposure to HT (OR: O.17). Clinical studies evidenced that patients who predonated autologous blood were more likely to receive any blood transfusions (autologous and/or allogeneic) than those who did not (OR: 3.31). More, the reduction of exposure to allogeneic transfusion may be questioned in view of prescription bias. Additionally, PABD is poorly cost-effective. It leads to significant blood wastage while in most studies about half of the units are discarded. In conclusion PABD is a therapy that has not been sufficiently evaluated. The interest of this therapy remains to be demonstrated.

The development of an optimized autologous blood donation program

Background Autologous blood (ABD) programs have been in place in Canada since the late 1980s. Activity is decreasing in many sites and utilization averages 50%. Methods In an effort to optimize our ABD program we introduced one time single donation red cell collection (Trima) with and without erythropoietin and compared the results to those with standard red cell collections. A pre-pilot study assessed feasibility. Results To date a total of 59 patients have entered the three arm Trima/epo pilot involving prostate surgery patients: their pre-surgical Hg 158 was compared to 108 in normal autologous control patients. By decreasing the standard pre-donation autologous requirement of three units of red cells to a single Trima collection and at $300 per autologous unit, this represents a cost savings of $36,000 in our 59 patients. When applied to the total autologous program at our hospital (450 per year), this extrapolates to a minimum savings of over $250,000 when using combined collection approaches. 32/59 patients in this pilot study have received only autologous blood, again reducing the number of allogeneic units that would have been required. The need for only a single autologous donation cuts nursing time by 2/3 and also saves laboratory money, since only a single unit is tested for infectious diseases. Conclusion When applied to an autologous blood program, the use of the Trima machine combined with erythropoietin in appropriate cases, results in a decrease in the number of units collected and a higher pre-operative hemoglobin. This program should see application in other sites.

Efficacy of Preoperative Autologous Blood Donation in Free TRAM Flap Breast Reconstruction

Efficacy of Preoperative Autologous Blood Donation in Free TRAM Flap Breast Reconstruction