The utility and prediction of allogeneic blood transfusion use in orthopedic surgery

It is possible to predict the likelihood of postoperative blood transfusion using patient variables. The information could be used to target the high-risk group for intervention(s) that would subsequently reduce the risk of exposure to allogeneic blood. The cost of several of the alternatives to allogeneic blood precludes their use on all surgical patients, and hence the need to identify those patients who are most likely to benefit from such therapy. Further research is needed to assess the impact of predictive models on the use of allogeneic blood and costs. Research is also needed to clarify the impact of blood transfusion on perioperative morbidity and mortality, in patients with and without heart disease. If such an association does indeed exist, then an optimal hemoglobin or transfusion threshold is needed to guide clinicians in caring for their patients.     

Immune responsiveness in orthopedic surgery patients after transfusion of autologous or allogeneic blood

BACKGROUND: The proposed immunosuppressive effect of blood transfusion is not yet understood, and the clinical relevance is a controversial topic of discussion. STUDY DESIGN AND METHODS: The effect of blood transfusions on the capacity of the host's immunocompetent cells to react to mitogenic stimulation was evaluated. Patients undergoing hip replacement surgery received either allogeneic (n = 13) or autologous (n = 14) buffy coat-depleted red cells or plasma. Patients' blood samples taken before and on Days 1 and 5 after surgery were stimulated in a whole-blood assay. The release of interleukin 2, soluble interleukin 2 receptor, interleukin 6, tumor necrosis factor alpha, interferon alpha 2, and interferon gamma was assessed by enzyme-linked immunosorbent assay. In addition, the white cell counts and frequencies of the lymphocyte subsets CD4+, CD8+, and natural killer cells were analyzed. RESULTS: For both groups, decreased levels of interleukin 2 and interferon-gamma were detected postoperatively, whereas the values for soluble interleukin 2 receptor and tumor necrosis factor alpha showed no significant change. Interferon alpha 2 was decreased on Day 1, but returned to normal by Day 5. Interleukin 6 increased during the time of observation. There were no significant differences between the two groups in cytokine production and lymphocyte-subset analysis that could be attributed to the transfusion of allogeneic blood. CONCLUSION: The transfusion of buffy coat-depleted red cells showed no immediate suppressive effect on the immune function of the host's peripheral blood cells.     

Cost-effectiveness of epoetin and autologous blood donationin reducing allogeneic blood transfusions incoronary artery bypass graft surgery

BACKGROUND: Coronary artery bypass graft (CABG) surgery accounts for a substantial portion of all allogeneic units of blood transfused. Drugs and autologous blood donation (ABD) are alternative or adjunctive methods for reducing complications and costs induced by allogeneic blood transfusions. Recombinant human erythropoietin (epoetin) has the potential to decrease perioperative need for allogeneic blood during CABG, but its high cost calls for a careful economic evaluation before it can be recommended for widespread use. STUDY DESIGN AND METHODS: A decision tree was used to compare a hypothetical strategy of no epoetin with one in which epoetin was utilized to control blood transfusion needs in CABG; each strategy was tested with and without ABD. The impact of these strategies on both the quality-adjusted life years (QALYs) and costs ($US) was calculated. RESULTS: Using epoetin alone and with ABD, respectively, avoided the transfusion of 0.61 and 1.35 units of allogeneic blood per patient and saved 0.000086 and 0.000146 QALYs per patient. This made cost-effectiveness (CE) higher than $7 million and $5 million for each QALY saved, respectively. ABD alone cost more than $1 million per QALY saved. If the risk of bacterial infections following allogeneic transfusions was included in the model, epoetin alone cost $6288 per QALY saved, while ABD, both alone and with epoetin, saved money. CONCLUSION: On the basis of the existing evidence, neither of the blood-saving strategies modeled was a cost-effective means of avoiding the deleterious health effects of perioperative blood transfusions in CABG. However, if allogeneic blood-related infections were to be considered, both ABD and epoetin would be acceptable interventions.     

Autologous blood pre-deposit and cell salvage in orthopedic surgery

A successful autologous blood program should enrol all appropriate patients, conserve homologous blood and minimize the exposure to the risks of donor blood. A program of autotransfusion and proper use of blood has been implemented since 1980 with the objectives of including all eligible patients and to transfuse autologous blood only. The following strategies were adopted: critical review of transfusion indications; control of over-transfusion; avoidance of waste; systematic and integrated use of all autotransfusion techniques currently available. Results in 1992 in elective surgery: 98% enrolment, 75% blood conservation. Exposure to homologous blood was completely avoided in 53% of the cases.     

A retrospective study evaluating single-unit red blood cell transfusions in reducing allogeneic blood exposure

Although guidelines recommend the use of single-unit red blood cell (RBC) transfusions to minimize allogeneic blood exposure, clinical practice remains dominated by two-unit transfusions. This study assesses the potential impact of a single-unit transfusion policy on reducing RBC utilization. We performed a retrospective analysis of adult patients admitted to a tertiary care hospital who received one or two RBC units. In subjects transfused two units, the effect of one unit was estimated by dividing the change in haemoglobin by 2. The proportion of patients reaching a haemoglobin threshold of 70, 75, 80, 85 and 90 g L(-1) with a single RBC unit was estimated. Of 302 included patients, only 65 received a one-unit transfusion. Based on thresholds of > or = 90, > or = 80 and > or = 70 g L(-1), a single-unit transfusion would be sufficient in 42.0% (RRR = 0.54), 79.6% (RRR = 0.23) and 98.0% (RRR = 0.02) of cases, respectively. This corresponds to 0.21, 0.57 and 0.82 mean RBC units saved per patient. In the orthopaedic subpopulation, the mean RBC units saved are 0.53, 0.88 and 1.00 for the same haemoglobin targets. Adopting a policy of transfusing RBC in single-unit aliquots could significantly improve RBC utilization and decrease patient exposure to allogeneic blood.     

Integrated strategies for allogeneic blood saving in major elective surgery

Background

Large use of allogeneic red blood cell concentrates (RBCc), albeit necessary in major surgery, may influence patients’ outcome.

Design and methods

We introduced an integrated strategy including patients’ evaluation and supplementation associated with autologous blood collection and saving to support major elective surgery at our hospital since 2008. After 2 years of stabilization of this approach, we analyzed the results obtained in 2010 in terms of allogeneic blood usage and reduction of transfusion of stored RBCc.

Results

Analyzing 2010 results we found that usage of total autologous RBCc units was increased by 2.2 folds, of “not stored” autologous RBCc units by 2.4 folds and of allogeneic RBCc unit transfusion reduced by 65%. The significant reduction in the number of transfused allogeneic RBCc units associated with the use of “fresher” blood could prevent patients’ complications due to immunomodulation and biologic/metabolic disregulation.     

Detection and removal of fat particles from postoperative salvaged blood in orthopedic surgery

BACKGROUND: Although transfusion or return of salvaged shed blood has become popular in major orthopedic procedures, this blood-saving method is still controversial because shed blood may be contaminated with chemical and tissular debris, such as fat particles, which may increase the risk of fat embolism after bone surgery. STUDY DESIGN AND METHODS: In an effort to find an easy, reliable method for determination of both fat particle content and removal from shed blood, analyses of perioperative blood samples were performed with a cell counter (Technicon H3 [H3]) in orthopedic patients undergoing spinal fusion in which postoperative shed blood was collected and returned with a blood collection canister. A screen or surface filter was intercalated in the return line to eliminate microaggregates, fat particles, and/or WBCs. RESULTS: Fat particles in shed blood are clearly detected as a condensed, sigmoidal-shaped area at the right-hand side of the PMN zone in the channel in which the H3 measures particles according to their degree of lobularity. This signal can be reproduced by the addition of animal or vegetable fat to venous blood, but not by the addition of activated platelets or RBC membranes. Fat particles, together with WBCs and microaggregates, in shed blood were effectively removed by surface filters, whereas screen filters were not effective. CONCLUSION: The use of the TH3 seems to be an easy, reliable, and low-cost approach for monitoring fat particle content and removal from postoperative salvaged shed blood in orthopedic procedures.     

Ethical challenges in orthopedic surgery

Despite our recent attention to ethical issues in orthopedics, we are still faced with multiple conflicts of interest that continue to pose ethical dilemmas to the practicing physician. Using four case scenarios, we review the potential conflicts of interest and the dilemmas posed by these frequently encountered situations. The ethical conflicts confronted in resident training, the introduction of new technology, physician advertising, and the obligations of the sports team physician are reviewed and discussed. The basic principles of medical ethics, including acting for the good of the patients and doing no harm, are discussed in the context of the four case scenarios.     

Risk for postoperative infection after transfusion of white blood cell-filtered allogeneic or autologous blood components in orthopedic patients undergoing primary arthroplasty

BACKGROUND: This study was designed to obtain data on the incidence of postoperative infection in patients undergoing elective orthopedic surgery and receiving white blood cell (WBC)-filtered blood components prepared according to current standards. STUDY DESIGN AND METHODS: A total of 308 consecutive orthopedic patients who opted for preoperative autologous blood donation (PAD) for primary unilateral hip and knee replacement surgery were enrolled in a prospective observational study of the incidence of postoperative infection. Patients with contraindications for PAD or with any infectious disease were not included in the study. To identify probably confounding factors, differences between patient groups were analyzed first. Identified factors, which differed between groups, and variables describing blood supply were further tested in uni- and multivariate logistic regression analysis for their independent influence on development of postoperative infection. Infection rates were compared on the basis of actual transfusion groups. RESULTS: Of the 308 study patients, 101 were not transfused, 85 received their PAD, 100 received allogeneic WBC-filtered red blood cells (RBCs), and 22 were given autologous RBCs and additionally allogeneic WBC-filtered RBCs. Overall the infection rate was 6.82 percent (21/308). Infection rates varied significantly between transfusion groups (no transfusion, 6.9%; autologous RBCs, 1.2%; allogeneic WBC-filtered RBCs, 12.0%; both transfusion types, 4.6%; p = 0.03). Allogeneic recipients showed significantly more infections compared to autologous recipients (p = 0.0053). Multivariate regression analysis confirmed transfusion of allogeneic WBC-filtered RBCs as an independent variable predicting postoperative infection (odds ratio, 23.65; confidence interval, 1.3-422.1; p = 0.01). CONCLUSION: Differences in postoperative infection rates between allogeneic and autologous recipients are still observable, although universal WBC filtration has been introduced into clinical practice.     

The bipolar sealing device: reducing blood loss in orthopaedic surgery

Perioperative blood management continues to be a challenge in major orthopaedic surgical procedures. Techniques used have varied through the years, and ongoing attempts to minimize patients' exposure to allogeneic blood continue to be explored.To date, the majority of blood management options focus on either blood replacement with safe effective blood products or the preoperative stimulation of red blood cell production in the surgical patient with erythropoietin.This article describes a new device that uses thermal energy to inhibit blood loss from soft tissue and bone during orthopaedic surgery. Early clinical trials indicate that the bipolar device may reduce blood loss and decrease exposure to blood transfusions.     

The value of autotransfusion in the management of intraoperative blood loss during orthopedic surgery

The principal advantage of autologous blood transfusions is the danger of transmitting infectious agents and the adverse immunomodulatory effects of allogenic transfusion can be avoided. The effectiveness of preoperative autologous blood donation in reducing allogenic blood exposure is undisputed. The current discussion focuses on cost effectiveness versus the potential risks of autologous blood donation, and on transfusion criteria for autologous versus allogenic blood. The cost effectiveness of autologous blood donation may indeed be low, mainly due to the high percentage of units discarded. On the basis of current literature, the authors describe various types of autotransfusion, current opinions the regarding benefits and risks of autotransfusion, and some of the economic aspects of autotransfusion.