Autologous blood procurement in the surgical setting: lessons learned in the last 10 years

Uterine artery embolization technique for treatment of a huge multi myomatous uterus in a virgin woman

Introduction

Uterine artery embolization is a non-surgical method performed for large and numerous fibroids to preserve the fertility.

Case presentation

The patient is a 36-year-old virgin woman with menometrorrhagia, abdominal pressure, constipation, bilateral abdominal pain, frequent urination and a compressive effect on the intestines was reported to our center. She was diagnosed with uterine fibroids.

Discussion

Because the type of uterine masses and possibility of uncontrollable bleeding during myomectomy and hysterectomy, uterine vascular embolization by supra selective angiography to preserve the uterus was performed. Due to fever, pain and vaginal discharge, she was hospitalized again and hysterotomy was performed without any reported complications.

Conclusion

Uterine artery embolization is a safe method, however reduction and loss in ovarian function can be seen with the treatment. Measurement of follicle stimulating hormone and anti-Müllerian hormone before and after the treatment is important.

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Fibroids are very common, occur individually or in multiple myometrial smooth muscle cells.

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The patient is a 36-year-old virgin woman with menometrorrhagia, abdominal pressure.

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she was hospitalized again and hysterotomy was performed without any reported complications.

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It is also recommended to use egg storage with existing methods if possible, to maintain future fertility.

Prolonged sinus arrest on electrocardiogram recording during apheresis donation in young female donor with convulsive syncope

An 18-year-old young female with a convulsive syncope during apheresis donation demonstrated a prolonged sudden sinus arrest continued for approximately 30-second on monitor ECG. This prolonged sinus arrest may relate accidental serious complications in ordinal apheresis donation. Continuous electrocardiogram monitor and correspondence are indispensable.

Alterations in HbA1c resulting from the donation of autologous blood for elective surgery in patients with diabetes mellitus

BACKGROUND

The aim of this study was to confirm the change in haemoglobin A1c consequent to pre-operative donation of autologous blood for elective surgery in patients with diabetes mellitus.

MATERIAL AND METHODS

For enrolment in this prospective study, patients had to be scheduled for multiple autologous blood donations at different times and have a haemoglobin A1c level more than 5.8% at the first donation. The values of four factors, haemoglobin, haemoglobin A1c, glycated albumin, and glycated albumin/haemoglobin A1c ratio were determined. Changes in the values of these four factors between before and after the blood donations were calculated.

RESULTS

In all 24 patients studied, haemoglobin and haemoglobin A1c decreased as a result of the autologous blood donations. The group with a reduced glycated albumin/haemoglobin A1c ratio had short intervals between blood donations. Correlations were observed between donation interval and change in haemoglobin A1c (r=-0.63, P=0.003), and between donation interval and change in the glycated albumin/haemoglobin A1c ratio (r=0.489, P=0.045).

DISCUSSION

Haemoglobin A1c levels are likely to be underestimated after autologous blood donation by patients with diabetes mellitus, so glycated albumin may be a better indicator of these patients' glycaemic control.

Ten years of preoperative autologous blood donation in accra

SUMMARY BACKGROUND

Preoperative autologous blood donation (PABD) is utilized to circumvent the use of allogenic blood for various reasons.

OBJECTIVE

To describe the distribution in terms of demographic characteristic, trends in participation and result of screening test of the PABD programme of the Accra Area Blood Center from 1993-2003.

DESIGN AND SETTING

Retrospective descriptive study of PABD in patients scheduled for a variety of elective surgical procedures.

SETTING

Different levels of institutional health care in Accra, Ghana.

METHODS

Data from existing records of patients who had participated in PABD were collated and analyzed

RESULTS

Five hundred and forty six (546) females and 89 males participated, with ages ranging between 14-74 years. Majority of the patients (76.7%) underwent gynaecological surgery. A total of 330 (52%) donated one unit only, and 299 (47.1%) donated two units. Majority of the patients (56.4%) had the surgery at the Korle-Bu Teaching Hospital (KBTH). Of the donations, 21 (3.3%), 1 (0.2%), 1 (0.3%) and nil were positive for HBV, HIV I & II, HCV and VDRL respectively. A total of 848 (89.4%) autologous cross-matched units were issued out. There was a steady progressive increase in participation.

CONCLUSION

Mainly adult females scheduled for gynaecological surgeries in KBTH participated, while almost equal proportions donated one or two units of blood which meets the blood needs of most elective surgeries. Therefore healthy patients going for elective surgeries in regions with limited blood supply must be encouraged to enter a PABD Programme. Further studies in this field should evaluate motivational factors for participation.

Autonomic nervous system activity during autologous blood donation for orthognathic surgery

PURPOSE

The aim of this study was to assess by means of power spectral analysis the immediate response of autonomic regulation that occurs with postural change from supine to sitting position (modified head-up tilt test [m-HUT]) during autologous blood donation (ABD) and postphlebotomy infusion.

PATIENTS AND METHODS

We investigated 37 healthy adults who required preoperative ABD before elective orthognathic surgery. Measurements were conducted with m-HUT during ABD and postphlebotomy infusion. The data were analyzed using the maximum entropy method and the difference between supine and tilt was determined by analysis of variance.

RESULTS

When m-HUT was conducted at the resting state, cardiac parasympathetic nervous activity was significantly decreased, whereas cardiac and vascular sympathetic nervous activities were significantly increased. When m-HUT was conducted following blood collection, cardiac parasympathetic nervous activity showed a tendency to increase, whereas vascular sympathetic nervous activity was significantly increased. These changes were not observed during postphlebotomy infusion.

CONCLUSIONS

The m-HUT, which involves postural change from supine to sitting position, may be useful for observing autonomic nervous activity in the clinical setting. ABD carries the risk of imbalance of autonomic regulation. However, postphlebotomy infusion may reduce this imbalance.

A blood-conservation algorithm to reduce blood transfusions after total hip and knee arthroplasty

BACKGROUND

Donation of autologous blood before total joint arthroplasty is inconvenient and costly, causes a phlebotomy-induced anemia, and may be wasteful and unnecessary for the nonanemic patient. We developed a blood-conservation algorithm that does not require predonation of autologous blood, employs selective use of epoetin alfa, and uses evidence-based transfusion criteria. Our hypothesis was that use of this algorithm would reduce the rate of transfusion after unilateral total hip and knee arthroplasty as compared with the rates described in previous reports.

METHODS

We retrospectively reviewed the records of 500 consecutive patients in whom unilateral primary total hip or knee arthroplasty had been performed by a single surgeon. The same blood-conservation algorithm was recommended to all patients. Two groups of patients were identified: the first group consisted of 433 patients in whom the algorithm was followed, and the second group consisted of sixty-seven patients in whom the algorithm was not followed.

RESULTS

In the group in which the algorithm was followed, the rates of allogeneic transfusion after total knee and total hip arthroplasty were 1.4% (three of 220) and 2.8% (six of 213), respectively. The overall rate of transfusion in this group was only 2.1% (nine of 433). The prevalence of transfusion in the group in which the algorithm was not followed was 16.4% (eleven of sixty-seven). This difference was significant (p = 0.0001).

CONCLUSIONS

The use of this blood-conservation algorithm resulted in a significant reduction in the need for allogeneic blood transfusions after unilateral total hip and knee arthroplasty, and the results compare favorably with the rates of transfusion described in previous reports.

Transfusion in surgery and trauma

The role of transfusion in surgery and trauma continues to evolve with our greater understanding of the true indications for and effects of transfusion. The potential adverse immune consequences and end-organ effects of blood transfusion must be weighed against the need for replacement of blood volume and oxygen-carrying capacity. The techniques to conserve blood and avoid transfusion play an important role in caring for the bleeding surgical patient. The future holds great promise for the possibility of redefining the art of blood transfusion and perhaps one day replacing it entirely.

Identifying patients for blood conservation strategies

BACKGROUND

Generally, only the type of operation is used to estimate the need for perioperative homologous blood transfusion. This study quantified the extent to which the estimation could be improved if, in addition, simple patient characteristics were taken into account.

METHODS

Retrospective data on 24 509 consecutive adult surgical patients were used to derive and validate three models to predict perioperative homologous transfusion. The first model was a univariable model with type of operation as the only predictor. The second and third models were a full and a simplified multivariable logistic regression model. The performance of the multivariable models was tested in two validation sets: in similar patients who had operations in the same general hospital (internal validation) and in patients who had operations in a university hospital (external validation). The areas under the receiver-operator characteristic (ROC) curve were compared with that found in the derivation set.

RESULTS

There were no important differences in characteristics between the derivation and validation sets. The ROC area of the model including surgery only was 0.92 (99 per cent confidence interval (c.i.) 0.91 to 0.94) and that of the full and simplified multivariable models 0.95 (99 per cent c.i. 0.94 to 0.96) and 0.94 (99 per cent c.i. 0.93 to 0.95) respectively. The latter two were significantly different from the first one. In the external validation set the ROC area of the simplified model was 0.84 (95 per cent c.i. 0.83 to 0.86). Patients who had a preoperative haemoglobin level lower than 13 g/dl and underwent major invasive surgery had the highest risk (43 per cent) of transfusion.

CONCLUSION

A simple algorithm using type of operation and haemoglobin concentration was effective in identifying patients likely to need perioperative homologous blood transfusion.

Declining value of preoperative autologous donation

BACKGROUND

Preoperative autologous blood donation (PABD) has been shown to decrease allogeneic blood transfusion requirements in major elective surgery. Changes in transfusion practice motivated an examination of blood use from 1993 to 2000 of patients participating in the Héma-Québec PABD program.

STUDY DESIGN AND METHODS

Blood donation and transfusion, type of surgery, and demographic characteristics were prospectively entered into a computer database for patients participating in the Héma-Québec PABD program.

RESULTS

Autologous donations represented from 0.8 to 2 percent of total blood collections and have declined by 26 percent after peaking in 1995. The mean number of units collected per patient declined, as did the number of units transfused per patient and the utilization rate. For radical prostatectomy, knee replacement surgery, hip replacement surgery, and scoliosis, utilization rates were 72, 60, 83, and 78 percent in 1993 compared with 50, 50, 58, and 58 percent in 2000, respectively. In 2000, 18 percent of patients were receiving a 1-unit autologous transfusion. Depending on the surgical procedure, 85 to 95 percent of patients avoided allogeneic transfusion; this did not change significantly from 1993 to 2000.

CONCLUSION

Patients participating in the PABD program successfully avoided allogeneic transfusion in over 85 percent of cases. However, declining utilization rates and frequent 1-unit transfusions demonstrate the decreasing utility of PABD over time.

Autologous blood donation and transfusion in Europe

BACKGROUND AND OBJECTIVES

The aim of this study was to record practices in autologous blood transfusion in Europe in 1997.

MATERIALS AND METHODS

A questionnaire mainly about predeposit was distributed to the National Representatives of all 41 member states of the Council of Europe's Committee of Experts on Blood Transfusion and Haematology. Replies were received from 29.

RESULTS AND CONCLUSION

Autologous blood units collected in 1997 amounted to 4.2% of the allogeneic units, with wide variations between countries. Predeposit was used most frequently in Italy (8.9%), Germany (7.1%) and France (6.6%). Some countries, notably Scandinavia, do not encourage predeposit, chiefly on the grounds that it is not cost-effective, but others are promoting its use.

Efficacy of preoperative autologous blood donation: analysis of blood loss and transfusion practice in total hip replacement

STUDY OBJECTIVE

To determine the frequency of allogeneic transfusion for total hip replacement (THR) surgery and to examine the efficacy of preoperative autologous blood donation (PABD) under specified, standardized blood transfusion guidelines.

DESIGN

Prospective, nonrandomized study.

SETTING

University medical center.

PATIENTS

All ASA physical status I, II, III, and IV patients undergoing single, primary, THR surgery from April 1998 to March 1999.

INTERVENTIONS

All patients received standardized transfusion and anticoagulation therapy. Demographic, blood loss, and transfusion data were collected and compared between all patients participating in PABD (donors) and patients not participating in PABD (nondonors). Overall allogeneic blood exposure was established. Since most anemic patients could not participate in PABD, allogeneic transfusion frequency was also examined in a subset of nonanemic patients (hemoglobin > or =12 g/dL) who were potentially able to participate in PABD.

MEASUREMENTS AND MAIN RESULTS

n = 231 patients, 142 donors and 89 nondonors. Mean estimated blood volume (EBV) of donors was 4991 +/- 1042 mL versus nondonors 4631 +/- 1108 mL (p < 0. 01). ASA physical status I-II/III-IV among donors was 118/24 versus nondonors 61/28 (p < 0.01). Overall allogeneic blood exposure was 22% (51/231). Allogeneic transfusion frequency for all donors was 15% (22/142) versus nondonors 33% (29/89) (p < 0.05). Among nonanemic patients, donor versus nondonor EBV and ASA physical status I-II/III-IV were 5074 +/- 1019 mL versus 4743 +/- 1172 mL and 107/20 versus 48/15 (p = NS); allogeneic transfusion frequency reduced to 13% (16/127) versus 17% (11/63) (p = NS), respectively.

CONCLUSIONS

Allogeneic blood exposure was >10% despite the use of PABD. The efficacy of PABD has been obscured by the fact that donors of autologous blood tend to be larger and healthier than nondonors. After exclusion of anemic patients, autologous donors and nondonors were clinically comparable and the difference in allogeneic blood exposure was not statistically significant. PABD offers only a modest, if any, benefit for THR surgery.

Soluble HLA class I and Fas ligand molecules in blood components and their role in the immunomodulatory effects of blood transfusions

It has been known for many years that blood transfusions may have immunomodulatory effects, however an ultimate explanation of this phenomenon is lacking. In the present paper we report that the concentrations of soluble HLA class I (sHLA-I) and soluble Fas ligand (sFasL) molecules in supernatants of blood components which contain elevated numbers of residual donor leukocytes, like red blood cells and random-donor platelets, are significantly higher than in other blood components. Elevated amounts of sFasL molecules are also found in some commercial immunoglobulin preparations. sHLA-I and sFasL molecules in blood components and in immunoglobulin preparations are biologically active in vitro as they inhibit mixed lymphocyte responses and cytotoxic T cell activity in allogeneic and autologous combinations and induce apoptosis in Fas-positive cells. If these results are paralleled in vivo the amount of sHLA-I and sFasL molecules should be taken into account in clinical practice in order to select the blood component and the immunoglobulin preparation which could induce the desired immunomodulatory effect in the recipient.

Blood conservation in patients undergoing non-cardiac surgery

Concerns about the safety, inventory, and cost of allogeneic blood have led to a renewed interest in blood conservation. Autologous blood collection techniques, including preoperative autologous donation, acute normovolemic hemodilution, and perioperative blood recovery are routinely used as alternatives to allogeneic transfusion. In the future, these techniques may be combined with pharmacological strategies, such as presurgical erythropoietin therapy or red cell substitutes, to reduce further the need for allogeneic blood.

Possible guidelines for autologous red blood cell donations before total hip arthroplasty based on the surgical blood order equation

OBJECTIVES

To determine, in patients undergoing total hip arthroplasty (THA), clinical predictive criteria for preoperative autologous blood donation and to propose guidelines to increase the efficiency and reduce the cost of preoperative autologous blood donation.

PATIENTS AND METHODS

In this retrospective analysis of 165 adult patients undergoing primary THA, a stepwise regression analysis was used to determine which clinical variables predict erythropoiesis in patients donating autologous blood before THA. The surgical blood order equation (SBOE), which includes values for hemoglobin lost at surgery, preoperative hemoglobin level, and minimal acceptable hemoglobin level, was used to estimate the number of units of red blood cells (RBCs) needed for each patient at surgery and thus identify which patients should have made preoperative autologous blood donations.

RESULTS

The statistically significant indicators for RBC production were predonation hemoglobin concentration (P<.001) and male sex (P=.003). Combining the regression equation for erythropoiesis with the SBOE allowed development of guidelines for the use of preoperative autologous RBC donation and erythropoietic therapy. For primary THA surgery, a patient with a predonation hemoglobin level higher than 14.7 g/dL does not need preoperative autologous donation. Preoperative autologous RBC donation would be effective for men with hemoglobin concentrations of 14.7 g/dL or less and for women with predonation hemoglobin levels of 13.2 to 14.7 g/dL. In women whose hemoglobin level is less than 13.2 g/dL, erythropoietic therapy should accompany autologous donation.

CONCLUSION

Incorporation of patient factors with the SBOE system may result in increased efficiency and decreased cost of autologous blood ordering practices before THA.

[Autologous transfusion: when best should not be the enemy of good enough...]

Autologous blood transfusion has been shown to decrease allogeneic transfusion in patients undergoing elective procedures, in adults as well as in children. However, its indication must be carefully discussed for each patient, since, on the one hand, viral risks associated with allogeneic blood are greatly reduced, while on the other hand, adverse events may occur in some patients with poor physical condition. An assessment of the ratio 'benefit-risk' has to be made for each patient.

Perioperative autologous blood donation in children

Autologous blood donation in children has become a standard of care. Children have to live with the life-time complications associated with allogeneic blood including the transmission of known and unknown pathogens, and the impact of alloimmunization on future blood transfusions, organ transplants and pregnancies. Donor reaction, allogeneic exposure and utilization rates in pediatric preoperative autologous donation (PAD) programs are as good if not better than reported in adult literature. Children are very resilient when undergoing extreme isovolemic hemodilution (IHD). PAD, IHD and intraoperative blood recovery appear to be useful components of a pediatric blood conservation program. Prospective, randomized studies addressing the specific needs of children are required to properly define their perioperative role.

Oral or intravenous iron as an adjuvant to autologous blood donation in elective surgery: a randomized, controlled study

BACKGROUND

This study was performed to evaluate the capacity of oral and intravenous (i.v.) iron administration during autologous blood donation (ABD) to improve the efficacy of ABD and to prevent the need for allogeneic blood transfusion in patients without iron deficiency who are undergoing major elective surgery for which a minimum of 3 autologous units have been ordered.

STUDY DESIGN AND METHODS

One hundred twenty-three patients were enrolled in an open-labeled, randomized, controlled trial and assigned to three treatment groups: patients in Group 1 received 3 x 100 mg of Fe2+ per day given orally for 5 weeks before operation; patients in Group 2 received 200 mg of Fe3+ given intravenously after each donation combined with initial i.v. iron supplementation in patients with hemoglobin under 15 g per dL; and patients in Group 3 were in the control group that received no iron medication. A modest ABD program involving weekly phlebotomy and threshold hemoglobin values for donation of 11.5 g per dL in women and 12.0 g per dL in men was performed.

RESULTS

Ninety patients, 15 women and 15 men in each of the three groups, completed the study. The mean net red cell production during ABD was no higher (p>0.2) in the iron-treated groups (Group 1: 473 +/- 178 mL; Group 2: 436 +/- 170 mL; Group 3 (controls): 397 +/- 174 mL). The mean number of autologous units donated per patient did not differ (p>0.7) among the groups (Group 1: 3.1 +/- 0.6; Group 2: 2.9 +/- 0.7; Group 3: 3.0 +/- 0.7). The proportion of patients who needed allogeneic blood transfusion showed no significant (p>0.4) advantage for iron treatment, (Group 1: 7%; Group 2: 20%; Group 3: 10%).

CONCLUSION

In non-iron-deficient patients undergoing modest ABD without erythropoietin therapy, neither oral nor i.v. application of iron during the preoperative period enhances the success of preoperative ABD.

Perioperative blood transfusions: indications and options

A reevaluation of the indications for and alternatives to transfusion of allogeneic blood was precipitated by transfusion-induced HIV. The transfusion trigger has shifted from an optimal hemoglobin level and hematocrit (10/30) to that level of hemoglobin necessary to meet the patient's tissue oxygen demands. This critical level can best be determined by physiologic measurements. A number of autologous blood options can reduce the patient's allogeneic blood needs. Pharmacologic measures to increase hemoglobin levels (erythropoietin) and to decrease blood loss at surgery are discussed as are the potential contributions of blood substitutes to transfusion support of the surgical patient.

Where does preoperative erythropoietin therapy count? A mathematical perspective

BACKGROUND

The administration of erythropoietin (EPO) can be used to increase a patient's hematocrit (Hct) in the preoperative period and thus possibly preclude the need for allogeneic red cells. However, the exact effect on the postoperative Hct of a given rise in Hct in the preoperative period (and on the avoidance of allogeneic blood) has not been thoroughly evaluated.

STUDY DESIGN AND METHODS

Equations were developed on the basis of previously described relationships that allowed the assessment of the impact of a given preoperative Hct increase on the postoperative Hct under a variety of clinical situations.

RESULTS

Equations were derived that related the change in preoperative Hct after the administration of EPO to the final Hct after a given blood loss. In a typical example (blood volume = 5000 mL, pre-EPO Hct of 40%, post-EPO Hct of 45% after blood losses of 1000, 2000, 3000, 4000, 5000, and 6000 mL), an additional 205, 168, 137, 112, 92, and 75 mL of red cells, respectively, would be present postoperatively over the volume in the same patient who did not receive EPO. For a smaller patient, such as a child (blood volume, 2500 mL), an additional 17 mL (5000-mL blood loss) to 83 mL (1000-mL blood loss) of red cells would be present postoperatively. Hemodilution and EPO act synergistically to yield additional postoperative red cell volume.

CONCLUSION

The use of preoperative EPO with a preoperative increase in Hct results in an increased postoperative Hct after a surgical blood loss. Such a postoperative increase is a function of the volume of blood lost and the patient's blood volume but is independent of the patient's initial Hct. The final postoperative red cell volume increase associated with a preoperative increase in Hct of 1 to 5 percent is limited, however (generally equivalent to a fraction of 1 unit of allogeneic blood). Much of the increase in the patient's Hct vanishes at higher blood losses, and this therapy is most effective with blood loss of <4000 mL. EPO therapy alone may be most effectively used in patients with mild anemia who are undergoing routine surgical procedures that commonly require blood transfusion.

Quality of reinfused drainage blood after total knee arthroplasty

Reinfusion of postoperative wound drainage blood has become an attractive alternative in primary total knee and hip arthroplasty. Quality of the drainage blood was studied with respect to content of extracellular bioactive substances and coagulation split products. Using the HandyVac ATS autotransfusion system, drainage blood was collected and reinfused within 6 hours postoperatively from 10 patients undergoing primary total knee arthroplasty. Blood samples were collected from the patients immediately after and 1 hour after opening of the tourniquet and after reinfusion of drainage blood. Samples were also collected from the drainage blood immediately before and at the end of reinfusion. The leukocyte-derived and platelet-derived bioactive substances histamine, eosinophil cationic protein (ECP), eosinophil protein X (EPX), myeloperoxidase (MPO), plasminogen activator inhibitor type 1 (PAI-1), and activated complement factor C3(C3a) and various coagulation factors and split products were analyzed in patient and drainage blood samples. None of the patients received additional predonated autologous blood or allogeneic blood components during the study period. Within 6 hours postoperatively, 250 to 1,000 mL drainage blood was collected and reinfused. Histamine, ECP, EPX, MPO, PAI-1, and C3a content was significantly increased in drainage blood immediately before and at the end of reinfusion. Reinfusion did not change the concentration of these substances in samples from the patients. Coagulation factors and various split products showed that drainage blood was defibrinated. Reinfusion of drainage blood did not change the coagulative capacity of the patients. Drainage blood appears to be defibrinated and contains various extracellular leukocyte-derived and platelet-derived bioactive substances. Reinfusion does not change the coagulative capacity or the concentration of bioactive substances of patients.

Acute normovolemic hemodilution

Acute normovolemic hemodilution was described to be useful as a blood conservation strategy more than 25 years ago, yet seldom is practiced today. The benefit of acute normovolemic hemodilution is perceived to be modest and the technique is not taught in anesthesia or surgery training programs. Acute normovolemic hemodilution is an autologous blood procurement strategy that is superior to the predeposit of autologous blood for several reasons: Acute normovolemic hemodilution is less costly, with an average cost of $25 per unit compared with $175 per unit predonated; and acute normovolemic hemodilution units are reinfused to patients before the patient leaves the operating room, so that the units need not be tested and there is no possibility of administrative error. Emerging clinical studies now show that acute normovolemic hemodilution is equivalent to predonated autologous blood in reducing allogeneic blood exposure in patients undergoing elective surgery.

Oxygen carriers as blood substitutes. Past, present, and future

Prospects for safe and effective blood substitutes are promising, based on clinical trial results of soluble hemoglobin solutions and emulsion of perfluorocarbins. Advantages of blood substitutes include sterilization of viral and bacterial contaminants, room temperature storage, a long shelf life, and absence of ABO and other red cell antigens. Projected arenas for their use include not only military applications but also trauma medicine and elective surgical settings, coupled with acute normovolemic hemodilution. Applications of perfluorocarbons are limited by the need for 100% FIO2. A significant challenge facing development of hemoglobin solutions is their effect on vascular tone through smooth muscle constriction. Development of second or third generation hemoglobin solutions may be necessary so that hemoglobin solutions more closely mimic cellular hemoglobin's nitric oxide binding properties. Optimizing O2 delivery to ischemic tissues and organs may lead to regulatory approval of these agents in this setting before their approval as blood substitutes.

Erythropoietin therapy in the perioperative setting

Recombinant human erythropoietin has been approved for use in patients undergoing autologous donation in Japan, Europe, and Canada since 1993, 1994, and 1996, respectively, and for perisurgical adjuvant therapy without autologous donation in Canada and the United States since 1996. Early clinical trials of erythropoietin therapy in the setting of autologous donation have provided important information regarding clinical safety, erythropoietin dose, and erythropoietic response. Later trials of perisurgical erythropoietin therapy without autologous donation provided data on efficacy (reduced allogeneic blood exposure) that led to approval of erythropoietin in patients undergoing surgery. However, the erythropoietin doses (300 U/kg subcutaneous x14 days) used in these trials, and their subsequent inclusion in labeling for the use of this product, are costly and tedious to administer. A recent study reported that a weekly regimen of erythropoietin (600 U/kg) for 4 weeks is less costly but just as effective at reducing allogeneic blood exposure in elective orthopaedic surgery. The most cost effective regimen that has been shown to minimize allogeneic exposure is preoperative erythropoietin therapy (600 U/kg subcutaneous weekly x2 and 300 U/kg subcutaneous on day of surgery) coupled with acute normovolemic hemodilution in patients undergoing radical retropubic prostatectomy. A similar regimen of erythropoietin therapy in patients undergoing coronary artery bypass grafting (2500 U/kg subcutaneous in divided doses for 2 weeks preoperatively) coupled with hemodilution also was effective. Low dose erythropoietin therapy coupled with acute normovolemic hemodilution ultimately may be shown to be cost equivalent to the predonation of three autologous blood units before elective surgery.

[Benefits and risks of scheduled autologous transfusion]

Blood transfusion, like any other medical activity, requires an analysis of the risk/benefit ratio for each patient. Autologous blood transfusion does not escape this golden rule. The benefits expected of scheduled autologous transfusion consist of the reduction of the risks inherent in homologous transfusion. Those benefits are indisputable in erythrocyte alloimmunisation and viral or parasitic disease transmission. But the risks attached to such protocols have often been underestimated. The risks for the patient are still linked to the transfusion of autologous labile blood products (haemolysis, bacterial infections) or to consequences of whole blood donations (cardiovascular intolerance, increased use of transfusion, increased operative bleeding). There are also risks for the patient community insofar as autologous blood products which do not all meet the same criteria of clinical and biological validation as homologous blood products are circulated in care institutions.

Perioperative myocardial ischemic episodes are related to hematocrit level in patients undergoing radical prostatectomy

BACKGROUND

The anemia associated with perioperative blood conservation has raised concerns regarding the safety of these strategies in patients with ischemic cardiovascular disease. Therefore the relationship between hematocrit level and myocardial ischemic episodes in a group of elderly patients undergoing elective noncardiac surgery was studied.

STUDY DESIGN AND METHODS

One hundred ninety patients undergoing radical prostatectomy were randomly assigned to one of three blood conservation groups: preoperative autologous blood donation, acute normovolemic hemodilution, and preoperative erythropoietin therapy with acute normovolemic hemodilution. Patients underwent ambulatory electrocardiography monitoring to evaluate for myocardial ischemia at randomization (baseline), 7 days preoperatively, throughout surgery, and for 24 hours after surgery.

RESULTS

Myocardial ischemic episodes occurred in 61 (34%) of 181 evaluable patients. Patients with hematocrit levels < 28 percent immediately after surgery were significantly (p = 0.05) more likely to have intraoperative and postoperative ECG ischemic episodes. Intraoperative ischemia and tachycardia correlated (r = 0.21, p = 0.008) with hematocrit levels. Hematocrit levels after surgery were associated with postoperative ischemia (r = 0.14, p = 0.03) and duration of myocardial ischemic episodes (r = 0.14, p = 0.04). After adjusting for other risk factors, intraoperative tachycardia episodes, hematocrit level < 28 percent immediately after surgery, and risk factors for coronary artery disease were independently associated with the likelihood of intraoperative ischemia (r = 0.36, p = 0.002, area under receiver operating characteristic curve = 0.73). Similarly, tachycardia episodes and hematocrit levels < 28 percent immediately after surgery were independently associated with ischemic episodes during the first postoperative day (r = 0.30, p = 0.004, area under receiver operating characteristic curve = 0.71).

CONCLUSION

A hematocrit level < 28 percent is independently associated with risk for myocardial ischemia during and after noncardiac surgery. Avoidance of cardiac complications may require higher transfusion thresholds, closer attention to tachycardia, or better monitoring for ischemia.

The erythropoietic response to erythropoietin in patients with rheumatoid arthritis

We studied whether orthopedic surgical patients with rheumatoid arthritis (RA) can generate an erythropoietic response to either endogenous erythropoietin or to recombinant human erythropoietin (EPO) therapy to the same extent as patients without rheumatoid arthritis (non-RA). Seventy patients (10 RA, 60 non-RA) were entered into clinical trials of aggressive autologous blood donation before elective orthopedic surgery at one institution, randomized to receive EPO (600 U/kg, iv, 6 times over 3 weeks) or placebo. RA patients given EPO had red blood cell (RBC) production that was enhanced by 624 +/- 137 ml (mean +/- SD) as compared with 271 +/- 174 ml (p = 0.02) for RA patients given placebo treatment. Preoperative RBC volume expansion in 10 RA patients was 5.9 +/- 3.7 ml/kg as compared with 7.4 +/- 3.9 ml/kg for 60 non-RA patients (p = 0.13). RA patients can benefit to the same extent as non-RA patients from aggressive blood conservation programs that incorporate erythropoietin-modulated erythropoiesis.