Heparin-coated versus uncoated extracorporeal circuit in patients undergoing coronary artery bypass graft surgery

OBJECTIVE: To assess the effect of heparin-coated circuits on bleeding, transfusion, and platelet count in patients undergoing primary coronary artery bypass grafting with full heparinization. DESIGN: Randomized, double-blind study. SETTING: Tertiary-care academic medical center. PARTICIPANTS: Eighty-eight patients undergoing coronary artery bypass grafting requiring cardiopulmonary bypass (CPB) without previous sternotomy. INTERVENTIONS: Subjects received either a heparin-coated or an uncoated extracorporeal circuit for CPB. Heparin, 300 micro/kg, was administered, and supplemental amounts were administered to maintain an activated coagulation time of greater than 480 seconds. Platelet counts were determined during CPB. Mediastinal chest tube drainage was collected in the intensive care unit for 24 hours. MEASUREMENTS AND MAIN RESULTS: The mean platelet counts were similar between the groups during CPB. There was no significant difference in 24-hour mediastinal chest tube drainage (mean +/- standard deviation; median) between the heparin-coated (n = 44, 1096 +/- 401, 1015 mL) and uncoated group (n = 44, 1150 +/- 548, 1040 mL; p = 0.91). The heparin-coated group received less allogeneic packed red blood cells (0.9 +/- 1.6, 0.0 v 1.5 +/- 1.8, 1.0 U; p = 0.04). CONCLUSIONS: The use of a heparin-coated or uncoated cardiopulmonary bypass circuit and full heparinization marginally reduced only red blood cell transfusion but was not associated with platelet sparing or reduced perioperative bleeding.     

The treatment of heparin resistance with Antithrombin III in cardiac surgery

PURPOSE: To report three patients who developed heparin resistance during cardiac surgery which was successfully managed with 1000 U Antithrombin III (AT III). CLINICAL FEATURES: We observed heparin resistance prior to cardiopulmonary bypass (CPB) in one patient and during the CPB in two patients. In the first patient who was scheduled for mitral valve replacement, although heparin was administered sequentially up to 500 U x kg(-1) prior the CPB, the ACT value was 354 sec. After 1,000 U ATIII were administered the ACT was 395 sec and CPB was initiated. The ACT remained between 496 and 599 sec throughout CPB and a total of 260 mg protamine sulfate was given. In the other two patients following 300 U x kg(-1) heparin, the ACT was up to 400 sec and CPB was initiated. During CPB, ACT were decreased 360 sec and 295 sec in patients II and III respectively. Although heparin was added 1,500 U, ACT increased to > or = 400 sec could not be achieved. In the second patient ATIII activity was found 10%. After the administration of 1,000 U ATIII, ATIII activity was found to be 67% 40 min later and ACT were increased up to 400 sec. There was no thrombosis within the extracorporeal circuit, additional heparin was not required, less protamine was administered (< or = 3 mg x kg(-1)) and no excessive postoperative bleeding was observed in all patients. CONCLUSION: We recommend that AT III supplementation should be considered to manage heparin resistance prior or during CPB in patients undergoing open heart surgery.     

Preoperative autologous blood donation with cardiac surgery

BACKGROUND: Preoperative autologous blood donation is commonly used to reduce exposure to homologous blood transfusions among patients undergoing elective cardiac surgery. The purpose of this study was to ascertain how much volume of predonated autologous blood need to avoid of homologous blood transfusion in cardiac procedure. METHODS: One hundred twenty-eight patients underwent scheduled cardiac procedure between January 1998 and December 1999. Group 1: 400 ml predonated, operation without cardiopulmonary bypass (CPB) [n = 33], group 2: 800 ml predonated, operation without CPB (n = 23), group 3: 800 ml predonated, operation with CPB (n = 36), group 4: 1,200 ml predonated, operation with CPB (n = 36). Surgical procedures underwent only off-pump coronary artery bypass grafting (OPCAB) in groups 1 and 2. In groups 3 and 4 included coronary artery bypass grafting (CABG), valve replacement, CABG + valve replacement and atrial septal defect repair. RESULTS: There were no significant differences in mean body weight, mean preoperative hematocrit values or mean volume of intraoperative blood loss between groups 1 and 2. There were no significant differences in mean age, mean body weight, mean preoperative and postoperative day-7 hematocrit values, mean volume of intraoperative blood loss or mean CPB time between groups 3 and 4. The mean postoperative day-7 hematocrit value was significantly lower in group 1 than in group 2. Homologous blood transfusion was avoided in 63.6% of those with predonation of group 1 versus 100% at group 2 (p < 0.05), 86.1% at group 3 versus 94.4% at group 4 (p < 0.05). In group 3, all patients who underwent redo operation or CABG + valve replacement needed homologous blood transfusion. CONCLUSIONS: Autologous blood transfusion is effective for reducing the homologous blood requirement. It also seems that predonation of 800 ml may be sufficient to avoid homologous blood transfusion in cardiac surgery, however predonation of 1,200 ml is desirable in cases of redo operation or CABG + valve replacement.     

Effects of cell saver autologous blood transfusion on blood loss and homologous blood transfusion requirements in patients undergoing cardiac surgery on- versus off-cardiopulmonary bypass: a randomised trial.

OBJECTIVE: Off-pump CABG is potentially associated with reduced intraoperative blood loss and homologous blood transfusion in comparison to on-pump CABG. In this randomised controlled study we investigated the effects of autologous cell saver blood transfusion on blood loss and homologous blood transfusion requirements in patients undergoing CABG on- versus off-CPB. METHODS: Eighty patients were randomised into one of four groups: (A) on-CPB with cell saver blood transfusion (CSBT), (B) on-CPB without CSBT, (C) off-pump with CSBT and (D) off-pump without CSBT. Volume of intraoperative autologous blood transfusion, postoperative mediastinal blood loss and homologous blood transfusion requirements were measured. Homologous blood was transfused when haemoglobin concentration fell below 8 g/dl postoperatively. Pre- and postoperatively prothrombin time and partial thromboplastin time were measured. RESULTS: Preoperative patient characteristics were well matched among the four groups. The amount of salvaged mediastinal blood available for autologous transfusion was significantly higher in the on-pump group (A) compared to the off-CPB group (C) (433+/-155 ml vs 271+/-144 ml, P=0.001). Volume of homologous blood transfusion was significantly higher in group B vs groups A, C and D (595+/-438 ml vs 179+/-214, 141+/-183 and 230+/-240 ml, respectively, P<0.005). The cell saver groups (A and C) received significantly less homologous blood than the groups without cell saver (160+/-197 ml vs 413+/-394 ml, respectively, P<0.005). Patients undergoing off-CPB surgery received significantly less homologous blood than those undergoing on-CPB CABG irrespective of cell saver blood transfusion (184+/-214 ml vs 382+/-397 ml, P<0.05). Postoperative blood loss was similar in the four groups (842+/-276, 1023+/-291, 869+/-286 and 903+/-315 ml in groups A to D, respectively, P>0.05). Clotting test results revealed no significant difference between the groups. There was no significant difference in postoperative morbidity between groups. CONCLUSION: Off-pump CABG is associated with significant reduction in intraoperative mediastinal blood loss and homologous transfusion requirements. Autologous transfusion of salvaged washed mediastinal blood reduced homologous transfusion significantly in the on-CPB group. Cell saver caused no significant adverse impact on coagulation parameters in on- or off-CPB CABG. Postoperative morbidity and blood loss were not affected by the use of CPB or autologous blood transfusion. We recommend the use of autologous blood transfusion in both on- and off-pump CABG surgery.     

Preoperative autologous blood donation in elderly patients with cardiovascular surgery

BACKGROUND: During the cardiovascular surgeries in elderly people, only a few cases can avoid the homologous blood transfusion, because of their preoperative anemic tendency and low hemopoietic abilities. We examined the capability to avoid the homologous blood transfusion in over 75 year old patients by the preoperative autologous blood collection. Sixty-six patients underwent scheduled cardiovascular surgery between January 1996 and December 1999. The groups were divided into three categories of preoperatively collected autologous blood amounts: high-amount (800-1,200 ml), medium-amount (200-800 ml), and low-amount (0 ml). Each group was divided into two subgroups in according to the use of cardiopulmonary bypass (CPB). There were no differences among the each group in age, body weight, or preoperative and postoperative day-7 hematocrit values. RESULTS: Only 21.2% of patients could donate the expected blood amounts preoperatively. Mean volume was 641 ml. In groups used CPB, no patient was transfused homologous blood in high-amount group. On the contrary, 100% patients were donated in medium and low amount groups. In groups operated without CPB, homologous blood transfusion was required 14.3% in high-amount group, 25.0% in medium-amount group, and 83.3% in low-amount group. CONCLUSION: It seems that predonation of more than 800 ml may be sufficient to avoid the homologous blood transfusion in using CPB operation and more than 400 ml in non using CPB operation.     

Influence of high-dose aprotinin treatment on blood loss and coagulation patterns in patients undergoing myocardial revascularization.

Intraoperative administration of the proteinase inhibitor aprotinin causes reduction in blood loss and homologous blood requirement in patients undergoing cardiac surgery. To ascertain the blood-saving effect of aprotinin and to obtain further information about the mode of action, 40 patients undergoing primary myocardial revascularization were randomly assigned to receive either aprotinin or placebo treatment. Aprotinin was given as a bolus of 2 x 10(6) kallikrein inactivator units (KIU) before surgery followed by a continuous infusion of 5 x 10(5) KIU/h during surgery. Additionally, 2 x 10(6) KIU were added to the pump prime. Strict criteria were used to obtain a homogeneous patient selection. Total blood loss was reduced from 1,431 +/- 760 ml in the control group to 738 +/- 411 ml in the aprotinin group (P less than 0.05) and the homologous blood requirement from 838 +/- 963 ml to 163 +/- 308 ml (P less than 0.05). In the control group, 2.3 +/- 2.2 U of homologous blood or blood products were given, and in the aprotinin group, 0.63 +/- 0.96 U were given (P less than 0.05). Twenty-five percent of patients in the control group and 63% in the aprotinin group did not receive banked blood or homologous blood products. The activated clotting time as an indicator of inhibition of the contact phase of coagulation was significantly increased before heparinization in the aprotinin group (141 +/- 13 s vs. 122 +/- 25 s) and remained significantly increased until heparin was neutralized after cardiopulmonary bypass (CPB).(ABSTRACT TRUNCATED AT 250 WORDS)     

Safety and efficacy of autologous blood donation before elective off-pump coronary artery bypass grafting

BACKGROUND: Preoperative autologous blood donation reduces exposure to homologous blood transfusions in cardiac surgery. The purpose of this study was to ascertain, how much volume of predonated autologous blood needed to avoid of homologous blood transfusion in scheduled off-pump coronary artery bypass grafting (OPCAB). METHOD: Fifty patients underwent scheduled OPCAB. These patients donated 400 ml (group A, n = 30) or 800 ml (group B, n = 20) of autologous blood before operation. These patients donated at a rate of 400 ml per week. All patients were given an equal volume of saline solution at the time of autologous donation. RESULT: There were no significant differences mean age, mean body weight, mean preoperative hematocrit values, mean graft number or mean volume of intraoperative blood loss between groups A and B. There was significant difference the mean postoperative day-7 hematocrit value (33.4 +/- 1.5% vs 38.7 +/- 1.5%, p < 0.05). The rates of avoiding homologous blood transfusion were 63.3% in group A and 100% in group B (p < 0.05). CONCLUSIONS: Autologous blood transfusion was effective for reducing the homologous blood requirement. We believe that 800 ml predonation is sufficient to avoid homologous blood transfusion in scheduled OPCAB, further patients with cardiovascular disease including severe coronary artery should be donated with the administration of saline.     

Replacing cardiopulmonary bypass with extracorporeal membrane oxygenation in lung transplantation operations

Cardiopulmonary bypass (CPB) is required in some lung transplantation (LTx) operations. However, it increases risks of bleeding and early graft dysfunction. We report our experiences of replacing CPB with heparin-bound extracorporeal membrane oxygenation (ECMO) in LTx operations. If extracorporeal circulation was anticipated for the LTx operations, ECMO support was set up through the femoral venoarterial route after induction of anesthesia; then, LTx was done as usual. Five thousand units of heparin was injected intravenously during the femoral vessels cannulation, but no more was used during the first 24 h of ECMO support. If necessary, as in patients undergoing single LTx for end-stage pulmonary hypertension, the ECMO support was directly extended into the postoperative period until reperfusion edema of the graft lung subsided. Twelve single LTxs and 3 bilateral sequential single LTxs were done under ECMO support. The advantages of using femoral ECMO rather than conventional CPB in LTx operations were the operative field was not disturbed by the bypass cannula, stable cardiopulmonary function and normothermia were maintained throughout the operations, there were less blood loss and transfusion requirements, and the left LTx was as easily performed as the right LTx. Red blood cell transfusion requirements during the operation and the first postoperative day were 4.4 +/- 2.8 and 2.4 +/- 2.0 U, respectively, in 10 adult patients undergoing uncomplicated single LTx with ECMO support, and 4.3 +/- 1.3 and 1.5 +/- 1.5 U in 8 adult patients undergoing single LTx without any extracorporeal circulatory support. The difference was not significant between the 2 groups (p = 0.53 and 0.32 by Mann-Whitney U test). The ECMO did not increase blood transfusion requirements. In comparison, 13 U of red blood cell transfusion was required in 2 patients receiving single LTx under CPB support. The ECMO support made the postoperative critical care easier in recipients with graft lung edema. Except for 2 cases of primary graft failure, the ECMO could be weaned off and removed at bedside within a short period (27.9 +/- 24.6 h, n = 13) with no major complications. In conclusion, the heparin-bound femoral ECMO rather than CPB should be used for LTx operations unless concomitant cardiac repair is planned.     

Transfusion and bleeding in coronary artery bypass grafting: an on-pump versus off-pump comparison

Blood transfusion rates in coronary artery bypass grafting (CABG) surgery using cardiopulmonary bypass (CPB) are typically higher compared with off-pump CABG (OPCAB). However, few studies have specifically examined intraoperative hemodilution as a contributing factor. The aim of this retrospective review was to compare the effect of using CPB or OPCAB on red blood cell (RBC) transfusion and postoperative bleeding. The lowest intraoperative hematocrit (Hct) was used as marker of intraoperative hemodilution. We reviewed the perioperative data of all isolated CABG patients at a metropolitan hospital from January 2003 to June 2005. Stepwise regression analyses were performed to determine whether CPB was an independent predictor of RBC transfusion, reoperation for bleeding, or postoperative chest drainage. Of a total of 1043 patients, there were 433 CPB and 610 off-pump cases. CPB use was not significantly related to increased RBC transfusions (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.63-1.52; p = .921) and was associated with a lower incidence of reoperations for bleeding (OR, 0.4; 95% CI, 0.2-0.8; p = .009). There was less chest drainage over the first 12 hours in patients undergoing CPB (p < .0001); however, total postoperative chest drainage was not significantly related to operative procedure (p = .122). The lowest documented intraoperative Hct was a significant factor in RBC transfusions (OR, 0.89; p < .0001), an increased reoperation rate for bleeding (OR, 0.9; p = .001) and more postoperative chest drainage (log10-transformed: at 12 hours, b = -0.009, p < .0001; total, b = -0.006, p < .0001). CPB is not an independent risk factor in the incidence of RBC transfusions and is not associated with increased postoperative bleeding for isolated CABG. However, intraoperative hemodilution is an independent risk factor, with a lower intraoperative Hct associated with more RBC transfusions, increased reoperations for bleeding, and increased postoperative chest drainage. Addressing intraoperative hemodilution is important in minimizing CPB-associated morbidities.     

Heparin content of washed red blood cells from the cardiopulmonary bypass circuit.

Reinfusion of red blood cells (RBC) from the extracorporeal circuit following cardiopulmonary bypass (CPB) reduces patient exposure to homologous blood. Because infusing unneutralized heparin might exacerbate postoperative bleeding, this study examines the heparin content of the washed packed RBC produced by a commonly used autotransfusion device. This RBC product was derived from the residual whole blood in the oxygenator circuit after CPB. A wash volume of 750 mL of normal saline produced heparin concentrations below 0.04 USP U/mL. A 500 mL wash volume yielded heparin concentrations ranging from 0.08 to 0.22 USP U/mL, and could be used if time did not permit an additional wash. RBCs produced by the usual complete wash cycle do not contain clinically significant amounts of heparin; thus, they would not require a supplemental protamine dose.     

Preoperative use of enoxaparin is not a risk factor for postoperative bleeding after coronary artery bypass surgery

BACKGROUND: The purpose of this study was to determine whether the use of low-molecular-weight heparin before coronary artery bypass surgery would be associated with an increase in bleeding and use of blood products after the operation. METHODS: Sixty-four patients (48 men and 16 women) aged 64 +/- 10 years who were undergoing primary coronary artery bypass surgery were prospectively studied. Forty-one patients were treated with either subcutaneous enoxaparin 1 mg/kg twice daily (n = 21; enoxaparin group) or intravenous heparin (n = 20; heparin group). Patients received the last dose of enoxaparin 8.7 +/- 0.75 hours (range, 8-10 hours) before skin incision. Heparin was stopped before transfer to the operating room. An additional 23 consecutive patients who received neither enoxaparin nor heparin served as controls (n = 23). Anti-factor Xa activity, a measure of enoxaparin and heparin activity, was measured at the start of the operation in all patients. RESULTS: There was no perioperative mortality. The length of stay and frequency of postoperative complications were similar between groups. Preoperative anti-factor Xa activity was present only in the enoxaparin group (0.43 +/- 0.25 IU/mL). Chest tube drainage at 24 hours was 553 +/- 160 mL, 532 +/- 140 mL, and 587 +/- 230 mL for the enoxaparin, heparin, and control groups, respectively (P =.48). There was no difference among groups in the amount of blood products transfused. CONCLUSIONS: Enoxaparin administration more than 8 hours before coronary artery bypass surgery is not associated with increased postoperative bleeding or blood product transfusion.     

Efficacy of FK633, an ultra-short acting glycoprotein IIb/IIIa antagonist on platelet preservation during and after cardiopulmonary bypass.

OBJECTIVE: Temporary pharmacologic inhibition of platelet function during and after cardiopulmonary bypass (CPB) (platelet anesthesia) is an attractive strategy for preserving platelets during CPB. We examined the efficacy of FK633, an ultra-short acting glycoprotein IIb/IIIa antagonist. METHODS: The study was carried out in six mongrel dogs that received an intravenous bolus of 0.1 mg/kg of FK633 at the time of administration of heparin (group F), and six control dogs (group C). All animals underwent 60 min of normothermic CPB followed by a 2-h observation period. Blood samples for platelet count, platelet aggregation to adenosine diphosphate and parameters concerning the coagulation system were obtained at eight time points. Hemodynamics, bleeding time, and postoperative blood loss were assessed serially. Scanning electron micrograph of the oxygenator's membrane was investigated. RESULTS: FK633 significantly protected platelet number (group F, 59+/-10% versus group C, 38+/-15% of the pre-CPB value; P < 0.01), and inhibited platelet aggregation to adenosine diphosphate (group F, 13+/-12% versus group C, 35+/-9% of the pre-CPB value; P < 0.01) during CPB. Postoperative blood loss did not significantly differ between the two groups, but there was a tendency of less bleeding in group F (group F, 73+/-23 ml versus group C, 111+/-44 ml; P = 0.09). In group F, scanning electron micrograph of the oxygenator's membrane showed that its surface was free from platelets. There were no significant differences between the groups in hemodynamics. CONCLUSIONS: An ultra-short acting glycoprotein IIb/IIIa antagonist, FK633, is effective in preventing both platelet aggregation and thrombocytopenia during CPB, and may be effective for minimizing postoperative bleeding.     

Heparin-coated cardiopulmonary bypass circuits reduce blood cell trauma. Experiments in the pig

Blood cell trauma and postoperative bleeding remain important problems in cardiopulmonary bypass (CPB). We compared heparin-coated with non-coated circuits in the pig. Twenty animals were perfused for 2 h at normothermia using membrane oxygenators (Bentley Bos 50). Two groups were studied. In the non-coated group (NC, n = 11) the CPB circuits used were without a heparin coating. This group had systemic heparinization of 400 IU/kg to maintain an ACT (activated clotting time) of over 400 s during CPB. In the coated group (C, n = 9), all surfaces exposed to blood in the CPB circuits were heparin-coated. This group had the heparin dose reduced to 25% (100 IU/kg) without further administration regardless of ACT. During CPB, group C displayed shorter ACT (per definition), higher platelet count, platelet adhesion and lower fibrinolysis and haemolysis (P less than 0.05) as compared to group NC. No thromboembolic events were detected during CPB. Three animals in group NC and 4 animals in group C were weaned from CPB and protaminized. Four hours postoperatively, the leucocyte consumption was two-fold greater and blood loss about four-fold greater in group NC as compared with group C (P less than 0.05). Perfusion with heparin-coated surfaces reduces blood cell trauma. The decreased postoperative blood loss observed in group C is probably explained by the reduced dosages of heparin and protamine.     

Heparin-coated circuits (Duraflo II) with reduced versus full anticoagulation during coronary artery bypass surgery

BACKGROUND: Introduction of completely heparin-coated cardiopulmonary bypass (CPB) circuits combined with reduced systemic anticoagulation has been shown to reduce postoperative bleeding and requirements for allogeneic transfusions after cardiac surgery. However, some uncertainty exists whether this effect is due to the reduced amount of heparin or to the heparinized surface itself. Therefore, a retrospective study was undertaken, comparing two different anticoagulation protocols applied to coronary artery bypass patients treated with identical heparin-coated CPB equipment. METHOD: Over a 12 month period all coronary artery bypass patients operated with extracorporeal circulation were subjected to a Duraflo II heparin-coated circuit (Baxter Healthcare Corp, Bentley Laboratories Division, Irvine, Calif) and full heparin dose (activated clotting time [ACT] > 480 seconds; Group F, n = 651). Over the next 24 months, all coronary patients who were treated with an identical circuit combined with reduced systemic heparinization (ACT > 250 seconds) were included in Group R (n = 675). Except for the different anticoagulation protocols, all treatment regimens before, during, and after the operation remained unchanged throughout the study period. RESULTS: There were no statistically significant differences in any major demographic or operative parameters. In Group R, the postoperative bleeding was mean 665 +/- 257 ml versus 757 +/- 367 ml in Group F (p < 0.0001), and the perioperative decrease in hemoglobin concentration was significantly lower in Group R (22 +/- 1.2 gm/L versus 25 +/- 1.3 gm/L, p < 0.0001). The time for postoperative ventilatory support was shorter in Group R (1.7 +/- 1.3 hours versus 1.9 +/- 1.1 hours in Group F, p = 0.0006), and the incidence of new episodes of atrial fibrillation after the operation was lower (26.4% in Group R versus 32.8% in Group F, p = 0.01). There were no significant differences in the incidences of perioperative myocardial infarction, stroke, transient neurological disturbances, physical rehabilitation, or mortality. No technical or coagulation problems were recorded in either group. CONCLUSION: The use of Duraflo II coated circuits for CPB combined with reduced anticoagulation decrease postoperative bleeding and hemoglobin loss compared with full heparin dose treatment. In addition, the intubation time was shorter and the incidence of postoperative atrial fibrillation was lower in the patients treated with low heparin doses.     

Impact of a phosphorylcholine-coated cardiac bypass circuit on blood loss and platelet function: a prospective, randomized study

Platelet dysfunction due to cardiopulmonary bypass (CPB) surgery increases the risk of bleeding. This study analyzed the effect of a phosphorylcholine (PC)-coated CPB circuit on blood loss, transfusion needs, and platelet function. We performed a prospective, randomized study at Strasbourg University Hospital, which included 40 adults undergoing coronary artery bypass graft surgery (CABG) (n = 20) or mitral valve repair (n = 20) using CPB. Patients were randomized either to PC-coated CPB or uncoated CPB (10 CABG patients and 10 mitral valve repair patients in each group). Blood loss and transfusion needs were evaluated intra- and postoperatively. Markers of platelet activation and thrombin generation were measured at anesthesia induction, at the beginning and end of CPB, on skin closure, and on days 0, 1, and 5. Comparisons were made by Student's t test or covariance analysis (significance threshold p < or = .05). Blood loss was significantly lower in the PC group during the first 6 postoperative hours (171 +/- 102 vs. 285 +/- 193 mL, p = .024), at the threshold of significance from 6-24 hours (p = .052), and similar in both groups after 24 hours. During CPB, platelet count decreased by 48% in both groups. There was no difference in markers of platelet activation, thrombin generation, or transfusion needs between the two groups. Norepinephrine use was more frequent in the control group (63% vs. 33%) but not significantly. PC-coating of the CPB surface reduced early postoperative bleeding, especially in CABG patients, but had no significant effect on platelet function because of large interindividual variations that prevented the establishment of a causal relationship.     

Usefulness of recombinant human erythropoietin in cardiac surgery with autologous blood transfusion]

The efficacy and method of administration of recombinant human erythropoietin (EPO) in adult cardiac surgical patients when given preoperatively was evaluated. We used EPO intravenously (iv) with 40 mg ferric oxide for a total of consecutive 47 patients. The patients were divided into group A (n = 14; EPO 200 IU/kg iv 3 times a week from 3 weeks prior to surgery to 2 weeks after surgery, donation of 800 ml) and group B (n = 33; EPO 200 IU/kg iv everyday from 8 days prior to surgery to 2 weeks after surgery, donation of 400 ml). Control groups were group AO (n = 11; donation of 835 +/- 33 ml from 14.8 days prior to surgery) and group BO (n = 7; donation of 406 +/- 34 ml at 7.3 days prior to surgery). All the EPO-treated patients received no homologous blood transfusion while 2 of patients in group BO received some homologous blood transfusion. A hemoglobin change between pre-donation and surgery was +0.14 +/- 1.3 (g/dl) in group A, +0.04 +/- 1.0 (g/dl) in group B, -1.7 +/- 1.3 (g/dl) in group AO and -1.0 +/- 0.6 (g/dl) in group BO. In a comparison of post-surgical hemoglobin levels between group A and group B, we demonstrated that the level in group B, +2.1 +/- 1.8 (g/dl) was significantly higher than that in group A, +11.1 +/- 1.6 (g/dl) 2 weeks after surgery. There was no evidence to show an aggravation of anemia in the pre-surgical period in EPO-treated groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reinfusion of autologous platelet-rich plasma improves hemostasis after cardiopulmonary bypass]

Although it is reported that postoperative bleeding is reduced by reinfusing autologous platelet-rich plasma (PRP) after cardiopulmonary bypass (CPB), the effect of PRP on hemostasis is not reported in detail. We prepared PRP and fresh whole blood (WB) from the blood of seven patients each prior to their undergoing CPB, and reinfused them autologously to the patients intravenously after the CPB was terminated. In this article, the effect on hemostasis of autologous PRP and WB was described. Platelet aggregation rates and blood coagulation factors were examined before, during and after bypass. Platelet counts, ADP-induced platelet aggregation and the activities of coagulation factors II, V and VII-X were significantly greater in prepared PRP than in WB (p less than 0.01 or p less than 0.05). A mean volume of 724 +/- 109 ml of PRP or 401 +/- 63 ml of WB was reinfused within about 30 minutes after heparin was neutralized by protamine sulfate. The platelet counts increased from 4.3 +/- 1.4 x 10(4)/mm3 to 14.1 +/- 1.6 x 10(4)/mm3 after PRP reinfusion and the platelet aggregation rates increased significantly (p less than 0.01) after PRP reinfusion compared to WB transfusion. The activities of coagulation factors VII-X also increased significantly (p less than 0.05) after reinfusion of PRP when compared to transfusion of WB. The activated partial thromboplastin time decreased to 1.2 times the baseline in the PRP group but remained 1.5 times the baseline in the WB group (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Preoperative autologous blood donation in patients undergoing open heart surgery

We examined the possibility to avoid the homologous blood transfusion in patients undergoing open heart surgery by predonation of 200 ml or 400 ml on the day before operation. Between March 1999 and December 2001, 117 patients underwent scheduled open heart surgery. In these patients, preoperatively collected autologous blood on the day before operation amounted 200 ml or 400 ml. We divided these patients into 3 groups according to the necessity of homologous blood, no transfusion (group A, n = 77), intraoperative transfusion (group B 1, n-29) and postoperative transfusion (group B 2, n = 11). In 65.8% of patients the homologous blood transfusion could be avoided. Preoperative, intraoperative and postoperative factors were compared in the 3 groups. Especially, old age, female, body weight and preoperative hemoglobin value were significantly different between 3 groups. Postoperative Svo2 and postoperative hemoglobin value were significantly different between 3 groups. The purpose of this study was to evaluate that the predonation of 200 ml or 400 ml on the day before operation may be to avoid the homologous blood transfusion and that preoperative, intraoperative and postoperative factors in regard to homologous blood transfusion.     

Usefulness of tranexamic acid in cranial remodeling surgery

OBJECTIVES: To assess the usefulness of tranexamic acid (TA) in pediatric cranial remodeling surgery, by analyzing its effects on bleeding and transfusion requirements, number of days of cranial drainage required, and time spent in the postoperative recovery unit. MATERIAL AND METHOD: A single-blind, controlled study was designed with 20 patients (10 cases and 10 controls) randomly assigned to receive or not receive 15 mg/kg of intravenous TA upon anesthetic induction, every 4 hours during surgery, and every 8 hours throughout the 48 hours after surgery. Variables analyzed were results of blood tests, blood loss, volume transfused, time in the recovery unit, and complications related to TA infusion. RESULTS: The group treated with TA experienced less bleeding during surgery than did the controls (199 +/- 60 vs 290 +/- 43 mL) and had less need of intraoperative (176 +/- 104 vs 206 +/- 70 mL) and postoperative transfusion (9 +/- 28 vs 52 +/- 72 mL) 24 hours after surgery. TA group patients also spent less time in the recovery unit (60 +/- 14 vs 72 +/- 11 hours). Blood test variables in TA-treated children were also better 24 hours after surgery with regard to hemoglobin (12.1 +/- 2 vs 11.6 +/- 1.3 mg/dL) and platelet (261 +/- 68.5 vs 181.6 +/- 58.1 platelets/mm3) concentrations, and cephalin time (33 +/- 12 vs 49 +/- 16 seconds). No complications related to TA treatment were observed. CONCLUSIONS: TA can reduce perioperative bleeding in the context of pediatric cranial remodeling surgery. TA-treated patients have less need of transfusion and this may reduce the rate of related complications as well a make care more efficient.     

Heparin-coated Cardiopulmonary Bypass Circuits in Coronary Bypass Surgery

Abstract: Cardiopulmonary bypass (CPB) is a nonphysiologic environment for an organism. The damage of blood components may also lead to organ dysfunction, sometimes recognized as postperfusion syndrome. One possible way to diminish the risk of these complications would be to reduce the thorombogenicity and to improve the biocompatibility of the artificial surfaces by using a heparin-coated CPB circuit. In this study, we compared a heparin-coated CPB circuit with a noncoated CPB circuit in terms of biocompatibility in 20 patients undergoing elective coronary bypass surgery. We employed a Dura-flo II (n = 10) as a heparin-coated CPB circuit and a Univox IC (n = 10) as control subjects. Ten patients (Group C) were operated on using the heparin-coated CPB circuit. A total of 10 patients were given heparin in a reduced dose (2.0 mg/kg), and additional heparin was given if the activated clotting time (ACT) was below 400 s. The control group also included 10 patients (Group NC), who were operated on with noncoated devices. They received 2.5 mg/kg of heparin, and additional heparin was given if the ACT was below 450 s. All patients had normal coagulation parameters and did not receive blood transfusion. We measured complement activation levels (C3a, C4a), platelet count, thrombin-antithrombin III complex levels, D-dimer levels, and ACT during CPB and respiratory index postoperatively. The concentration of C3a in group NC was significantly higher than that in group C. Platelet reduction in group NC was significantly greater than that in group C. There were no significant differences in the remaining parameters between the 2 groups. We concluded that heparin-coated CPB circuits improved biocompatibility by reducing complement activation and platelet consumption and enabled us to reduce the dose of heparin required for systemic heparinization.