The safety and efficacy of "bloodless" cardiac surgery

Nearly 20% of blood transfusions in the United States are associated with cardiac surgery. Despite the many blood conservation techniques that are available, safe, and efficacious for patients undergoing cardiac surgery, many of these operations continue to be associated with significant amounts of blood transfusion. Although surgical bleeding after cardiopulmonary bypass is a common problem as reflected by the substantial use of blood products, it is the individual physician and institutional behavior that have been identified as reasons for transfusion and not necessarily patient comorbidity or blood loss. Transfusion rates in cardiac surgery remain high despite major advances in perioperative blood conservation, with large variations among individual centers. The adoption of available blood conservation techniques, either alone or in combination in patients undergoing cardiac surgery, could result in an estimated 75% reduction of unnecessary transfusions. The success of previously reported blood conservations programs in cardiac surgery should call for a reevaluation of allogeneic transfusion practices in patients undergoing cardiac surgery. By applying the numerous reported blood conservation strategies for the management of patients presenting for cardiac surgery, we can preserve our dwindling blood resources and help alleviate some of the direct costs of blood as well as the indirect costs of treating noninfectious and infectious complications of transfusion.     

Bloodless cardiac surgery is associated with decreased morbidity and mortality

BACKGROUND: Blood transfusion with cardiac surgery accounts for 20% of transfusions in the United States. The effect of perioperative transfusion on cardiac surgery outcomes is unknown. We hypothesized that cardiac surgery with perioperative blood transfusion was associated with worse outcomes. METHODS: A prospectively maintained (Society of Thoracic Surgeons) institutional database was analyzed from 2000 to 2005. All patients undergoing coronary artery bypass and/or valve operations were evaluated for the association of preoperative and intraoperative risk factors with blood transfusion. The association of transfusion with postoperative complications and mortality was evaluated. RESULTS: During the study period, 2691 patients met inclusion criteria. Sixty-four percent received transfusions. Preoperative risk factors associated with transfusion (p < 0.05) were lung disease, elevated creatinine, peripheral vascular disease, and previous cardiac interventions. Patients requiring transfusion were older (mean 65.2 vs. 61.2 years, p < 0.001). Transfusion was associated with longer cross-clamp (median 78 vs. 88 minutes, p < 0.001) and perfusion times (median 114 vs. 128 minutes, p < 0.001). Perioperative blood transfusion was associated with increased postoperative complications (53.5% vs. 30.5%, p < 0.001). Significant transfusion-associated complications were renal failure, prolonged ventilation time, pneumonia, cardiac arrest, gastrointestinal complications, atrial fibrillation, stroke, myocardial infarction, and bleeding requiring reoperation. Blood transfusion was associated with an increased operative mortality (3.4% vs. 1.7%, p = 0.005) and length of stay after surgery (median 6 vs. 5 days p < 0.001). CONCLUSION: Identification and management of risk factors associated with transfusion may reduce the transfusion requirement, minimize perioperative complications and improve outcomes. Bloodless cardiac surgery is associated with a decreased morbidity and mortality.     

Transfusions in patients undergoing cardiac surgery with autologous blood

PURPOSE: Determinants of allogeneic blood use in cardiac surgery include preoperative factors such as female sex, age, body weight, hematocrit and red cell volume. We verified if these variables also predicted the need for allogeneic transfusions when autologous blood is predonated. METHODS: Demographic and intraoperative variables, hemoglobin concentrations and transfusion requirements in patients undergoing cardiopulmonary bypass with autologous blood predonation were reviewed. Multivariate logistic regression and RECPAM tree-growing analyses were applied to identify the preoperative predictors of allogeneic transfusion in these patients. RESULTS: Data from 230 patients included in our autologous blood program between 1995 and 1998 were analysed. Patients undergoing complex/reoperative surgical procedures and patients over age 64yr with a low red cell volume (<2070ml) undergoing simple procedures were more likely to require allogeneic red cells. Younger patients with a low red cell volume undergoing simple procedures carried an intermediate risk. Allogeneic transfusion was avoided in 95% of patients undergoing simple procedures when red cell volume > or = 2070ml. CONCLUSIONS: In our institution, complex/reoperative surgery, low red cell volume and increased age are the main factors associated with the need for allogeneic red cell transfusion despite autologous blood predonation. Knowledge of the factors that limit the effectiveness of predonation with respect to allogeneic blood exposure should help clinicians decide which cardiac surgical patients should be included in autologous blood programs.     

Preoperative anemia in orthopedic surgery: clinical impact, diagnostics and treatment

In a national audit of elective orthopedic surgery conducted in the US, 30% of patients were found to have hemoglobin (Hgb) levels ?10%. However, one of these measures, the autologous blood donation, can exaggerate anemia and can increase the overall transfusion rates (allogeneic and autologous). As autologous procedures (autologous blood donation and cell salvage) are not always appropriate for anemic patients together with an expected shortage of blood and because preoperative anemia is associated with perioperative risks of blood transfusion, a standardized approach for the detection, evaluation and management of anemia in this setting was identified as an unmet medical need. A panel of multidisciplinary physicians was convened by the Society for Blood Management to develop a clinical care pathway for anemia management in elective surgery patients for whom blood transfusion is an option. In these guidelines elective surgery patients should have Hgb level determination at the latest 28?days before the scheduled surgical procedure. The patient target Hgb before elective surgery should be within the normal range (normal female ≥?120?g/l, normal male?≥?130?g/l). Laboratory testing should take place to further determine nutritional deficiencies, chronic renal insufficiency and/or chronic inflammatory diseases. Nutritional deficiencies should be treated and erythropoiesis-stimulating agent (ESA) therapy should be used for anemic patients in whom nutritional deficiencies have been ruled out and/or corrected.     

Blood transfusion and surgery: the effect on growth of a syngeneic sarcoma.

The effects of blood transfusion, blood components, and surgical trauma on the growth of an experimental sarcoma have been examined. Recipient animals were inbred adult female WAB rats, which received allogeneic transfusions from inbred adult female PVG rats, syngeneic blood from inbred colony-mates, or saline infusions. Small volume transfusions (1-4 ml) of whole blood had no effect on tumour growth, but growth of the MC7 sarcoma was significantly enhanced following allogeneic transfusions of 5 ml whole blood, or when 4 ml was combined with sham laparotomy. Maximal enhancement of tumour growth occurred when 4 ml transfusions of allogeneic washed cells were given, but allogeneic plasma was also able, to a lesser degree, to enhance tumour growth. These data confirm that blood transfusion may enhance growth of the MC7 sarcoma, that the effect may be dose dependent, and synergistic with the immunosuppression of surgery. Many components of an allogeneic transfusion may be responsible for this effect.     

Perioperative blood transfusions and delayed wound healing after hip replacement surgery: effects on duration of hospitalization

Patients who receive allogeneic blood transfusions after orthopedic surgery have a longer duration of hospitalization, and this cannot be explained by a more frequent incidence of infections in transfused patients. To determine whether transfusion of allogeneic blood interferes with wound healing and therefore increases the duration of hospitalization, we performed an observational study in 444 consecutive patients scheduled for elective primary hip surgery. Transfusion, wound, and infection variables were collected at five time points during treatment. Of the 444 consecutive patients studied, 92 received blood transfusions during their perioperative course. Thirty-one percent of transfused patients developed wound-healing disturbances versus 18% of the nontransfused group (P < 0.05); allogeneic blood transfusion was the only significant predictor for development of minor wound-healing disturbances. Duration of hospitalization was prolonged in transfused patients (12.3 versus 9.8 days) and could be predicted by 4 significant variables: requirement for blood transfusion (adds 2.7 +/- 0.5 days), presence of wound-healing disturbances (adds 1.3 +/- 0.5 days), duration of surgery (adds 0.2 +/- 0.1 days/10 min), and patient's age (adds 0.9 +/- 0.2 days/10 yr). These data suggest that allogeneic blood transfusion is associated with an increased incidence of wound-healing disturbances and that prevention of allogeneic blood transfusion may be relevant in limiting the duration of admission after elective orthopedic surgery.     

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.     

Präoperative Eigenblutspende in der Herzchirurgie

BACKGROUND: Preoperative autologous blood donation is an effective method to reduce allogeneic transfusion requirement. However, this method is only rarely utilized in cardiac surgery. Besides economic concerns one essential argument against predonation is the lack of sufficient time due to the short waiting lists. The aim of the present study was to investigate the efficacy of autologous predonation to reduce allogeneic blood transfusion in routine cardiac surgery on a center without longer preoperative waiting lists. PATIENTS AND METHODS: A total of 2,626 cardiac surgery patients were included. Primary endpoint of the study was the perioperative incidence of allogeneic packed cell transfusion. If time between diagnosis and admission to the hospital was >10 days, predonation was offered to the patients. Data were stratified for preoperative risk score. Logistic and linear regression analysis tested the influence of different variables on the incidence of allogeneic blood transfusion and the total amount of allogeneic blood. RESULTS: Of all patients 267 (11.2%) underwent predonation. The incidence of allogeneic packed cell transfusion was reduced from 53% to 19% by autologous predonation (p<0.001). The total amount of allogeneic blood transfused was significantly different between the groups (2.2+/-4.2 vs. 0.84+/-6.3 units; p<0.001). DISCUSSION: Autologous predonation in cardiac surgery was effective in reducing blood transfusions even in the absence of longer preoperative waiting times. It is a safe and effective method to minimize blood transfusion in cardiac surgery.     

Variability in Transfusion Practice for Coronary Artery Bypass Surgery Persists Despite National Consensus Guidelines: A 24-Institution Study

Background: An estimated 20% of allogeneic blood transfusions in the United States are associated with cardiac surgery. National consensus guidelines for allogeneic transfusion associated with coronary artery bypass graft (CABG) surgery have existed since the mid- to late 1980s. The appropriateness and uniformity of institutional transfusion practice was questioned in 1991. An assessment of current transfusion practice patterns was warranted.

Methods: The Multicenter Study of Perioperative Ischemia database consists of comprehensive information on the course of surgery in 2,417 randomly selected patients undergoing CABG surgery at 24 institutions. A subset of 713 patients expected to be at low risk for transfusion was examined. Allogeneic transfusion was evaluated across institutions. Institution as an independent risk factor for allogeneic transfusion was determined in a multivariable model.

Results: Significant variability in institutional transfusion practice was observed for allogeneic packed red blood cells (PRBCs) (27-92% of patients transfused) and hemostatic blood components (platelets, 0-36%; fresh frozen plasma, 0-36%; cryoprecipitate, 0-17% of patients transfused). For patients at institutions with liberal rather than conservative transfusion practice, the odds ratio for transfusion of PRBCs was 6.5 (95% confidence interval [CI], 3.8-10.8) and for hemostatic blood components it was 2 (95% CI, 1.2-3.4). Institution was an independent determinant of transfusion risk associated with CABG surgery.     

Perioperative management of four anaemic female Jehovah's Witnesses undergoing urgent complex cardiac surgery

Previous studies have demonstrated that preoperative haemoglobinconcentration and female gender are related to an increasedneed for perioperative allogeneic transfusions in cardiac surgery.Hence, urgent cardiac surgery presents a dilemma for femalepatients who are Jehovah’s Witnesses, because of theirrefusal of allogeneic transfusion. This report describes themanagement of four high-risk anaemic female patients undergoingurgent complex cardiac surgery. In these Jehovah’s Witnesspatients, strict application of a comprehensive blood-sparingprotocol permitted safe avoidance of allogeneic transfusions.The protocol involved intraoperative acute normovolaemic haemodilution,intraoperative administration of tranexamic acid, intra- andpostoperative use of a cell-saver system, postoperative administrationof erythropoietin, iron and folic acid, and a careful surgicaltechnique to avoid perioperative bleeding.     

Survival advantage of using autologous blood transfusion during surgery for esophageal cancer

Purpose: There is evidence that blood transfusion is associated with an increased rate of tumor recurrence. This study was conducted to assess the survival advantage of giving autologous blood instead of allogeneic blood during surgery for esophageal cancer. Methods: We retrospectively analyzed 62 patients who underwent esophagectomy for thoracic esophageal cancer between January 1991 and February 1995 and received allogeneic blood transfusion, and 61 patients operated on between March 1995 and February 1998, who received autologous blood transfusion. The clinicopathological factors and survival rates were compared between the two groups. Results: The clinicopathological factors that influenced prognosis were similar in the two groups; however, a definite survival advantage was evident in the autologous blood transfusion group. According to multivariate analyses, the transfusion of allogeneic blood was an independent prognostic factor (P = 0.0222), as was the presence of metastatic lymph nodes. Patients who received allogeneic blood transfusions perioperatively had more than a twofold greater risk (Hazard ration 2.406) of death over patients who received autologous blood transfusions. Conclusion: Autologous blood transfusion appears to be an independent prognostic factor for the survival of patients with esophageal cancer. Received: August 20, 2001 / Accepted: May 7, 2002 Reprint requests to: S. Motoyama     

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.     

The role of tranexamic acid in a comprehensive blood management protocol for total hip and knee arthroplasty patients

Allogeneic blood transfusions during total hip or knee arthroplasty have been associated with increased risks for perioperative complications as well as increased medical costs. A multi-modal approach toperioperative management of the patients to minimize the risk for an allogeneic blood transfusion can help both the patient and the health care system. This approach involves optimizing the patients’ hemoglobin preoperatively, utilizing a variety of techniques intraoperatively including tranexamic acid to minimize blood loss, and using patient specific transfusion triggers post-operatively. In particular, the incorporation of tranexamic acid to the perioperative management of total hip and total knee replacement patients dramatically decreased the rate of allogeneic blood transfusions in our hospital.     

Aprotinin and tranexamic acid for high transfusion risk cardiac surgery

BACKGROUND: Studies have shown that aprotinin and tranexamic acid can reduce postoperative blood loss after cardiac operation. However, which drug is more efficacious in a higher risk surgical group of patients, has yet to be defined in a randomized study. METHODS: With informed consent, 80 patients undergoing elective high transfusion risk cardiac procedures (repeat sternotomy, multiple valve, combined procedures, or aortic arch operation) were randomized in a double-blind fashion, to receive either high dose aprotinin or tranexamic acid. Patient and operative characteristics, chest tube drainage and transfusion requirements were recorded. RESULTS: There was no significant difference between the 2 treatment groups with respect to age, cardiopulmonary bypass time, complications (myocardial infarction, stroke, death), chest tube drainage (6, 12, or 24 hours), blood transfusions up to 24 hours postoperatively, total allogeneic blood transfusions for entire hospital stay, or induction/postoperative hemoglobin levels. However, multiple regression analysis revealed a positive relationship between cardiopulmonary bypass time and 24 hour blood loss in the tranexamic acid group (p = 0.001), unlike the aprotinin group where 24 hour blood loss is independent of cardiopulmonary bypass time (p = 0.423). CONCLUSIONS: Overall, there was no significant difference in blood loss, or transfusion requirements, when patients received either aprotinin or tranexamic acid for high transfusion risk cardiac operation. Aprotinin, when given as an infusion in a high-dose regimen, was able to negate the usual positive effect of cardiopulmonary bypass time on chest tube blood loss.     

Pharmacologic preservation of the hemostatic system during cardiac surgery.

Bleeding after cardiac surgery remains a major potential problem. Numerous pharmacologic approaches to attenuating hemostatic system activation in cardiac surgery patients have been studied to further improve patient management. Therapeutic approaches studied include inhibiting thrombin generation or activation, preserving platelet function, and decreasing the need for transfusion of allogeneic blood products. Pharmacologic approaches to reduce bleeding and transfusion requirements in cardiac surgery patients are based on either preventing or reversing the defects associated with the CPB-induced coagulopathy. The increasing use of platelet inhibitors (clopidogrel and IIb/IIIa receptor antagonists) and new anticoagulants (low-molecular weight heparins, pentasaccharide, recombinant hirudin, bivalirudin, and argatroban) also pose interesting problems in managing cardiac surgery patients. Aprotinin and lysine analogues (epsilon-aminocaproic acid and tranexamic acid) have become mainstay therapeutic agents to prevent bleeding and the potential need for allogeneic transfusion. Newer therapies that are important to consider include the potential of recombinant activated factor VIIa as a therapy for refractory bleeding after cardiac surgery.     

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.     

Predictors of transfusion requirements for cardiac surgical procedures at a blood conservation center

BACKGROUND: Previous studies defining perioperative risk factors for allogeneic transfusion requirements in cardiac surgery were limited to highly selected cardiac surgery populations or were associated with high transfusion rates. The purpose of this study was to determine perioperative risk factors and create a formula to predict transfusion requirements for major cardiac surgical procedures in a center that practices a multimodality approach to blood conservation. METHODS: We performed an observational study on 307 consecutive patients undergoing coronary artery bypass grafting, valve, and combined (coronary artery bypass grafting and valve) procedures. An equation was derived to estimate the risk of transfusion based on preoperative risk factors using multivariate analysis. In patients with a calculated probability of transfusion of at least 5%, intraoperative predictors of transfusion were identified by multivariate analysis. RESULTS: Thirty-five patients (11%) required intraoperative or postoperative allogeneic transfusions. Preoperative factors as independent predictors for transfusions included red blood cell mass, type of operation, urgency of operation, number of diseased vessels, serum creatinine of at least 1.3 mg/dL, and preoperative prothrombin time. Intraoperative factors included cardiopulmonary bypass time, three or fewer bypass grafts, lesser volume of acute normovolemic hemodilution removed, and total crystalloid infusion of at least 2,500 mL. The derived formula was applied to a validation cohort of 246 patients, and the observed transfusion rates conformed well to the predicted risks. CONCLUSIONS: A multimodality approach to blood conservation in cardiac surgery resulted in a low transfusion rate. Identifying patients' risks for transfusion should alter patient management perioperatively to decrease their transfusion rate and make more efficient use of blood resources.     

Intraoperative low-volume acute normovolemic hemodilution in adult open-heart surgery

BACKGROUND: Recently, various studies have questioned the efficacy of intraoperative acute normovolemic hemodilution (ANH) in reducing bleeding and the need for allogeneic transfusions in cardiac surgery. The aim of the present study was to reevaluate the effects of a low-volume ANH in elective, adult open-heart surgery. METHODS: Two hundred four consecutive adult patients undergoing cardiac surgery were prospectively randomized in a nonblinded manner into two groups: ANH group (103 patients), where 5-8 ml/kg of blood was withdrawn before systemic heparinization and replaced with colloid solutions, and a control group, where no hemodilution was performed (101 patients). Procedures included single and multiple valve surgery, aortic root surgery, coronary surgery combined with valve surgery, or partial left ventriculectomy. The purpose of the study was to evaluate the efficacy of ANH in reducing the need for allogeneic blood components. Routine hematochemical evaluations, perioperative blood loss, major complications, and outcomes were also recorded. RESULTS: No differences were found between the groups regarding demographics, baseline hematochemical data, and operative characteristics. There was no difference in the amount of transfusions of packed red cells, fresh frozen plasma, platelet concentrates, total number of patients transfused (control group, 36% vs. ANH group, 34.3%; P = 0.88), and amount of postoperative bleeding (control group, 412 ml [313-552 ml] vs. ANH group, 374 ml [255-704 ml]) (median [25th-75th percentiles]); P = 0.94. Further, perioperative complications, postoperative hematochemical data, and outcomes were not different. CONCLUSIONS: In patients undergoing elective open-heart surgery, low-volume ANH showed lack of efficacy in reducing the need for allogeneic transfusions and postoperative bleeding.     

Perioperative Blood Management Strategies for Total Knee Arthroplasty

Total knee arthroplasty (TKA) often causes a significant amount of blood loss with an accompanying decline in hemoglobin and may increase the frequency of allogeneic blood transfusion rates. Unfortunately, allogeneic blood transfusions have associated risks including postoperative confusion, infection, cardiac arrhythmia, fluid overload, increased length of hospital stay, and increased mortality. Other than reducing the need for blood transfusions, reducing perioperative blood loss in TKA may also minimize intra‐articular hemorrhage, limb swelling, and postoperative pain, and increase the range of motion during the early postoperative period. These benefits improve rehabilitation success and increase patients’ postoperative satisfaction. Preoperative anemia, coupled with intraoperative and postoperative blood loss, is a major factor associated with higher rates of blood transfusion in TKA. Thus, treatment of preoperative anemia and prevention of perioperative blood loss are the primary strategies for perioperative blood management in TKA. This review, combined with current evidence, analyzes various methods of blood conservation, including preoperative, intraoperative, and postoperative methods, in terms of their effectiveness, safety, and cost. Because many factors can be controlled to reduce blood loss and transfusion rates in TKA, a highly efficient, safe, and cost‐effective blood management strategy can be constructed to eliminate the need for transfusions associated with TKA.     

A meta-analysis of the effectiveness of cell salvage to minimize perioperative allogeneic blood transfusion in cardiac and orthopedic surgery. International Study of Perioperative Transfusion (ISPOT) Investigators.

Concern about risks of allogeneic transfusion has led to an interest in methods for decreasing perioperative transfusion. To determine whether cell salvage reduces patient exposure to allogeneic blood, we performed meta-analyses of randomized trials, evaluating the effectiveness and safety of cell salvage in cardiac or orthopedic elective surgery. The primary outcome was the proportion of patients who received at least one perioperative allogeneic red cell transfusion. Twenty-seven studies were included in the meta-analyses. Cell salvage devices that do not wash salvaged blood were marginally effective in cardiac surgery patients when used postoperatively (relative risk [RR] = 0.85, 95% confidence interval [CI] = 0.79-0.92). Devices that wash or do not wash salvaged blood considerably decreased the proportion of orthopedic surgery patients who received allogeneic transfusion (RR = 0.39, 95% CI = 0.30-0.51 and RR = 0.35, 95% CI 0.26-0.46, respectively). No studies of cell savers that wash salvaged blood during cardiac surgery were included. Cell salvage did not appear to increase the frequency of adverse events. We conclude that cell salvage in orthopedic surgery decreases the risk of patients' exposure to allogeneic blood transfusion perioperatively. Postoperative cell salvage in cardiac surgery, with devices that do not wash the salvaged blood, is only marginally effective. IMPLICATIONS: This meta-analysis of all published randomized trials provides the best current estimate of the effectiveness of cell salvage and is useful in guiding clinical practice. We conclude that cell salvage in orthopedic surgery decreases the proportion of patients requiring allogeneic blood transfusion perioperatively, but postoperative cell salvage is only marginally effective in cardiac surgery.