Aprotinin in major orthopedic surgery: a systematic review of randomized controlled trials

Aprotinin therapy is a promising strategy for reducing blood loss and blood transfusion requirements. The efficacy and safety of aprotinin in orthopedic surgery, however, remain controversial. We searched electronic databases for randomized controlled trials on the efficacy and safety of the use of aprotinin in orthopedic surgery. Thirteen trials that included a total of 506 patients who underwent major orthopedic surgery were analyzed. The pooled intraoperative and perioperative blood loss was significantly less in the aprotinin-treated patients than in the control patients (weighted mean difference [WMD] for intraoperative blood loss = -229 mL, 95% confidence interval [CI] = -367 to -91 mL, P = 0.0011; WMD for perioperative blood loss = -557 mL; 95% CI = -860 to -254 mL; P < 0.0001). The pooled amounts of red blood cell (RBC) units (U) transfused intraoperatively and perioperatively were significantly less in the aprotinin-treated patients than in the control patients (WMD for intraoperative RBC U = -1.1 U; 95% CI = -1.7 to -0.4 U; P = 0.0001; WMD for perioperative RBC U = -1.1 U; 95% CI = -1.7 to -0.5 U; P < 0.0001). Aprotinin was not associated with an increased incidence of deep vein thrombosis (odds ratio = 0.39; 95% CI = 0.14 to 1.05, P = 0.061). The authors conclude that aprotinin reduces the intraoperative and perioperative blood loss and allogeneic blood transfusion requirement and may not be associated with increased risk of deep vein thrombosis in the presence of pharmacological or mechanical prophylaxis in patients undergoing major orthopedic surgery.     

Identification of risk factors for allogenic transfusion in cardiac surgery from an observational study

OBJECTIVE: To determine perioperative variables for predicting allogenic transfusion in adult cardiac surgery. STUDY DESIGN: Prospective study. PATIENTS: We included 335 consecutive patients undergoing cardiac surgery between February and April 2001. METHODS: Perioperative variables were prospectively collected in a database. For each patient who received transfusion, hemoglobin threshold for transfusion and total number of units of red cell concentrates were collected. Univariate and multivariate analysis were performed. RESULTS: The two strategies for blood conservation which were predominantly used were aprotinin therapy (78%) and blood salvage from the extracorporeal circuit (68%). During perioperative period, 42% of patients [95% CI: 37-47%] received allogenic transfusion. The haemoglobin threshold for transfusion was 7.4 +/- 1.1 and 8.0 +/- 0.7 g x dl(-1) in operating room and in intensive care unit, respectively. On average, 3.4 +/- 2.7 units of red cell concentrates were transfused perioperatively per patient. Using multivariate analysis, perioperative allogenic transfusion was significantly associated with the following variables: preoperative haemoglobin level < 12 g x dl(-1) (odds ratio 8.9; p = 0.001), emergency procedure (odds = 3.7, p = 0.01), reoperation (odds ratio = 3.3; p = 0.002), chronic obstructive pulmonary disease (odds ratio = 2.5; p = 0.03) and complex surgery (odds ratio = 2.4; p = 0.01). The age, the gender, and body mass index were only independent risk factors by univariate analysis. CONCLUSION: In despite of techniques to limit requirement of allogenic transfusion, a large proportion of cardiac surgical patients remains transfused. Independent risk factors of perioperative transfusion are haemoglobin level < 12 g x dl(-1), emergency procedure, reoperation, chronic obstructive pulmonary disease and complex 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.     

关于心脏手术中自体血回收有效性随机试验的荟萃分析

背景在心脏手术中可以通过自体血回收来避免输注同种异体血。另外已有人提出,血液中的碎片可能会增加卒中或神经意识功能障碍的风险,因此,清除回收血中的碎片可改善患者的预后。在此研究中,我们试图通过系统性回顾已发表的随机控制性试验进行荟萃分析,明确在心脏手术中自体血回收的整体安全性和有效性。方法全面检索找出关于所有有关心脏手术中应用自体血回收技术的所有随机试验。截止到2008年11月的MEDLINE、Cochrane图书馆、EMBASE和摘要资料库均被检索完全。将所有心脏手术中应用自体血回收技术与未应用自体血回收技术进行比较,并且报道至少一个明确的临床结果的随机试验均被列为研究对象。随机效应模型被用来依次计算比值比（OR,95％可信区间）、二分法加权平均差（WMD,95％可信区间）和连续变量。结果包括2282例患者在内的31个随机试验最终被作为研究对象进行荟萃分析。在心脏手术中,进行手术中自体血回收减少了接触同种异体异基因血制品（比值比0．63,95％可信区间：0．43—0．94,P=0．02）及红细胞（比值比0．60,95％可信区间：0．39—0．92,P=0．02）的概率,也降低了平均每例患者输注同种异体异基因血制品的总量（加权平均差-256ml,95％可信区间：-416--95ml,P=0．002）。但在以下几个方面进行自体血回收组与未进行自体血回收组之间并无差异,包括：院内死亡率（比值比0．65,95％可信区间：0．25—1．68,P=0．37）、手术后卒中或短暂缺血性发作（比值比0．59,95％可信区间：0．20～1．76,P=0．34）、房颤（比值比0．92,95％可信区间：0．69—1．23,P=0．56）、肾功能衰竭（比值比0．86,95％可信区间：0．41—1．80,P=0．70）、感染（比值比1．25,95％可信区间：0．75—2．10,P=0．39）、接受新鲜冰冻血浆治疗（比值比1．16,95％可信区间：0．82—1．66,P=0．40）以及接受血小板输注治疗（比值比0．90,95％可信区间：0．63—1．28,P=0．55）。结论现有的证据表明应用自体血回收技术可减少心脏手术中患者异体血制品或红细胞的输注。进一步的分析认为,只有在收集失血和（或）剩余机血,或在整个手术过程中应用自体血回收技术才是有利的。如果只在体外循环期间用自体血回收技术作为心内吸引,则对于血液保护没有明显效应且增加新鲜冰冻血浆的输注。     

Intraoperative autologous blood salvage with cardiac surgery: an analysis of five years' experience in more than 3,000 patients.

STUDY OBJECTIVE: To analyze intraoperative autologous salvage of shed mediastinal blood and subsequent transfusion in cardiac surgery. DESIGN: Retrospective statistical analysis. SETTING: University hospital. PATIENTS: Three thousand twenty two patients undergoing cardiac surgery from 1984 to 1988. INTERVENTIONS: A review of anesthesia and transfusion records of all patients who underwent intraoperative salvage of shed blood and autologous transfusion using the Sorenson Receptal Auto Transfusion System (ATS) with saline wash prior to reinfusion in cardiac surgery. MEASUREMENTS AND MAIN RESULTS: The salvaged blood volume ranged from 36 to 2,795 ml, with a mean of 321 +/- 222 ml (SD). Eighteen percent of patients did not receive any homologous blood products during their hospitalization. Patients who received only salvaged autologous transfusion were younger, had higher preoperative hemoglobin and hematocrit values, had a larger body surface area, and had shorter surgeries compared with patients who received only homologous blood or both autologous and homologous blood. More blood products were given to patients who received salvaged autologous blood compared with those who did not. Patients who underwent normovolemic hemodilution prior to extracorporeal circulation with subsequent reinfusion received significantly fewer blood products. Ten preoperative and four intraoperative variables significantly influenced the salvaged volume. Previous cardiac surgery was the most significant preoperative variable, and repair of ventricular septal defect produced by myocardial ischemia was the most significant intraoperative variable. CONCLUSION: Considering the average salvaged volume and its current autologous transfusion-related expense, autologous blood salvage is potentially an economic benefit. Perioperative blood conservation requires a considerable commitment from surgeons, anesthesiologists, perfusionists, and intensive care physicians to be effective.     

Cell salvage does not minimize perioperative allogeneic blood transfusion in abdominal vascular surgery: a systematic review

PURPOSE: To determine whether the use of cell salvage reduces the proportion of patients receiving at least one unit of allogeneic packed red blood cells during the perioperative period of an elective vascular surgery. SOURCE: We identified all relevant articles through the combined use of electronic searches of the MEDLINE and EMBASE databases, the Cochrane library as well as hand searching of all randomized clinical trials and review articles. The electronic search included articles published between 1966 and April 2001. The search included textword searches using "autotransfusion," "cell salvage," "device," or Medical Subject Headings "autologous blood transfusion" or a "randomized controlled trials" filter. PRINCIPAL FINDINGS: Five randomized controlled trials (RCT) were identified involving cell salvage and vascular surgeries. In infra renal abdominal aortic aneurysm surgery the risk ratio (the risk of receiving at least one unit of allogeneic red cells) was 0.37 [95% confidence intervals (CI) of 0.06 to 2.36]. In elective aorto-femoral bypass surgery the risk ratio was 0.97 (95% CI of 0.66 to 1.42). The pooled risk ratio for cell salvage in vascular surgery was 0.67 (95% CI of 0.35 to 1.28). CONCLUSION: Cell salvage, a commonly used technique to recover red cells from the operative field, has been the subject of several studies in vascular surgery. There is insufficient evidence to recommend the routine use of cell salvage in elective abdominal aortic aneurysm and aorto-femoral bypass surgeries. A large RCT would elucidate whether cell salvage is effective as a blood conservation technique.     

Perioperative blood salvage as an alternative to predonating blood for primary total knee and hip arthroplasty

A total of 200 consecutive patients who underwent primary total knee or hip arthroplasty were reviewed to assess the efficacy of perioperative blood salvage and retransfusion. Five of 132 (3.8%) patients undergoing total knee arthroplasty and 3 of 68 (4.4%) patients undergoing total hip arthroplasty required allogeneic transfusion in addition to retransfusion of salvaged autologous blood. The risk of receiving allogeneic transfusion in addition to retransfusion of salvaged blood was 1.2% (2 of 173) in patients with a preoperative hematocrit of > or=37%. The risk of requiring allogeneic transfusion was 22% (6 of 27) in patients with a preoperative hematocrit of 37%.     

Effects of cardiopulmonary bypass circuit reduction and residual volume salvage on allogeneic transfusion requirements in infants undergoing cardiac surgery

Cardiopulmonary bypass in children may cause severe hemodilution and can lead to excessive perioperative blood loss and high transfusion requirements. Minimization of cardiopulmonary bypass circuit and salvage of red blood cells from the residual volume after the procedure are widely utilized to reduce allogeneic transfusion. We evaluated the effectiveness of those measures introduced in infant cardiac surgery in our institution. This retrospective observational study included 148 consecutive infants between 1 and 12 months of age, with a body weight <10 kg, who underwent an elective cardiac operation between 1997 and 2005. Patients were divided into three groups defined by the circuit prime volume; 700 ml (Group 1), 450 ml (Group 2) and 330 ml (Group 3). In Group 1 residual volume after perfusion was discarded and in Groups 2 and 3 was processed in a cell saving device. Analyzed variables were: perioperative blood loss, transfusion of homologous blood products and cell salvage product, and hematology data. Reduction of the circuit volume significantly diminished use of red blood cell concentrates from 1.6 units to 0.8 units (P<0.0001), and fresh frozen plasma from 1.3 units to 0.4 units (P<0.0001). Utilization of the cell salvage product reduced significantly (P=0.023) the postoperative need for homologous blood transfusion. Therefore, both measures proved to be effective in reducing homologous blood transfusion in infant cardiac surgery.     

Blood salvage in total hip and knee arthroplasty in a community hospital: a retrospective study

PURPOSES: To assess the results of postoperative and intra-operative blood salvage in patients undergoing total knee and hip arthroplasty, respectively, and to determine if both methods of blood salvage reduce allogeneic transfusion. METHODS: Of 229 patients who attempted blood salvage, 114 of 152 patients who underwent total knee arthroplasty received the salvaged blood postoperatively, 35 of 77 patients who underwent total hip arthroplasty received the salvaged blood intra-operatively. Various data were collected to assess whether certain factors resulted in autologous and/or allogeneic blood transfusions. RESULTS: Patients that received postoperative salvaged blood after total knee arthroplasty generally had higher postoperative levels of haemoglobin and haematocrit compared to those who did not. Patients with autologous blood transfusion following cemented knee surgery were less likely to require allogeneic blood transfusion. For hip arthroplasty patients, postoperative levels of haemoglobin and haematocrit were similar in both groups who received and did not receive salvaged blood. Lower preoperative haemoglobin and haematocrit levels correlated with a greater likelihood of autologous and/or allogeneic blood transfusion for both knee and hip arthroplasty patients. CONCLUSIONS: Although total knee arthroplasty patients who received salvaged blood had higher haemoglobin levels on the first postoperative day, the receipt of salvaged blood did not significantly reduce the incidence of allogeneic blood transfusion, because salvaged blood was a kind of blood loss. However, reinfusion of salvaged blood may reduce the number of units of allogeneic blood used. Given the short supply of allogeneic blood and its risks of transmitting disease, intra-operative and postoperative blood salvage carries clear advantages.     

Alternative Procedures for Reducing Allogeneic Blood Transfusion in Elective Orthopedic Surgery

Perioperative blood loss is a major problem in elective orthopedic surgery. Allogeneic transfusion is the standard treatment for perioperative blood loss resulting in low postoperative hemoglobin, but it has a number of well-recognized risks, complications, and costs. Alternatives to allogeneic blood transfusion include preoperative autologous donation and intraoperative salvage with postoperative autotransfusion. Orthopedic surgeons are often unaware of the different pre- and intraoperative possibilities of reducing blood loss and leave the management of coagulation and use of blood products completely to the anesthesiologists. The goal of this review is to compare alternatives to allogeneic blood transfusion from an orthopedic and anesthesia point of view focusing on estimated costs and acceptance by both parties.     

Use of a leucocyte filter to remove tumour cells from intra‐operative cell salvage blood

The intra‐operative blood loss of 50 consecutive gynae‐oncology patients undergoing surgery for endometrial, cervical or ovarian cancer was cell salvaged and filtered. In each case blood samples were taken from the effluent tumour vein, a central venous line, the cell saver reservoir, the cell salvage re‐transfusion bag after processing but before filtration and from the cell salvage re‐transfusion bag after processing and filtration. Samples were examined using immunohistochemical monoclonal antibody markers for epithelial cell lines. Viable, nucleated malignant cells were detected in 2/50 central venous samples, 34/50 reservoir samples and 31/50 unfiltered cell salvaged samples. After passage through a Pall RS leucocyte depletion filter no remaining viable, nucleated malignant cells were detected in any sample. The clinical risks of cell salvage in these circumstances should be reviewed in the light of the risks of allogeneic blood transfusion.     

Intraoperative cell salvage in infants undergoing elective cardiac surgery: a prospective trial

BACKGROUND: For a long time intraoperative cell salvage was considered not to be applicable in paediatric patients due to technical limitations. Recently, new autotransfusion devices with small volume centrifugal bowls and dedicated paediatric systems allow efficient blood salvage in small children. The purpose of this prospective non-randomised study was to determine the impact of intraoperative cell salvage on postoperative allogeneic blood products transfusion in infant patients undergoing cardiac surgery with cardiopulmonary bypass. METHODS: Two consecutive cohorts (122 patients) were studied. The first cohort underwent procedures between January 2004 and July 2005 with only blood salvage from the residual volume. The second cohort consisted of patients operated on from August 2005 to December 2006, with additional use of intraoperative cell salvage. The following variables were analysed: peri- and postoperative blood loss, transfusion of homologous blood products and cell salvage product, haematological and coagulation data, measured before, during and after the operation. RESULTS: Additional intraoperative cell salvage significantly enhanced the amount of cell saving product available for transfusion (183+/-56 ml vs 152+/-57 ml, p=0.003) and significantly more patients in this group received the cell saving product postoperatively. Consequently, allogeneic blood transfusion was significantly reduced in volume as well as in frequency. We did not observe any adverse effects of intraoperative cell salvage. CONCLUSION: Intraoperative cell salvage, employed as an adjuvant technique to the residual volume salvage in infants undergoing first time cardiac surgery with cardiopulmonary bypass, was a safe and effective method to reduce postoperative allogeneic blood transfusion. Considering current cell salvage related expense and the cost reduction achieved by diminished allogeneic transfusion, intraoperative cell salvage in infants demonstrated no economic benefit.     

心脏外科手术中应用自体血回收技术的血液保护效果Meta分析

目的 采用Meta分析评价心脏外科手术中应用血液回收技术的血液保护效果. 方法 计算机检索Cochrane 图书馆、PubMed、Embase、CINAHL以及中国知网数据库.收集关于心脏外科手术使用自体血回收的随机对照试验,按Cochrane 系统评价方法,评价所纳入研究的文献质量,并提取有效数据后采用RevMan 5.1软件进行Meta分析. 结果 纳入11项研究,共计2 046例患者.与对照组比较,应用血液回收技术能够减少围手术期红细胞的使用率[比值比(odda radio,OR)=0.68,95％置信区间(confidence interval,CI)(O.53,0.87)],减少围手术期新鲜冰冻血浆的使用率[OR=1.53,95％CI(1.02,2.31)],围手术期血小板的使用率差异无统计学意义[0R=0.86,95％CI (0.56,1.32)],术后并发症的发生率差异无统计学意义[OR=1.14,95％CI(0.92,1.41)]. 结论 心脏手术中使用自体血回收技术可以减少红细胞和新鲜冰冻血浆的输注,具有一定的血液保护效果,且不会增加术后并发症的发生率.     

Do antifibrinolytics reduce allogeneic blood transfusion in orthopedic surgery?

Studies have shown that antifibrinolytic (aprotinin, tranexamic acid, epsilon-aminocaproic acid) reduce blood loss in orthopedic surgery. However, most lacked sufficient power to evaluate the efficacy and safety on clinical outcomes. This meta-analysis aims to evaluate whether intravenous antifibrinolytics, when compared with placebo, reduce perioperative allogeneic erythrocyte transfusion requirement in adults undergoing orthopedic surgery and whether it might increase the risk of venous thromboembolism. From MEDLINE, EMBASE, and the Cochrane Controlled Trials Register, the authors identified 43 randomized controlled trials in total hip and knee arthroplasty, spine fusion, musculoskeletal sepsis, or tumor surgery performed to July 2005 (for aprotinin, 23 trials with 1,268 participants; tranexamic acid, 20 with 1,084; epsilon-aminocaproic acid, 4 with 171). Aprotinin and tranexamic acid reduced significantly the proportion of patients requiring allogeneic erythrocyte transfusion according to a transfusion protocol. The odds ratio was 0.43 (95% confidence interval, 0.28-0.64) for aprotinin and 0.17 (0.11-0.24) for tranexamic acid. Results suggest a dose-effect relation with tranexamic acid. Epsilon-aminocaproic acid was not efficacious. Unfortunately, data were too limited for any conclusions regarding safety. Although the results suggest that aprotinin and tranexamic acid significantly reduce allogeneic erythrocyte transfusion, further evaluation of safety is required before recommending the use of antifibrinolytics in orthopedic surgery.     

A prospective randomized study comparing two techniques of perioperative blood conservation: isovolemic hemodilution and hypervolemic hemodilution

We compared hypervolemic hemodilution (HVH) and isovolemic hemodilution (IVH) as means of perioperative blood conservation under standardized conditions. Thirty ASA status I/II adults slated for orthopedic, ear-nose-throat, or general surgery with expected blood loss of >500 mL underwent either IVH (n = 15) or HVH (n = 15). They were hemodiluted to a hematocrit (Hct) of 25% by blood withdrawal and simultaneous polygeline (Hemaccel((R))) infusion (IVH) or by infusing polygeline without blood withdrawal, thus creating hypervolemia (HVH). Further blood loss to a Hct of 20% was allowed before autologous/allogeneic blood transfusion to aim for a 24-h postoperative Hct of > or =25%. Systolic blood pressure (P = 0.0107) and central venous pressure (P = 0.0281) were significantly higher during HVH. The mean difference (MD) between the target postdilution Hct of 25% and the Hct achieved was not statistically significant in either group (MD [95% confidence interval; CI], 0% [-0.7% to 0.7%] for IVH and 0.6% [-0.1% to 1.3%] for HVH). The actual amount of allogeneic blood used was similar in the two groups, with an MD (95% CI) of -7 (-326 to 312), and was significantly less than the corresponding projected amount (MD [95% CI], -581 mL [-753 to -409 mL] in IVH; -376 mL [-531 to -221] in HVH). The two techniques were similar in time taken (MD [95% CI] = 7 min [-0.5 to 14.5 min]), cost incurred (MD [95% CI] = $1.7 (-$4.10 to $7.50]), and volumes of polygeline used (MD [95% CI] = -6 mL/kg body weight [-16 to 4 mL/kg body weight]). This study found IVH and HVH comparable in significantly reducing perioperative allogeneic blood requirements, time needed, and cost incurred. The formula used for achieving the desired HVH appears promising. IMPLICATIONS: Both hypervolemic hemodilution (HVH) and isovolemic hemodilution (IVH) claim to reduce red blood cell loss during surgery by diluting the patient's blood. This study found both comparable in significantly reducing the exposure to bank blood in the perioperative period, the time needed, and the cost incurred. HVH, being simpler, because it does not involve blood withdrawal, appeared superior to IVH in the healthy adults studied. Larger studies are needed to substantiate the results.     

Incidence and risk factors for allogenic blood transfusion during major joint replacement using an integrated autotransfusion regimen. The Rizzoli Study Group on Orthopaedic Anaesthesia

The efficacy of an integrated autotransfusion regimen, including pre-donation and perioperative salvage of autologous blood, was prospectively evaluated in 2884 patients undergoing total hip (n = 2016) or knee arthroplasty (n = 480), and hip revision (n = 388) with either balanced general, regional, or integrated epidural/general anaesthesia. Allogenic concentrated red blood cells were transfused in the presence of symptomatic anaemia or when haemoglobin concentration was < 6 g dL-1 (10 g dL-1 in patients affected by cerebrovascular or coronary artery disease) after all salvaged and pre-donated autologous blood had been transfused. A total of 278 patients (9.6%) received allogenic blood. Risk factors for allogenic blood transfusion were: preoperative haemoglobin concentration < 10 g dL-1 (after autologous blood pre-donations) (Odds ratio: 8.7; 95% CI: 6.5-16.8; P = 0.004), hip revision versus hip or knee arthroplasty (Odds ratio: 5.8; 95% CI: 3.9-8.5; P = 0. 0001) and inability in obtaining the number of pre-donations required by the Maximum Surgery Blood Order on Schedule (Odds ratio: 3.4; 95% CI: 2.7-4.1; P = 0.0001). The incidence of perioperative complications, including wound infection and haematoma, as well as myocardial ischaemia, respiratory failure and thromboembolic complications, was higher in those patients requiring allogenic blood transfusion (29.8%) than that observed in patients receiving only autologous blood (6.6%) (P = 0.0005); while the mean time duration from surgical procedure to patient discharge from the orthopaedic ward was shorter in those patients not receiving allogenic blood transfusion (12 days; 25-75th percentiles: 8-14 days) than in those patients who required perioperative transfusion with allogenic blood (15 days; 25-75th percentiles: 10-17 days) (P = 0.0005). In conclusion, this prospective study highlighted the clinical relevance of applying an extensive and integrated autotransfusion regimen in order to reduce allogenic blood transfusion and associated complications in patients undergoing major joint replacement.     

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.     

全自动自体血液回收系统在大血管外科手术中的应用

目的　介绍全自动血液回收系统在复杂大血管手术中应用的经验。　方法　６ 例动脉瘤和１ 例肝血管瘤手术患者,在全身麻醉下行人造血管置换或动脉瘤部分切除术,在手术开始或体外循环结束时,启用全自动血液回收系统,回收术野的出血或渗血,进行浓缩、洗涤后,再回输入体内,并按回收浓缩洗涤回输程序重复进行。　结果　７ 例患者平均回收血量３ １０７ｍｌ（１ ３００８ ５００ ｍｌ） ,洗涤红细胞１ １２５ｍｌ（６７５２ ９２５ｍｌ） 。平均输注佳乐施或海脉素２ ０００ｍｌ,２ 例术中输入全血和血浆,术中血流动力学稳定。术后如期出院。　结论　复杂的大血管手术应用全自动血液回收系统具有广泛的适应证,是节约用血、减少输用库血的可靠方法。     

Reducing allogeneic transfusion in cardiac surgery: a randomized double-blind placebo-controlled trial of antifibrinolytic therapies used in addition to intra-operative cell salvage

Background. The transfusion of allogeneic red blood cells andallogeneic coagulation products is associated with risk to thepatient and the depletion of an increasingly scarce resource.This prospective, randomized, double-blind, placebo-controlledtrial investigated practices to avoid transfusion in patientsundergoing first-time cardiac surgery. Methods. Patients were randomized to one of three treatmentgroups: an aprotinin group, a tranexamic acid group, and a controlgroup receiving normal saline. Intra-operative cell salvagewas used for all patients. The primary outcomes were the numberof patients exposed to allogeneic red blood cells, allogeneiccoagulation products or any allogeneic transfusion (allogeneicred blood cells and/or allogeneic coagulation products). Results. Patients were 2.5 times more likely to receive anyallogeneic transfusion in the tranexamic group than in the aprotiningroup (21 patients out of 60 compared with nine out of 60, respectively).The relative risk of any allogeneic transfusion comparing aprotininwith tranexamic acid was 0.43 (95% confidence interval 0.21–0.86;P=0.019). Patients in the control group were four times morelikely to receive any allogeneic transfusion when compared withthe aprotinin group (37 patients out of 60 compared with nineout of 60, respectively). The relative risk of any allogeneictransfusion comparing aprotinin with control was 0.24 (95% confidenceinterval 0.13–0.46; P<0.001). Conclusions. When used in addition to intra-operative cell salvage,aprotinin is the most efficacious pharmacological therapy forreducing patient exposure to any allogeneic transfusion duringfirst-time cardiac surgery.