Efficacy of a Simple Intraoperative Transfusion Algorithm for Nonerythrocyte Component Utilization after Cardiopulmonary Bypass

Background: Abnormal bleeding after cardiopulmonary bypass (CPB) is a common complication of cardiac surgery, with important health and economic consequences. Coagulation test-based algorithms may reduce transfusion of non-erythrocyte allogeneic blood in patients with abnormal bleeding.

Methods: The authors performed a randomized prospective trial comparing allogeneic transfusion practices in 92 adult patients with abnormal bleeding after CPB. Patients with abnormal bleeding were randomized to one of two groups: a control group following individual anesthesiologist's transfusion practices and a protocol group using a transfusion algorithm guided by coagulation tests.

Results: Among 836 eligible patients having all types of elective cardiac surgery requiring CPB, 92 patients developed abnormal bleeding after CPB (incidence, 11%). The transfusion algorithm group received less allogeneic fresh frozen plasma in the operating room after CPB (median, 0 units; range, 0-7 units) than the control group (median, 3 units; range, 0-10 units) (P = 0.0002). The median number of platelet units transfused in the operating room after CPB was 4 (range, 0-12) in the algorithm group compared with 6 (range, 0-18) in the control group (P = 0.0001). Intensive care unit (ICU) mediastinal blood loss was significantly less in the algorithm group. Multivariate analysis demonstrated that transfusion algorithm use resulted in reduced ICU blood loss. The control group also had a significantly greater incidence of surgical reoperation of the mediastinum for bleeding (11.8%vs. 0%;P = 0.032).     

Platelet-rich plasma sequestration, with therapeutic platelet yields, reduces allogeneic transfusion in complex cardiac surgery

Platelet dysfunction is the most common cause of nonsurgical bleeding after cardiopulmonary bypass (CPB). We hypothesized that reinfusion of a therapeutic quantity of platelets sequestered before CPB would decrease the need for allogeneic platelet transfusion, as well as decrease bleeding and total allogeneic transfusion, in cardiac surgery patients at moderately high risk for bleeding. Fifty-five patients undergoing either reoperative coronary artery bypass (CABG) or combined CABG and valve replacement were randomized to control or platelet-rich plasma sequestration (pheresis) groups. All patients received intraoperative epsilon-aminocaproic acid infusions. There was no significant difference between groups with respect to preoperative characteristics, duration of CPB, or target postoperative hematocrit. Mean platelet yields were 6.2 +/- 2.1 units (3.1 x 10(11) platelets). Mean pheresis time was 44 min. Allogeneic platelets (range = 6-12 units) were transfused to 28% of control patients, compared with 0% of pheresis patients (P < 0.01). Allogeneic packed red blood cells were transfused to 45% of control patients (1.2 units per patient) versus 31% of pheresis patients (0. 7 unit per patient) (P = 0.35). Total allogeneic units transfused were significantly reduced in the pheresis group (P < 0.02). Mediastinal chest tube drainage was not significantly decreased in the pheresis group. In this prospective, randomized study, therapeutic platelet yields were obtained before CPB. In contrast with recent studies with low platelet yields, these data support the conclusion that platelet-rich plasma sequestration is effective in reducing allogeneic platelet transfusions and total allogeneic units transfused in cardiac surgery patients at moderately high risk for post-CPB coagulopathy and bleeding. IMPLICATIONS: Transfusion of allogeneic blood products, including platelets, is common during complex cardiac surgical procedures. In the present prospective, randomized study, a significant reduction in allogeneic platelet transfusion and total allogeneic units transfused was observed after the reinfusion of a therapeutic quantity of autologous platelets sequestered before cardiopulmonary bypass.     

Thromboelastography-Based Transfusion Algorithm Reduces Blood Product Use after Elective CABG: A Prospective Randomized Study

Abstract   Objective: Bleeding and allogeneic transfusion remain constant problems in cardiac surgical procedures. In this study, we aimed to test the role of a routine thromboelastography (TEG)-based algorithm on bleeding and transfusions in patients undergoing elective coronary artery bypass grafting (CABG). Methods: Patients (n = 224) undergoing elective CABG with cardiopulmonary bypass were prospectively randomized into two groups according to transfusion strategy: in group 1 (clinician-directed transfusion, n = 110) need for blood transfusion was based on clinician's discretion and standard coagulation tests and in group 2 (TEG algorithm group, n = 114) kaolin-activated (k) TEG-based algorithm-guided perioperative transfusion management. Transfusion, blood loss, and outcome data were recorded.  Results: There were no differences in consumption of packed cell units, blood loss, re-exploration for bleeding, and early clinical outcome between the groups. Patients in the TEG group had significantly lower median units of fresh frozen plasma and platelets compared with the other group (p = 0.001). The median number of total allogeneic units transfused (packed cells and blood products) was significantly reduced in the TEG group compared with the other group (median 2, range 1–3 units vs. median 3, range 2–4 units, respectively, p = 0.001). The need for tranexamic acid was significantly diminished in the TEG group compared with the other group (10.3% vs. 19%, respectively, p = 0.007). Conclusion: Our results show that routine use of a kTEG-guided algorithm reduces the consumption of blood products in patients undergoing elective CABG. Adopting such an algorithm into routine management of these patients may help to improve clinical outcome and reduce the potential risks of transfusion-related complications and total costs after CABG.     

Randomized, Placebo-Controlled, Double-Blind Study of an Ultra-Low-Dose Aprotinin Regimen in Reoperative and/or Complex Cardiac Operations

A bstract Background and aim of the study : High-dose aprotinin is an effective but costly method to reduce transfusions after cardiopulmonary bypass (CPB). Very low doses of aprotinin have been shown to be effective in primary cardiac surgery, but not in patients undergoing procedures associated with the greatest usage of allogeneic blood products after CPB. We evaluated the efficacy of ultra-low-dose aprotinin in this patient population. Methods : Aprotinin 1 million KIU or placebo was added to the priming solution of the CPB circuit of 52 patients undergoing a reoperation and/or a complex surgical procedure. Dryness of operative field, hemoglobin concentrations, coagulation parameters, chest drainage, and transfusion requirements were compared. Results : Total chest drainage was not different between groups, but fewer patients in the aprotinin group required additional protamine postoperatively (35% vs 69% for controls, p = 0.03) and fewer received fresh frozen plasma (FFP; 19% vs 46% for controls, p = 0.04). Red cell transfusion was smaller in the aprotinin group compared to placebo (median 4 and 2 units, respectively, p = 0.04). Transfusion of FFP, platelets, cryoprecipitates was not different between groups. Total number of units transfused tended to be reduced in the aprotinin group compared to control (median 2 and 7 units, respectively, p = 0.06). Conclusions : Prophylactic administration of ultra-low-dose aprotinin reduced transfusions in patients undergoing repeat operations or complex procedures. Aprotinin could be used in a more economical manner, even in this patient population at high-risk of receiving allogeneic blood products.     

Coagulation tests during cardiopulmonary bypass correlate with blood loss in children undergoing cardiac surgery.

OBJECTIVES: To examine whether coagulation tests, sampled before and during cardiopulmonary bypass (CPB), are related to blood loss and blood product transfusion requirements, and to determine what test value(s) provide the best sensitivity and specificity for prediction of excessive hemorrhage. DESIGN: Prospective. SETTING: University-affiliated, pediatric medical center. PARTICIPANTS: Four hundred ninety-four children. INTERVENTIONS: Coagulation tests. MEASUREMENTS AND MAIN RESULTS: Demographic, coagulation test, blood loss, and transfusion data were noted in consecutive children undergoing cardiac surgery. Laboratory tests included hematocrit (Hct), prothrombin time, partial thromboplastin time (PTT), platelet count, fibrinogen concentration, and thromboelastography. Stepwise linear regression analysis indicated that platelet count during CPB was the variable most significantly associated with intraoperative blood loss (in milliliters per kilogram) and 12-hour chest tube output (in milliliters per kilogram). Other independent variables associated with blood loss were thromboelastography maximum amplitude (MA) during CPB, preoperative PTT, preoperative Hct, and preoperative thromboelastography angle and shear modulus values. Thromboelastography MA during CPB was the only variable associated with total products transfused (in milliliters per kilogram). Of all tests studied, platelet count during CPB (< or = 108,000/microL) provided the maximum sensitivity (83%) and specificity (58%) for prediction of excessive blood loss (receiver operating characteristic analysis). Blood loss was inversely related to patient age; neonates received the most donor units (median, 8 units; range, 6 to 10 units). CONCLUSIONS: During cardiac surgery, coagulation tests (including thromboelastography) drawn pre-CPB and during CPB are useful to identify children at risk for excessive bleeding. Platelet count during CPB was the variable most significantly associated with blood loss.     

Large volume acute normovolemic hemodilution in patients undergoing cardiac surgery with intermediate-high risk of transfusion: A randomized controlled trial

Study Objective: To investigate whether large volume acute normovolemic hemodilution (L-ANH), compared with moderate acute normovolemic hemodilution (M-ANH), can reduce perioperative allogeneic blood transfusion in patients with intermediate-high risk of transfusion during cardiac surgery with cardiopulmonary bypass (CPB).Design: Prospective randomized controlled trial.Setting: University hospital.Patients: Patients with transfusion risk understanding scoring tool (“TRUST”) ≥2 points undergoing cardiac surgery with CPB in the Second Affiliated Hospital of Zhejiang University from May 2020 to January 2021 were included.Interventions: The patients were randomly assigned with a 1:1 ratio to M-ANH (5 to 8 mL/kg) or L-ANH (12 to 15 mL/kg).Measurements: The primary outcome was perioperative red blood cell (RBC) transfusion units. The composite outcome included new-onset atrial fibrillation, pulmonary infection, cardiac surgery associated acute kidney injury (CSA-AKI) class ≥2, surgical incision infection, postoperative excessive bleeding, and resternotomy. Main results: Total 159 patients were screened and 110 (55 L-ANH and 55 M-ANH) were included for final analysis. Removed blood volume of L-ANH is significantly higher than M-ANH (886 ± 152 vs. 395 ± 86 mL, P < 0.001). Perioperative RBC transfusion was median 0 unit ([25th, 75th] percentiles: 0–4.4) in M-ANH group vs. 0 unit ([25th, 75th] percentiles: 0–2.0) in L-ANH group (P = 0.012) and L-ANH was associated with lower incidence of transfusion (23.6% vs. 41.8%, P = 0.042, rate difference: 0.182, 95% confidence interval [0.007–0.343]). The incidence of postoperative excessive bleeding was significantly lower in L-ANH vs. M-ANH (3.6% vs. 18.2%, P = 0.029, rate difference: 0.146, 95% confidence interval [0.027–0.270]) without significant difference for other second outcomes. The volume of ANH was inversely related to perioperative RBC transfusion units (Spearman r = −0.483, 95% confidence interval [−0.708 to −0.168], P = 0.003), and L-ANH in cardiac surgery was associated with a significantly reduced risk of perioperative RBC transfusion (odds ratio: 0.43, 95% confidence interval: 0.19–0.98, P = 0.044).Conclusions: Compared with M-ANH, L-ANH during cardiac surgery inclined to be associated with reduced perioperative RBC transfusion and the volume of RBC transfusion was inversely proportional to the volume of ANH. In addition, LANH during cardiac surgery was associated with a lower incidence of postoperative excessive bleeding.     

Comparison of Blood-conservation Strategies in Cardiac Surgery Patients at High Risk for Bleeding

Background: Aprotinin and tranexamic acid are routinely used to reduce bleeding in cardiac surgery. There is a large difference in agent price and perhaps in efficacy.

Methods: In a prospective, randomized, partially blinded study, 168 cardiac surgery patients at high risk for bleeding received either a full-dose aprotinin infusion, tranexamic acid (10-mg/kg load, 1-mg [middle dot] kg-1 [middle dot] h-1 infusion), tranexamic acid with pre-cardiopulmonary bypass autologous whole-blood collection (12.5% blood volume) and reinfusion after cardiopulmonary bypass (combined therapy), or saline infusion (placebo group).

Results: There were complete data in 160 patients. The aprotinin (n = 40) and combined therapy (n = 32) groups (data are median [range]) had similar reductions in blood loss in the first 4 h in the intensive care unit (225 [40-761] and 163 [25-760] ml, respectively;P = 0.014), erythrocyte transfusion requirements in the first 24 h in the intensive care unit (0 [0-3] and 0 [0-3] U, respectively;P = 0.004), and durations of time from end of cardiopulmonary bypass to discharge from the operating room (92 [57-215] and 94 [37, 186] min, respectively;P = 0.01) compared with the placebo group (n = 43). Ten patients in the combined therapy group (30.3%) required transfusion of the autologous blood during cardiopulmonary bypass for anemia.     

Comparison of blood-conservation strategies in cardiac surgery patients at high risk for bleeding

BACKGROUND: Aprotinin and tranexamic acid are routinely used to reduce bleeding in cardiac surgery. There is a large difference in agent price and perhaps in efficacy. METHODS: In a prospective, randomized, partially blinded study, 168 cardiac surgery patients at high risk for bleeding received either a full-dose aprotinin infusion, tranexamic acid (10-mg/kg load, 1-mg x kg(-1) x h(-1) infusion), tranexamic acid with pre-cardiopulmonary bypass autologous whole-blood collection (12.5% blood volume) and reinfusion after cardiopulmonary bypass (combined therapy), or saline infusion (placebo group). RESULTS: There were complete data in 160 patients. The aprotinin (n = 40) and combined therapy (n = 32) groups (data are median [range]) had similar reductions in blood loss in the first 4 h in the intensive care unit (225 [40-761] and 163 [25-760] ml, respectively; P = 0.014), erythrocyte transfusion requirements in the first 24 h in the intensive care unit (0 [0-3] and 0 [0-3] U, respectively; P = 0.004), and durations of time from end of cardiopulmonary bypass to discharge from the operating room (92 [57-215] and 94 [37, 186] min, respectively; P = 0.01) compared with the placebo group (n = 43). Ten patients in the combined therapy group (30.3%) required transfusion of the autologous blood during cardiopulmonary bypass for anemia. CONCLUSIONS: The combination therapy of tranexamic acid and intraoperative autologous blood collection provided similar reduction in blood loss and transfusion requirements as aprotinin. Cost analyses revealed that combined therapy and tranexamic acid therapy were the least costly therapies.     

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.     

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.     

Failure of autologous fresh frozen plasma to reduce blood loss and transfusion requirements in coronary artery bypass surgery

BACKGROUND: Previous studies failed to demonstrate any benefit from prophylaxis with fresh frozen plasma (FFP) after cardiopulmonary bypass (CPB). The results, however, were limited by either retrospective study design or use of FFP in subtherapeutic doses (2-3 units). The authors evaluated whether a therapeutic dose (15 ml/kg) of FFP reduces blood loss and transfusion requirements in elective coronary artery bypass surgery. The risks of multiple allogeneic blood donor exposure were circumvented by using autologous plasma. METHODS: Sixty adult patients scheduled for elective primary coronary artery bypass grafting were randomized to receive, after CPB, an intravenous infusion of 15 ml/kg of either autologous FFP (30 patients) or 6% hydroxyethyl starch 450/0.7 (HES; 30 patients). Autologous plasma was obtained by platelet-poor plasmapheresis several weeks before surgery. Perioperative blood transfusions were administered per protocol. Postoperative blood loss was defined as the chest tube drainage during the first 24 h after surgery. RESULTS: The data from 56 patients (FFP group, 27 patients; HES group, 29 patients) who completed the study according to protocol were analyzed. Median postoperative blood loss was 630 ml (range, 450-1,840 ml) and 830 ml (range, 340-1,980 ml) in the FFP and HES groups, respectively (P = 0.08). Both postoperative (0-24 h) and total perioperative erythrocyte transfusion requirements did not differ significantly between the groups (P = 0.32 and 0.14, respectively). CONCLUSION: The prophylactic administration of a therapeutic dose (15 ml/kg) of autologous FFP after CPB failed to reduce blood loss and transfusion requirements in patients undergoing uncomplicated, elective, primary coronary artery bypass surgery.     

Activated recombinant factor VII after cardiopulmonary bypass reduces allogeneic transfusion in complex non-coronary cardiac surgery: randomized double-blind placebo-controlled pilot study

Background. Receiving an allogeneic transfusion may be an independentpredictor of mortality for patients undergoing cardiac surgery.Furthermore, these patients utilize 15% of all donated bloodin the UK. In our unit, 80% of patients undergoing complex non-coronarycardiac surgery requiring cardiopulmonary bypass (CPB) receivean allogeneic transfusion. Activated recombinant FVII (rFVIIa)may be effective in reducing this need for transfusion. Methods. Twenty patients undergoing complex cardiac surgerywere randomized to receive rFVIIa or placebo after CPB and reversalof heparin. Results. Two patients in the rFVIIa group received 13 unitsof allogeneic red cells and coagulation products compared witheight patients receiving 105 units of allogeneic red cells andcoagulation products in the placebo group (relative risk ofany transfusion 0.26; confidence interval 0.07–0.9; P=0.037).The groups did not differ for adverse events. Conclusion. Despite major limitations (underpowered study andprone to type I error), we have shown that rFVIIa significantlyreduces the need for allogeneic transfusion in complex non-coronarycardiac surgery without causing adverse events.      

Coagulation tests predict bleeding after cardiopulmonary bypass

To determine the accuracy of coagulation profile laboratory tests, thromboelastography, and Sonoclot (SCT) values for predicting microvascular bleeding after cardiopulmonary bypass (CPB). A prospective, blinded trial. A large academic medical center. Eighty-two adult patients undergoing elective cardiac surgery. Ten minutes after CPB, thromboelastography, SCT, and coagulation profile tests (bleeding time, prothrombin time, activated partial thromboplastin time, fibrinogen, fibrin split products, platelet count, mean platelet volume, and platelet hematocrit) were determined from a whole blood sample taken from an existing arterial catheter. Patients were subjectively defined as “bleeders” or “non-bleeders” by blinded clinical observers. Preoperative baseline tests were also obtained.

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Thirty of the 82 patients (36.6%) were characterized as bleeders. Coagulation profile tests had the best correlation with intraoperative and postoperative blood loss. The specificity, sensitivity, and negative and positive predictive values were determined by receiver operating characteristic analysis, and the test values that differentiated normal from abnormal (bleeding) patients were determined. The coagulation profile laboratory tests had the greatest maximal sensitivity and specificity for predicting bleeding. These predictive values were outside the normal range for these laboratory tests. The thromboelastography values that produced maximal sensitivity and specificity were in the normal range for that test. Contrary to previous studies, coagulation profile tests had the greatest sensitivity and specificity to differentiate patients with excessive bleeding (abnormal) from those without excessive bleeding (normal) after CPB. Therefore, these tests should be used to guide transfusion therapy in patients who have excessive bleeding after CPB.     

Low-dose aprotinin is ineffective to treat excessive bleeding after cardiopulmonary bypass

BACKGROUND: Uncontrolled clinical experience at our institution suggested that low-dose aprotinin could control excessive bleeding after cardiopulmonary bypass (CPB). A randomized clinical trial was conducted to determine the efficacy of low-dose aprotinin in the treatment of hemorrhage after cardiac surgery. METHODS: One hundred seventy-one patients undergoing cardiac surgery with CPB were included. Forty-four patients (26%) bled significantly in the intensive care unit (>100 mL/h) and received either aprotinin (200,000 KIU bolus + 100,000 KIU/h for 8 hours) or placebo in addition to our standard management of excessive bleeding. RESULTS: Median bleeding before study drug administration was not different between aprotinin (200 mL) and placebo (212.5 mL) groups. Bleeding decreased significantly with time and similarly in both groups. Ninety-five percent of patients required transfusions in both groups. Median blood products transfused were 13 and 8 units per patient in the aprotinin and placebo groups respectively (p = NS). CONCLUSIONS: Routine administration of low-dose aprotinin as part of the treatment protocol to control hemorrhage after CPB does not reduce bleeding or transfusion requirements and, therefore, cannot be recommended.     

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.     

Absence of beneficial effect of acute normovolemic hemodilution combined with aprotinin on allogeneic blood transfusion requirements in cardiac surgery

BACKGROUND: The efficacy of acute normovolemic hemodilution (ANH) in decreasing allogeneic blood requirements remains controversial during cardiac surgery. METHODS: In a prospective, randomized study, 80 adult cardiac surgical patients with normal cardiac function and no high risk of ischemic complications were subjected either to ANH, from a mean hematocrit of 43% to 28%, or to a control group. Aprotinin and intraoperative blood cell salvage were used in both groups. Blood (autologous or allogeneic) was transfused when the hematocrit was less than 17% during cardiopulmonary bypass, less than 25% after cardiopulmonary bypass, or whenever clinically indicated. RESULTS: The amount of whole blood collected during ANH ranged from 10 to 40% of the patients' estimated blood volume. Intraoperative and postoperative blood losses were not different between control and ANH patients (total blood loss, control: 1,411 +/- 570 ml, n = 41; ANH: 1,326 +/- 509 ml, n = 36). Allogeneic blood was given in 29% of control patients (median, 2; range, 1-3 units of packed erythrocytes) and in 33% of ANH patients (median, 2; range, 1-5 units of packed erythrocytes; P = 0.219). Preoperative and postoperative platelet count, prothrombin time, and partial thromboplastin time were similar between groups. Perioperative morbidity and mortality were not different in both groups, and similar hematocrit values were observed at hospital discharge (33.7 +/- 3.9% in the control group and 32.6 +/- 3.7% in the ANH group; nonsignificant) CONCLUSIONS: Hemodilution is not an effective means to lower the risk of allogeneic blood transfusion in elective cardiac surgical patients with normal cardiac function and in the absence of high risk for coronary ischemia, provided standard intraoperative cell saving and high-dose aprotinin are used.     

Failure of Autologous Fresh Frozen Plasma to Reduce Blood Loss and Transfusion Requirements in Coronary Artery Bypass Surgery

Background: Previous studies failed to demonstrate any benefit from prophylaxis with fresh frozen plasma (FFP) after cardiopulmonary bypass (CPB). The results, however, were limited by either retrospective study design or use of FFP in subtherapeutic doses (2-3 units). The authors evaluated whether a therapeutic dose (15 ml/kg) of FFP reduces blood loss and transfusion requirements in elective coronary artery bypass surgery. The risks of multiple allogeneic blood donor exposure were circumvented by using autologous plasma.

Methods: Sixty adult patients scheduled for elective primary coronary artery bypass grafting were randomized to receive, after CPB, an intravenous infusion of 15 ml/kg of either autologous FFP (30 patients) or 6% hydroxyethyl starch 450/0.7 (HES; 30 patients). Autologous plasma was obtained by platelet-poor plasmapheresis several weeks before surgery. Perioperative blood transfusions were administered per protocol. Postoperative blood loss was defined as the chest tube drainage during the first 24 h after surgery.

Results: The data from 56 patients (FFP group, 27 patients; HES group, 29 patients) who completed the study according to protocol were analyzed. Median postoperative blood loss was 630 ml (range, 450-1,840 ml) and 830 ml (range, 340-1,980 ml) in the FFP and HES groups, respectively (P = 0.08). Both postoperative (0-24 h) and total perioperative erythrocyte transfusion requirements did not differ significantly between the groups (P = 0.32 and 0.14, respectively).     

Audit of factor VIIa for bleeding resistant to conventional therapy following complex cardiac surgery

PURPOSE: There are an increasing number of anecdotal reports and trials of recombinant activated factor VII (rFVIIa) for bleeding during surgery. The reports of rFVIIa during cardiac surgery are limited. We report our experience using rFVIIa, in the operating room; to treat bleeding that prevented chest closure, despite appropriate conventional treatment, following complex cardiac surgery. METHODS: Retrospective chart review, at an Australian University hospital and associated private hospital, of cardiac surgery patients given rFVIIa (usual dose 90 microg.kg(-1)). We used rFVIIa for bleeding that prevented closure of the chest despite administration of blood products, protamine, and surgical attempts to secure hemostasis. RESULTS: Recombinant activated factor VII was administered on 55 occasions to 53 patients. Most patients had complex aortic or valve surgery. Median bypass time was 266 min. Before administering rFVIIa, patients received (median): packed red cells four units; platelets 15 units; fresh frozen plasma eight units; and cryoprecipitate ten units. After administering rFVIIa the median doses of donor blood products up to 12 hr after intensive care unit admission were: packed red cells one unit; platelets zero units; fresh frozen plasma zero units; and cryoprecipitate zero units. The decrease in doses of all blood products was significant (P < 0.001). We could not determine if rFVIIa played a role in significant mortality (19%) and morbidity (17%). CONCLUSION: Use of rFVIIa in cardiac surgery may be effective, but definitive clinical trials are needed to clarify its role in clinical practice and safety. We present an rFVIIa guideline developed during the audit period.     

Randomized, multicentre, double-blind, placebo-controlled trial of the use of aprotinin in the repair of ruptured abdominal aortic aneurysm. On behalf of the Joint Vascular Research Group

BACKGROUND: The use of aprotinin in cardiac surgery reduces blood transfusion requirements. The aim of this trial was to see whether the same benefit applies in the repair of ruptured abdominal aortic aneurysm (AAA). METHODS: In this prospective, randomized trial, nine centres with local ethics committee approval recruited 77 patients with a ruptured AAA. A bolus of aprotinin 2 x 106 units, followed by an infusion of 0.5 x 106 units every 30 min, was administered to 38 patients, and 39 received a placebo infusion. The quantity of blood products transfused during surgery and in the first 12 h after operation was noted, along with the incidence of complications, mortality rates and length of hospital stay. RESULTS: Seventeen of the 38 patients who received aprotinin and 17 of the 39 given placebo died within 30 days (overall mortality rate 44 per cent). The median amount of blood given to the aprotinin group after operation was 1 (range 0-14) unit, while for the placebo group it was 3 (range 0-13) units (P = 0.02). However, the difference in the total number of units of blood transfused did not reach significance (10 (range 2-29) versus 14 (range 4-38) units respectively). CONCLUSION: The use of high-dose aprotinin during the repair of a ruptured AAA reduced blood transfusion requirements in the first 12 h after operation, but had no significant effect on the overall blood transfusion requirement.     

CO2部分重吸入法测心排血量在冠脉搭桥术中的应用

目的 观察CO2部分重吸入法测心排血量在冠脉搭桥术中的应用。方法 选择冠脉搭桥术26例,于诱导后、切皮、体外循环转流前、停转流后60min、停转流90min、术毕及术后监护室各时点采用CO2部分重吸入法测心排血量（RBco),并与温度稀释法（TDco)作比较。结果 于诱导后、切皮、停转流90min、术毕、术后监护室RBco和TDco测量数值均无显著性差异（P＞0．05）,于转流前、转流后60min测量值有显著性差异（P＜0．05）。各时点RBco和TDco相关系数均P＜0．01,其中术后监护室中的相关系数最高,r＝0．8511。结论 CO2部分重吸入法测心排血量在冠脉搭桥术术后监测中有良好的准确度,术中监测也有一定的临床价值。