Need For Allogeneic Blood Products Research Articles

Protocol for a phase 3, randomised, active-control study of four-factor prothrombin complex concentrate versus frozen plasma in bleeding adult cardiac surgery patients requiring coagulation factor replacement: the LEX-211 (FARES-II) trial

IntroductionReduced thrombin generation is an important component of post cardiopulmonary bypass (CPB) coagulopathy. To replenish coagulation factors and enhance thrombin generation in bleeding surgical patients, frozen plasma (FP) and four-factor...

Perioperative blood conservation strategies for pediatric scoliosis surgery.

Many pediatric patients with severe scoliosis requiring surgery have baseline anemia. Pediatric scoliosis fusion surgery is associated with perioperative blood loss requiring transfusion. As such, many patients in this surgical population could benefit from a perioperative blood conservation program. Here we present a narrative review of perioperative blood conservation strategies for pediatric scoliosis surgery involving nurses, transfusion medicine physicians, anesthesiologists, surgeons, dieticians, perfusionists and neurophysiologists spanning the pre-, intra- and postoperative phases of care. The review highlights how perioperative blood conservation strategies, have the potential to minimize exposures to exogenous blood products. Further, we describe a relevant example of blood conservation related to the care of a Jehovah's Witness patient undergoing staged scoliosis repair. Lastly, we outline areas which would benefit from clinical studies to further elucidate perioperative blood conservation interventions and their outcomes relevant to pediatric scoliosis surgery patients. Interdisciplinary communication and meticulous blood conservation strategies are proving to be a means of reducing if not eliminating the need for allogeneic blood products for surgical correction of pediatric scoliosis.

The safety and efficiency of intravenous administration of tranexamic acid in coronary artery bypass grafting (CABG): a meta-analysis of 28 randomized controlled trials

BackgroundThe safety and efficiency of intravenous administration of tranexamic acid (TXA) in coronary artery bypass grafting (CABG) remains unconfirmed. Therefore, we conducted a meta-analysis on this topic.MethodsWe searched the Cochrane Central Register of Controlled Trials (CENTRAL), PUBMED and EMBASE for randomized controlled trials on the topic. The results of this work are synthetized and reported in accordance with the PRISMA statement.ResultsTwenty-eight studies met our inclusion criteria. TXA reduced the incidence of postoperative reoperation of bleeding (relative risk [RR], 0.46; 95% confidence interval [CI]; 0.31–0.68), the frequency of any allogeneic transfusion (RR, 0.64; 95% CI, 0.52–0.78) and the postoperative chest tube drainage in the first 24 h by 206 ml (95% CI − 248.23 to − 164.15). TXA did not significantly affect the incidence of postoperative cerebrovascular accident (RR, 0.93; 95%CI, 0.62–1.39), mortality (RR, 0.82; 95%CI, 0.53–1.28), myocardial infarction (RR, 0.90; 95%CI, 0.78–1.05), acute renal insufficiency (RR, 1.01; 95%CI, 0.77–1.32). However, it may increase the incidence of postoperative seizures (RR, 6.67; 95%CI, 1.77–25.20). Moreover, the subgroup analyses in on-pump and off-pump CABG, the sensitivity analyses in trials randomized more than 99 participants and sensitivity analyses that excluded the study with the largest number of participants further strengthened the above results.ConclusionsTXA is effective to reduce reoperation for bleeding, blood loss and the need for allogeneic blood products in patients undergoing CABG without increasing prothrombotic complication. However, it may increase the risk of postoperative seizures.

Perioperative Management of a Child with Hypoplastic Left Heart Syndrome of the Jehovah's Witness Faith Presenting for Hybrid Comprehensive Stage II Procedure

Over the years, there has been a growing recognition of the potential negative sequelae of allogeneic blood products on postoperative outcomes following cardiac surgery. In addition, followers of the Jehovah's Witness (JW) faith have a religious restriction against receiving blood or blood components. Advances in perioperative care, cardiopulmonary bypass (CPB), and surgical technique have minimized the need for allogeneic blood products. Specific blood conservation strategies include maximizing the preoperative hematocrit and coagulation function as well as intraoperative strategies, such as acute normovolemic hemodilution and adjustments of the technique of CPB. We report a 7-month-old patient whose parents were of the JW faith who underwent a comprehensive stage II procedure for hypoplastic left heart syndrome without exposure to blood or blood products during his hospital stay. Perioperative techniques for blood avoidance are discussed with emphasis on their application to infants undergoing surgery for congenital heart disease.

Eliminating the use of allogeneic blood products in adolescent idiopathic scoliosis surgery.

The aim of this study was to compare transfusion requirements in patients before and after the introduction of tranexamic acid as standard in patients undergoing spinal surgery for idiopathic scoliosis in a national orthopaedic hospital. A retrospective chart review of 56 idiopathic scoliosis patients who underwent posterior spinal instrumentation and fusion between 2009 and 2013 at our institution. Preoperative, intraoperative, and postoperative data were measured. Patients who received tranexamic acid as standard (n = 31) showed a trend towards a decrease in transfusion requirements compared with those who received no tranexamic acid (n = 25). These patients had a statistically significant decrease in operative time (223 vs 188 min, p = 0.005), and estimated intraoperative blood loss was reduced by nearly 50% in the tranexamic acid group. They also had an associated reduced decrease in haemoglobin between preoperative and postoperative levels (4 vs 5 g/dL, p = 0.01). Since February 2012, no patient has required intraoperative or postoperative allogeneic blood product transfusion in this hospital. The routine use of antifibrinolytic medications in patients undergoing surgery for adolescent idiopathic scoliosis has effectively eliminated the need for allogeneic blood products.

Efficacy of argatroban in critically ill patients with heparin resistance: a retrospective analysis.

The patients who do not respond even to very high dosages of heparin are assumed to suffer from heparin resistance. The aim of this study was to investigate whether critically ill patients suffering from heparin resistance generally have low antithrombin III (AT) levels, and if the direct thrombin inhibitor argatroban in that case can be an effective option to achieve prophylactic anticoagulation. The study was conducted at the Department for General and Surgical Intensive Care Medicine at the University Hospital Innsbruck. We retrospectively included all patients between 2008 and 2012, who received argatroban because of poor response to high-dosage heparin prophylaxis. The period under observation lasted in total for 9 days, 2 days of anticoagulation with unfractionated heparin (UFH) and 7 days with argatroban. The primary objective was to investigate if after 7 (± 1) hours of switching to argatroban the activated partial thromboplastin time (aPTT) levels were in a prophylactic range of 45 to 55 seconds. Further objectives were to assess the AT level, side effects such as bleeding or thromboembolism, platelet count, correlation between organ function and argatroban dose as well as any need for allogeneic blood products. The study population, consisting of 5 women and 15 men with a mean (± standard deviation, SD) age of 54.6 ± 16.3 years, differed in many clinical aspects. A median (interquartile range) heparin dose of 1,000, 819 to 1,125 IU/h was administered for 2 days and failed in providing a prophylactic anticoagulation measured by the aPTT. The mean aPTT level with heparin treatment was 38.5 seconds (± 4.7) its change within that period was not significant. After switching to argatroban, the mean increase of the aPTT levels in all study patients amounted from 38.5 to 48.3 seconds (p < 0.001). The rise in aPTT clearly reaches sufficient prophylactic anticoagulant levels. The maintenance of prophylactic aPTT levels was achieved over the period of 1 week. There was neither a correlation found between low-AT levels and occurrence of heparin resistance, nor between the simplified acute physiology score II and the administered argatroban dose (r = -0.224, p = 0.342). The results of the present study indicate that argatroban is an effective alternative therapy, especially in critically ill patients, to achieve prophylactic anticoagulation when heparin resistance occurs.

A prospective, open-label trial of clevidipine for controlled hypotension during posterior spinal fusion.

Controlled hypotension is one means to limit or avoid the need for allogeneic blood products. Clevidipine is a short-acting, intravenous calcium channel antagonist with a half-life of 1 to 3 minutes due to rapid metabolism by non-specific blood and tissue esterases. To date, there are no prospective evaluations with clevidipine in the pediatric population. We prospectively evaluated the dosing requirements, efficacy, and safety of clevidipine for ontrolled hypotension during spinal surgery for neuromuscular scoliosis in the pediatric population. Patients undergoing posterior spinal fusion for neuromuscular scoliosis were eligible for inclusion. The study was an open label, observational study. Maintenance anesthesia included desflurane titrated to maintain a bispectral index at 40 to 60 and a remifentanil infusion. Motor and somatosensory evoked potentials were monitored intraoperatively. When the mean arterial pressure (MAP) was ≥ 65 mmHg despite remifentanil at 0.3 mcg/kg/min, clevidipine was added to maintain the MAP at 55 to 65 mmHg. Clevidipine was initiated at 0.25 to 1 mcg/kg/min and titrated up in increments of 0.25 to 1 mcg/kg/min every 3 to 5 minutes to achieve the desired MAP. The study cohort included 45 patients. Fifteen patients (33.3%) did not require a clevidipine infusion to maintain the desired MAP range, leaving 30 patients including 13 males and 17 females for analysis. These patients ranged in age from 7.9 to 17.4 years (mean ± SD: 13.7 ± 2.2 years) and in weight from 18.9 to 78.1 kg (mean ± SD: 43.4 ± 14.2 kg). Intraoperatively, the clevidipine infusion was stopped in 6 patients as the surgeon expressed concerns regarding spinal cord perfusion and requested a higher MAP than the study protocol allowed. The data until that point were included for analysis. The target MAP was initially achieved at a mean time of 8.9 minutes. Sixteen of the 30 patients (53.3%) achieved the target MAP within 5 minutes. Heart rate (HR) increased from a baseline of 83 ± 16 to 86 ± 15 beats per minute (mean ± SD) (p=0.04) with the administration of clevidipine. No patient had a HR increase ≥ 20 beats per minute or required the administration of a β-adrenergic antagonist. The duration of the clevidipine administration varied from 8 to 527 minutes (mean ± SD: 160 ± 123 minutes). The maintenance infusion rate of clevidipine varied from 0.25 to 5.0 mcg/kg/min (mean ± SD: 1.4 ± 1.1 mcg/kg/min). Clevidipine was paused a total of 43 times in the 30 cases. In 18 of the 30 patients (60%), the clevidipine infusion was temporarily paused more than once due to a MAP < 55 mmHg. A fluid bolus was administered to only 1 patient to treat the low MAP. No patient required the administration of a vasoactive agent for hypotension. When the clevidipine infusion was discontinued as controlled hypotension was no longer required, the MAP returned to baseline or ≥ 65 mmHg within 10 minutes in 12 of the 30 patients (40%). Clevidipine can be used to provide controlled hypotension during posterior spinal fusion. The response of the MAP, both the onset and duration of action, were rapid. Although titration of the infusion with occasional pauses of administration may be needed, excessive hypotension was not noted.

Decreasing the Need for Transfusion: Infant Cardiac Surgery Using Hemodilution and Recombinant Factor VIIa

Many strategies, including intraoperative acute normovolemic hemodilution (ANH) and pharmacologic agents, exist to minimize the use of allogeneic blood products in pediatric congenital heart surgery. Recombinant activated factor VIIa (rFVIIa) is a hemostatic agent approved for the treatment of bleeding episodes and prevention of bleeding in surgical interventions in patients with hemophilia A or B with inhibitors, acquired hemophilia, or congenital factor VII deficiency. Off-label use in nonhemophilic patients for uncontrolled hemorrhage is increasing although still under investigation. We present our experience with ANH and rFVIIa in nine patients. All were <16 months of age and underwent complex cardiac surgery with the end point of achieving hemostasis while decreasing or eliminating the need for allogeneic blood products. Clinically, we have observed rapid hemostasis in patients who underwent ANH and then had autologous blood reinfused after cardiopulmonary bypass, along with rFVIIa, without any time delay. The patients required no allogeneic blood products and therefore results suggested the potential utility of this practice. The study group consisted of nine patients <16 months of age who received rFVIIa in the operating room after open-heart surgery. Amount of autologous blood removed preoperatively, blood product use, time from protamine to rFVIIa administration, platelet count, INR, and fibrinogen level were retrospectively obtained. Of the nine patients, the three who underwent the most aggressive hemodilution received rFVIIa most rapidly and required no allogeneic blood products to achieve hemostasis although they had an average lower fibrinogen level on admission to the cardiothoracic intensive care unit. These preliminary data suggest that hemodilution before surgical stimulation and the rapid administration of rFVIIa, along with the reintroduction of autologous blood, may decrease or potentially eliminate the need for allogeneic blood products. Prospective trials are warranted to further explore this technique.

O-71 An international survey of transfusion practices in children undergoing cardiac surgery with cardiopulmonary bypass

Introduction. Patients undergoing surgery of the thoracic aorta during deep hypothermic cardiac arrest (DHCA) are at risk of increased postoperative bleeding. We report our strategy to achieve postoperative haemostasis guided by thromboelastometry in this surgical population. Method. This retrospective one-centre study included 103 patients from January 2009 until December 2010 who underwent elective surgery of the ascending aorta during DHCA. Coagulation management was guided by an algorithm based on thromboelastometric measurements (ROTEM®). We evaluated the amount of transfused haemostatic and blood products as well as the postoperative blood loss from mediastinal drainages and recorded all surgical revisions within 24 hours of surgery. Results. Sixty patients (58%) received haemostatic products, but no blood products including erythrocyte and platelet concentrates or fresh frozen plasma within 24 hours including surgery. Twenty-six patients, 25% of the total studied, received no haemostatic and no blood product. In the other 77 patients, median (range) transfusion volumes were 1 (0-8) units of erythrocyte concentrate, 0 (0-8) units of fresh frozen plasma, 0 (0-3) units of platelet concentrate, 2 (0-9) grams of fibrinogen concentrate (Haemocomplettan®), 0 (0-2400) units of prothrombin complex concentrate (Prothromblex®), and 0 (0-200) units of factor VIII concentrate (Haemate®). Mean ( SD) postoperative blood loss within the first 24 h was 540 ( 360) ml. One patient died intraoperatively due to heart failure. Three (3%) patients underwent surgical revision within 24 h, all due to surgical re-bleedings. Conclusions. The over-all moderate need for allogeneic blood products together with the avoidance of any blood products in more than 50% of our patients suggests that the goal-directed coagulation management guided by thromboelastometry might be advantageous in patients undergoing aortic surgery during DHCA. Our findings are in agreement with recent publications [1,2], but a missing control group precludes definite conclusions.

Efficiency and safety of preoperative autologous blood donation in cardiac surgery: a matched-pair analysis in 432 patients

A shortage of blood products is predicted for the near future in many countries all over the world. Preoperative autologous blood donation (PABD) in cardiac surgery is considered an option to reduce the need of allogeneic blood products. We analysed a 1-year period of our institutional database according to the safety and efficiency of our autologous blood donation programme. All patients who donated autologous blood prior to cardiac surgery were matched to a non-donor according to age, body weight, body mass index, sex, haemoglobin concentration, EuroSCORE, antifibrinolytic therapy and risk for bleeding. We analysed the occurrence of adverse effects during donation in all donors as well as the main perioperative data, haemoglobin levels and the need for allogeneic blood transfusion in all patients. There were no major cardiac events such as myocardial infarction, worsened cardiac insufficiency or death in the donor group during the PABD process. A total of 216 patients could be matched. Exposure to allogeneic blood products was significantly reduced in the donor group (packed red cells 70 patients (pts) vs 118 pts (p<0.001), fresh frozen plasma 26 pts vs 54 pts (p=0.001), platelets 10 pts vs 22 pts (p=ns)). There were no reports of transfusion-related side effects. Further, there was no difference in haemoglobin concentrations at postoperative day 1 and at discharge. In this large matched-pair analysis without the need for risk stratification, PABD reduces the need for allogeneic blood products in adult cardiac surgery. In a carefully selected cohort, PABD is a safe and efficient alternative to allogeneic transfusion.

Successful rotational thromboelastometry‐guided treatment of traumatic haemorrhage, hyperfibrinolysis and coagulopathy

Transfusion of allogeneic blood products is associated with increased morbidity and mortality. Therefore, strategies for reducing transfusion of these products during trauma management are valuable. We report a case of severe blunt abdominal trauma, successfully treated with antifibrinolytic medication and fibrinogen concentrate. Rotational thromboelastometry (ROTEM) was used to identify hyperfibrinolysis and afibrinogenaemia. In order to achieve haemostasis, over a 3-h period, the patient received a total of 1 g of tranexamic acid, 7 U of packed red blood cells, 16 g of fibrinogen concentrate (Haemocomplettan P), 3500 ml of colloids and 5500 ml of lactated Ringer's solution. Together with surgical measures, this treatment stopped the bleeding and stabilised the patient. There was no transfusion of either fresh-frozen plasma or platelets. The limited need for allogeneic blood products is of particular interest, and clinical studies of the approach used here appear to be warranted.

Tranexamic Acid Reduces Blood Loss in Off-Pump Coronary Artery Bypass Surgery

This study was designed to evaluate the hemostatic effect of tranexamic acid in off-pump coronary artery bypass surgery. A prospective, randomized, double-blind, placebo-controlled study. The Department of Anesthesiology and Cardiac Surgery, Medical Sciences University. One hundred eight patients undergoing off-pump coronary artery bypass surgery were enrolled into the study. Eight patients were withdrawn, and 100 patients were divided into 2 groups. Fifty patients received tranexamic acid (bolus 1 g before skin incision and followed by maintenance dose of 400 mg/h during surgery), and 50 patients received saline. Hematologic parameters, volume of blood loss, blood transfusion, and other clinical data were recorded throughout the perioperative period. Twenty-four-hour postoperative blood loss was significantly less in the tranexamic acid group compared with the control group (471 +/- 182 v 844 +/- 303). Patients in the tranexamic acid group received significantly less allogeneic blood (8 v 31 units). Bleeding and hemorrhagic complications and the consequent need for allogeneic transfusion are still major problems after off-pump coronary artery bypass surgery. Tranexamic acid appears to be effective in reducing postoperative bleeding and the need for allogeneic blood products.

Does Tranexamic Acid Reduce Blood Loss in Off-Pump Coronary Artery Bypass?

The hemostatic effect of tranexamic acid on the bleeding tendency and transfusion requirements in patients undergoing off-pump coronary artery bypass surgery was assessed in a prospective randomized double-blind study. Of 66 patients undergoing elective operations, 33 were given tranexamic acid (15 mg x kg(-1) before infusion of heparin and 15 mg x kg(-1) after protamine infusion), and the other 33 received only saline. Postoperative bleeding, transfusions, complications, hematological variables, and plasma D-dimer levels were recorded. Postoperative blood loss was significantly less in the tranexamic acid group compared to the control group (320 +/- 38 vs 480 +/- 75 mL). Patients in the tranexamic acid group received significantly less allogeneic blood products (0.46 vs 0.94 units per patient), and they had lower postoperative D-dimer levels. No postoperative thrombotic complications were observed in either group. Although off-pump coronary artery bypass surgery is associated with reduced frequency of hemorrhagic disorders, defective hemostasis still occurs, and tranexamic acid effectively reduces postoperative blood loss and the need for allogeneic blood products.

Aprotinin is useful as a hemostatic agent in cardiopulmonary surgery: yes.

Aprotinin is useful as a hemostatic agent in cardiopulmonary surgery: yes.

Platelet gel and fibrin sealant reduce allogeneic blood transfusions in total knee arthroplasty

Total knee arthroplasty (TKA) is often associated with a considerable amount of post-operative blood loss, necessitating the transfusion of allogeneic blood, which can add to the complications. Optimization of strategies to reduce the need for blood transfusion is desired. This study was designed to evaluate the efficacy of autologous platelet gel and fibrin sealant in unilateral TKA. Consecutive patients were operated on and assigned to the study and control groups. Study group patients (n = 85) were operated on according to our standard TKA protocol, with the application of autologous platelet gel and fibrin sealant on the wound tissues at the end of surgery. Eighty patients were operated on according to the same protocol, but without the use of platelet gel and fibrin sealant, and served as the control group. All blood transfusions, occurrence of wound leakage, wound healing disturbances and incidences of post-operative infections were recorded. Patients in the treatment group had a significantly higher post-operative haemoglobin level (11.3 vs. 8.9 g/dl, respectively) and a decreased need for allogeneic blood products (0.17 vs. 0.52 units, respectively) than those in the control group (P < 0.001). The incidences of wound leakage and wound healing disturbance were significantly less (P < 0.001) in patients managed with platelet gel and fibrin sealant. Four patients in the control group, who received blood products, developed wound infection. The hospital stay was decreased by 1.4 +/- 1.5 days for patients in the treatment group (P < 0.001). Peri-operatively applied platelet gel and fibrin sealant may reduce the incidence of allogeneic blood transfusions and complications associated with TKA.

3. Internationales Symposium: „Autologe Transfusion - Von der Euphorie zur Ratio: Praktisches Handeln aus wissenschaftlicher Sicht” (Teil II)Autologe Transfusion bei Kindern - Fremdblutsparende Verfahren

It is uncontested that blood-saving strategies should also be applied in children. However, in the past, blood-saving techniques saw limited use in children, although they are well-established in adults. This is due to technical and methodical problems, but also to the physiologically limited compensatory mechanisms for diminished oxygen delivery in this age group. For this reason, the various blood saving-techniques cannot be universally applied to all age groups. During the first year of life most perioperative techniques are of only limited benefit: even only a small amount of blood loss in relation to total blood volume makes a transfusion of allogeneic blood necessary, which is far before enough shed blood can be recovered for retransfusion. Preoperative autologous donation of blood calls for a high degree of cooperation by the child and the parents an is equally demanding in terms of organization and skills. Therefore, this procedure is used mainly in school-age children and in adolescents. Intraoperative blood salvage, by contrast, is already worthwhile in children from age one year with an expected blood loss of 20 % of blood volume. Acute normovolemic hemodilution and deliberate hypotension should be recommended only in an age group where cardiovascular compensatory mechanisms are given. Supporting procedures aimed at avoiding the need for allogeneic blood include perioperative administration of erythropoietin, iron supplementation, blood-saving surgical techniques and careful hemostasis. These prerequisites, the combination of various techniques, as well as the definition of an age-specific low transfusion trigger have contributed to a marked decrease in the need for allogeneic blood products in children in recent years.

Applications of Aprotinin in Cardiac Surgery

SUMMARYAprotinin has been studied extensively in cardiac surgery and is the only FDA approved pharmacological treatment to reduce blood transfusion in coronary artery bypass grafting (CABG) associated with cardiopulmonary bypass (CPB). Aprotinin has been evaluated in multiple double blind, placebo‐controlled, multicenter studies in cardiac surgery. In US studies, aprotinin has not been associated with an increased risk of post‐CPB myocardial infarction, graft closure, or increased risk of renal dysfunction, and may in fact be associated with a decreased risk of stroke. The mechanism of action is complex, but aprotinin displays antiinflammatory properties due to its complex array of protease inhibition. As with any polypeptide, there is a risk of anaphylaxis that is influenced by prior exposure. Cardiac surgery can be associated with significant bleeding and the need for allogeneic blood products. Although multiple approaches have been reported to reduce bleeding and transfusions, aprotinin represents an important pharmacologic strategy to reduce bleeding.

Quality of intraoperative autologous blood withdrawal used for retransfusion after cardiopulmonary bypass

Background Intraoperative autologous blood withdrawal protects the pooled blood from the deleterious effects of cardiopulmonary bypass. Following reinfusion after cardiopulmonary bypass, the fresh autologous blood contributes to less coagulation abnormalities and reduces postoperative bleeding and the need for allogeneic blood products. However, few data have been available concerning the quality and potential activation of fresh blood stored at room temperature in the operating room. Methods Forty coronary artery bypass grafting patients undergoing a consistent intraoperative and postoperative autotransfusion protocol had a median of 1,000 mL of autologous blood withdrawn before cardiopulmonary bypass. After heparinization the blood was drained from the venous catheter via venous cannula into standard blood bags and stored in the operating room until termination of cardiopulmonary bypass. Samples for hemostatic and inflammatory markers were taken from the pooled blood immediately before it was returned to the patient. Results There was some activation of platelets in the stored autologous blood, as measured by an increase of β-thromboglobulin. Indications of thrombin formation, as assessed by plasma levels of thrombin-antithrombin complex and prothrombin fragment 1.2 were not seen, and there was no fibrinolytic activity. The red blood cells remained intact, indicated by the absence of plasma free hemoglobin. As for the inflammatory response, the levels of the terminal complement complex remained stable, and the cytokines tumor necrosis factor-α and interleukin 6 levels were not increased during storage. The complement activation products increased minimally, but remained within normal ranges. Conclusions Except for slight activation of platelets, there was no indication of coagulation, hemolysis, fibrinolysis, or immunologic activity in the autologous blood after approximately 1 hour of operating room storage. The autologous blood was preserved in a condition of high quality, and retransfusion after cardiopulmonary bypass represents an uncomplicated and almost costless procedure for blood conservation.

Tranexamic acid in off-pump coronary surgery: a preliminary, randomized, double-blind, placebo-controlled study

Background. We evaluated the hemostatic effects of tranexamic acid, a synthetic antifibrinolytic drug, in patients undergoing beating-heart coronary surgery. Methods. Forty consecutive patients were in a double-blind manner, prospectively randomized into two groups: 20 patients received tranexamic acid (bolus of 1 g before skin incision, followed by continuous infusion of 400 mg/hr during surgery), and 20 patients received saline. As primary outcomes, bleeding and allogeneic transfusions were considered. D-dimer and fibrinogen plasma levels were also evaluated to monitor the activation of fibrinolysis. Major postoperative thrombotic events, as a potential consequence of antifibrinolytic treatment, were recorded. Results. The treatment group had significantly lower postoperative bleeding (median [25th to 75th percentiles]: 400 mL [337 to 490 mL] vs 650 ml [550 to 862 mL], p < 0.0001), lower need for allogeneic blood products (1,200 vs 5,300 mL, p < 0.001), and lower postoperative D-dimer plasma levels. No postoperative thrombotic complications were observed in either group. Conclusions. In this initial series of patients undergoing off-pump coronary surgery, tranexamic acid appears to be effective in reducing postoperative bleeding and the need for allogeneic blood products.

Reduction in Requirements for Allogeneic Blood Products: Nonpharmacologic Methods

Background. Various strategies have been proposed to decrease bleeding and allogeneic transfusion requirements during and after cardiac operations. This article attempts to document the usefulness, or lack thereof, of the nonpharmacologic methods available in clinical practice. Methods. Blood conservation methods were reviewed in chronologic order, as they become available to patients during the perisurgical period. The literature in support of or against each strategy was reexamined critically. Results. Avoidance of preoperative anemia and adherence to published guidelines for the practice of transfusion are of paramount importance. Intraoperatively, tolerance of low hemoglobin concentrations and use of autologous blood (predonated or harvested before bypass) will reduce allogeneic transfusions. The usefulness of plateletpheresis and retransfusion of shed mediastinal fluid remains controversial. Intraoperatively and postoperatively, maintenance of normothermia contributes to improved hemostasis. Conclusions. Several approaches have been shown to be effective. An efficient combination of methods can reduce, and sometimes abolish, the need for allogeneic blood products after cardiac operations, inasmuch as all those involved in the care of cardiac surgical patients adhere thoughtfully to existing transfusion guidelines.