A comparison of haemostatic biomarkers during low-risk patients undergoing cardiopulmonary bypass using either conventional centrifugal cell salvage or the HemoSep device.

BACKGROUND: Cardiac surgery using cardiopulmonary bypass (CPB) is associated with a coagulopathy due to haemodilution, thrombocytopenia and platelet dysfunction and the activation of coagulation and fibrinolysis, despite the use of large doses of unfractionated heparin. Conventional red cell salvage may exacerbate post-operative bleeding as plasma containing haemostatic factors is discarded. We hypothesized that a novel cell salvage device (HemoSep) may attenuate haemostatic changes associated with red cell salvage. We studied haemostatic markers following autologous transfusion from conventional cell salvage or the HemoSep device. METHODS: This randomised, controlled trial compared haemostatic markers in patients undergoing coronary artery bypass grafting or aortic valve replacement who received autologous blood returned from cell salvage (control) or HemoSep (study). Blood samples were taken pre-operatively, end of CPB, post-transfusion of salvaged blood and 3 hours post-operatively and analysed for full blood count (FBC), prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, D-dimer and endogenous thrombin potential (ETP). RESULTS: Fifty-four patients were recruited (n=28 control, n=26 study). Processed blood volume for transfusion was significantly (p<0.001) higher in the HemoSep group. In the HemoSep group, the PT was shorter (18.7±0.3 vs 19.9±0.3 sec; p<0.05) post-operatively and the aPTT was longer (48.6±3.8 vs 37.3±1.0 sec; p<0.01) following autologous transfusion. In the control group, D-dimer and ETP levels were higher (1903±424 vs.1088±151; p<0.05 and 739±46 vs. 394±60; p<0.001, respectively) following autologous transfusion. CONCLUSIONS: Although centrifuged cell salvage is known to adequately haemoconcentrate and remove unwanted substrates and bacteriological contamination, the process can exacerbate coagulopathy. The HemoSep device demonstrated some increase in haemostatic markers when used in low-risk cardiac surgery patients.

Retrograde Autologous Priming as a Safe and Easy Method to Reduce Hemodilution and Transfusion Requirements during Cardiac Surgery.

BACKGROUND: During the last decades many efforts have been made to reduce transfusion requirements and adverse clinical effects during cardiopulmonary bypass (CPB). The minimal extracorporeal circulation (MECC) system and the technique of retrograde autologous priming (RAP) of a conventional CPB circuit have been associated with decreased hemodilution. Our study aimed to compare conventional CPB (cCPB), RAP, and the ROCsafe MECC (Terumo Europe N.V., Leuven, Belgium) system in elective coronary artery bypass patients. PATIENTS AND METHODS: Data were retrospectively collected on three cohorts of 30 adult CPB patients. Patients were operated using cCPB, RAP, and the ROCsafe MECC system. RESULTS: The three groups were comparable in demographic data. The priming volume in the ROCsafe and RAP group was significantly less compared with the conventional priming group (p <0.05). The mean time of extracorporeal circulation and aortic cross-clamp time (p <0.05) were significantly shorter in the ROCsafe group. The levels of hemoglobin (Hb) and hematocrit (Hct) during CPB and postoperatively showed significant differences between the three groups (p < 0.05) and resulted in significantly higher blood transfusion requirements (p < 0.05). Lactate, serum creatinine, troponin, and creatine kinase-myocardial band (CK-MB) levels did not differ significantly among the three groups (p >0.05). There was also no statistically significant difference in ventilation time, intensive care unit (ICU) stay, overall hospital stay, and postoperative complications (p >0.05). CONCLUSION: In conclusion, RAP is compared with cCPB and MECC a safe and low-cost technique in reducing the priming volume of the CPB system, causes less hemodilution, and reduces the need for intra- and postoperative blood transfusion.

Changes in mechanical fragility and free hemoglobin levels after processing salvaged cardiopulmonary bypass circuit blood with a modified ultrafiltration device.

Modified ultrafiltration (MUF) is available for the salvage of post-cardiopulmonary bypass circuit blood. This study evaluated the extent of hemolysis, the mechanical fragility index (MFI), and the amount of plasma free hemoglobin (PFHb) created after processing with the MUF device. Several RBC parameters were measured on pre- and post-MUF device processed samples of blood from 12 patients undergoing cardiac surgery. The MFI and total amount of PFHb did not change significantly between the pre- and post-processing samples: MFI, pre: .19 +/- .06 versus post: .19 +/- .06, p = .76; total amount of PFHb, pre: .24 +/- .21 g versus post: .20 +/- .12 g, p = .42. There was significantly more hemolysis in the post-processing samples compared with the pre-processing samples, .33 +/- .24% versus .96 +/- .48%, respectively, p < .001. Although percent hemolysis was increased following processing with the MUF device, the total amount of PFHb and RBC sublethal injury were not increased. The clinical significance of these findings needs to be determined.

Retrograde autologous priming in cardiopulmonary bypass in adult patients: effects on blood transfusion and hemodilution / Perfusato autólogo retrógrado no circuito de circulação extracorpórea em pacientes adultos: efeitos sobre a hemodiluição e transfusão de sangue

INTRODUCTION: Retrograde autologous priming (RAP) is a cardiopulmonary bypass (CPB) method, at low cost. Previous studies have shown that this method reduces hemodilution and blood transfusions needs through increased intra-operative hematocrit. OBJECTIVE: To evaluate RAP method, in relation to standard CPB (crystalloid priming), in adult patients. METHODS: Sixty-two patients were randomly allocated to two groups: 1) Group RAP (n = 27) of patients operated using the RAP and; 2) Control group of patients operated using CPB standard crystalloid method (n = 35). The RAP was performed by draining crystalloid prime from the arterial and venous lines, before CPB, into a collect recycling bag. The main parameters analyzed were: 1) CPB hemodynamic data; 2) Hematocrit and hemoglobin values; 3) The need for blood transfusions. RESULTS: It was observed statistically significant fewer transfusions during surgery and reduced CPB hemodilution using RAP. The CPB hemodynamic values were similar, observing a tendency to use lower CPB flows in the RAP group patients. CONCLUSION: This investigation was designed to be a small-scale pilot study to evaluate the effects of RAP, which were demonstrated concerning the CPB hemodilution and blood transfusions.

INTRODUÇÃO: Perfusato autólogo retrógrado (PAR) é uma técnica de circulação extracorpórea (CEC) com baixos custos. Estudos anteriores demonstraram que esta técnica reduz a hemodiluição e a necessidade de transfusões de sangue por meio do aumento do hematócrito intraoperatório. OBJETIVO: Avaliar técnica de PAR em relação à CEC técnica padrão (perfusato cristaloide) em pacientes adultos. MÉTODOS: Sessenta e dois pacientes foram aleatoriamente alocados em dois grupos: 1) Grupo PAR (n = 27), constituído por pacientes operados utilizando a técnica de PAR e; 2) Grupo Controle, constituído por pacientes operados utilizando técnica padrão de CEC com cristaloides (n = 35). A PAR foi realizada drenando-se o perfusato cristaloide das linhas arterial e venosa, antes da CEC, para uma bolsa coletora de recirculação. Os principais parâmetros analisados foram: 1) parâmetros hemodinâmicos da CEC; 2) valores de hematócrito e hemoglobina; e; 3) necessidade de transfusões de sangue. RESULTADOS: Observaram-se diferenças estatisticamente significativas de transfusão no intraoperatório e diminuição da hemodiluição em CEC utilizando PAR. Os valores hemodinâmicos durante a CEC foram semelhantes, observando-se tendência de utilização de fluxos menores na CEC dos pacientes do grupo PAR. CONCLUSÃO: O presente estudo foi projetado em pequena escala para avaliar os efeitos do PAR, o que foi demonstrado em relação aos já conhecidos efeitos na diminuição da hemodiluição em CEC e transfusão sanguínea, porém não mostrou vantagens hemodinâmicas em relação à técnica padrão com perfusato cristaloide.

Retrograde autologous priming in cardiopulmonary bypass in adult patients: effects on blood transfusion and hemodilution.

INTRODUCTION: Retrograde autologous priming (RAP) is a cardiopulmonary bypass (CPB) method, at low cost. Previous studies have shown that this method reduces hemodilution and blood transfusions needs through increased intra-operative hematocrit. OBJECTIVE: To evaluate RAP method, in relation to standard CPB (crystalloid priming), in adult patients. METHODS: Sixty-two patients were randomly allocated to two groups: 1) Group RAP (n = 27) of patients operated using the RAP and; 2) Control group of patients operated using CPB standard crystalloid method (n = 35). The RAP was performed by draining crystalloid prime from the arterial and venous lines, before CPB, into a collect recycling bag. The main parameters analyzed were: 1) CPB hemodynamic data; 2) Hematocrit and hemoglobin values; 3) The need for blood transfusions. RESULTS: It was observed statistically significant fewer transfusions during surgery and reduced CPB hemodilution using RAP. The CPB hemodynamic values were similar, observing a tendency to use lower CPB flows in the RAP group patients. CONCLUSION: This investigation was designed to be a small-scale pilot study to evaluate the effects of RAP, which were demonstrated concerning the CPB hemodilution and blood transfusions.

Circulating particles during cardiac surgery.

Shed blood is known to be a source of lipid micro-emboli in cardiac surgery. The aim of this study was to characterize the occurrence of these particles at different stages of the operation, and to study their occurrence in the circulation at multiple time-points after the retransfusion of shed blood. Forty-four patients undergoing routine surgery with cardiopulmonary bypass were included. Blood was sampled from the surgical field at different sampling locations during the operation. Shed blood was collected in a transfusion bag and retransfused. After which, blood was sampled from the arterial line of the heart-lung machine. A Coulter counter was used for particle determinion. The mean volume of shed blood collected was 340+/-215 ml. Particles in the size range 10-60 microm were found at varying concentrations, with the highest concentrations being found in blood collected after cannulation and from the pleura. After retransfusion of this blood, a biphasic response was seen in the blood drawn from the efferent line of the heart-lung machine. Particles are found in shed blood at all times during cardiac surgery, and when this blood was retransfused an increase was seen in particle concentration in the heart-lung machine.

The impact of allogenic red cell transfusion and coated bypass circuit on the inflammatory response during cardiopulmonary bypass: a randomized study.

OBJECTIVES: This study is designed to determine and compare the effects of transfusion and coated circuits on the inflammatory response during cardiopulmonary bypass. METHODS: Forty patients were randomized into two groups according to the type of extracorporeal circuit used and later prospectively enrolled into two subgroups according to the need for red cell transfusion during CPB (leading to 4 groups--10 patients per group; group 1: with no transfusion and standard oxygenator, group 2: with transfusion and standard oxygenator, group 3: with no transfusion and coated oxygenator, group 4: with transfusion and coated oxygenator). Serum lactate, interleukin 6, human tumor necrosis factor alpha (TNF-alpha), D-dimer and CRP levels were measured at three time points (T1: start of CPB, T2: before removal of aortic cross-clamp, T3: 45 min after the completion of proximal anastomoses). Protein adsorption of oxygenator fibers was measured. Outcome parameters were recorded. RESULTS: Interleukin 6, TNF-alpha, D-dimer and lactate levels increased at T2 and T3 in all groups (P<0.05 within groups). The increase in interleukin 6 was significant at T2 in group 2 when compared to group 1 (8.0+/-3.9 vs. 4.4+/-1.8, P=0.03). The increase in TNF-alpha was higher at T2 in group 1 when compared to group 3 (16.0+/-4.2 vs. 11.7+/-2.8, P=0.05) and in group 2 when compared to group 3 at T2 and T3 (15.3+/-4.6 vs. 11.7+/-2.8, P=0.06; 17.6+/-5.0 vs. 13.7+/-3.9, P=0.06). Protein adsorption was higher in group 1 and group 2 (group 1 vs. group 3, 2.2+/-0.8 vs. 1.4+/-0.3, P=0.01; group 2 vs. group 3, 2.4+/-0.7 vs. 1.4+/-0.3, P=0.02; group 2 vs. group 4, 2.4+/-0.7 vs. 1.8+/-0.3, P=0.04), it was also higher at group 4 when compared to group 3 (1.8+/-0.3 vs. 1.4+/-0.3, P=0.03). CONCLUSIONS: Allogenic red cell transfusion enhances inflammatory response during CPB; coated circuit systems have a limiting effect on this inflammatory reaction.

Transfusion-free arterial switch operation in a 1.7-kg premature neonate using a new miniature cardiopulmonary bypass system.

In cardiac surgery, the potentially detrimental effects of transfusions on patient outcome are increasingly appreciated. Therefore, at our institution there are continuing efforts to modify our surgical, perfusion, and blood management strategies with the aim of transfusion-free cardiac surgery even in neonates and small children. Stringent improvement of these strategies, particularly the downsizing of the cardiopulmonary bypass system, have now enabled a transfusion-free arterial switch operation in a 1700-gram prematurely born neonate.

On-line autotransfusion waste calculator.

Cell concentrating and washing techniques are widely accepted and believed to be beneficial to cardiac surgery patients. During cell processing, platelets, proteins, and clotting factors are wasted as the plasma is washed away by saline. Beneficial and costly plasma constituents are sacrificed for the sake of removing potentially harmful drugs, debris, and naturally activated cells and chemical mediators. An interactive Microsoft Excel spreadsheet was designed to input patient and autotransfusion system (ATS) reservoir blood values, processed centrifugal bowl data, and hospital allogeneic blood product concentration and cost information. The spreadsheet calculates the number of wasted platelets, grams of protein, and milligrams of fibrinogen. The calculator further estimates the number of units and cost of allogeneic blood products needed to replace the wasted blood components. The simulation allows for variable levels of platelet activation and protein removal during centrifugal cell processing. Specific case scenarios may be simulated with the calculator. If a known volume of residual extracorporeal circuit blood with a known hematocrit, platelet count, and protein concentration is diverted to the ATS reservoir to be processed and washed after bypass, the number of units of fresh frozen plasma, platelet packs, and albumin concentrate needed to replace the wasted proteins and platelets may be calculated. When typical end-bypass patient and blood bank product values are input, the cost to replace the wasted blood components in 1550 mL of residual circuit blood with allogeneic blood products is about US $2097. There are risks and costs associated with replacing the platelets, proteins, and clotting factors wasted during cell washing compared with other techniques such as whole blood ultrafiltration.

Effects of modified ultrafiltration on coagulation as measured by the thromboelastograph.

Hemodilution during cardiopulmonary bypass (CPB) continues to be a cause of morbidity associated with coagulation dysfunction, bleeding, and allogeneic blood transfusion. Clot formation and strength have been shown to impact bleeding and transfusions. Strategies to reduce hemodilution may be negated based on the course of the cardiac procedure itself. Modified ultrafiltration (MUF) is commonly used in pediatric cardiac surgery; however, it is not well accepted in adult surgery. This study aimed to evaluate clot formation and strength, bleeding, and transfusions in adult subjects undergoing MUF. Nineteen subjects having primary coronary artery bypass, aortic, or mitral valve surgeries were recruited and randomized to having MUF (n = 10) or no-MUF (n = 9) performed after the termination of CPB. Five time points for data collection were designated: T1, baseline/induction; T2, termination CPB; T3, post-MUF; T4, post-protamine; T5, 24 hours postoperative. Subjects randomized to MUF had 1505 +/- 15.8 mL of effluent removed, and no-MUF subjects had the CPB remnants processed with a cell salvage device. There was no statistical difference seen in 24-hour chest tube output, thromboelastograph values, or allogeneic transfusions at any time point between MUF and no-MUF subjects. There was a significant difference between MUF and no-MUF in the number of autologous cell salvage units processed (1.3 +/- .48 vs. 2.9 +/- .78, p = .0013) and end of procedure net fluid balance (+2003 +/- 1211 vs. +4194 +/- 1276 mL, p = .001), respectively. Estimated plasma loss from the cell salvage device was 477.6 mL greater in the no-MUF group. In primary adult cardiac procedures, MUF did not change coagulation values as measured by thromboelastography, number of allogeneic unit transfusions, or chest tube output at 24 hours postoperatively. There was a significant difference in autologous cell salvage units processed and end of procedure net fluid balance that benefited MUF subjects.

Autotransfusion management during and after cardiopulmonary bypass alters fibrin degradation and transfusion requirements.

UNLABELLED: The coagulation-fibrinolytic profile during cardiopulmonary bypass (CPB) has been widely documented. However, less information is available on the possible persistence of these alterations when autotransfusion is used in management of perioperative blood loss. This study was designed to explore the influence of autotransfusion management on intravascular fibrin degradation and postoperative transfusions. Thirty patients, undergoing elective primary isolated coronary bypass grafting, were randomly allocated either to a control group (group A; n=15) or an intervention group (group B; n=15) in which mediastinal and residual CPB blood was collected and processed by a continuous autotransfusion system before re-infusion. Intravascular fibrin degradation as indicated by D-dimer generation was measured at five specific intervals and corrected for hemodilution. In addition, chest tube drainage and need for homologous blood were monitored. D-dimer generation increased significantly during CPB in group A, from 312 to 633 vs. 291 to 356 ng/mL in group B (p = .001). The unprocessed residual blood (group A) revealed an unequivocal D-dimer elevation, 4131 +/- 1063 vs. 279 +/- 103 ng/mL for the processed residual in group B (p < .001). Consequently, in the first post-CPB period, the intravascular fibrin degradation was significantly elevated in group A compared with group B (p = .001). Twenty hours postoperatively, no significant difference in D-dimer levels was detected between both groups. However, a significant intra-group D-dimer elevation pre- vs. postoperative was noticed from 312 to 828 ng/mL in group A and from 291 to 588 ng/mL in group B (p < .01 for both). Postoperative chest tube drainage was higher in the patients from group A, which also had the highest postoperative D-dimer levels. Patients in group A perceived a higher need for transfusions of red cells suspensions postoperatively. These data clearly indicate that autotransfusion management during and after CPB suppresses early postoperative fibrin degradation. KEYWORDS: cardiopulmonary bypass, cardiotomy suction, coronary surgery, autotransfusion, fibrin degradation.

Improved coagulation and blood conservation in the golden hours after cardiopulmonary bypass.

The Hemobag (HB) technique allows the open-heart team to safely concentrate the residual cardiopulmonary bypass (CPB) circuit contents and return a high volume of concentrated clotting factors and blood cells back to the patient as autotransfusion. Hematocrit, platelet count, fibrinogen concentration ([Fib]), prothrombin time (PT), partial thromboplastin time (PTT), and international normalized ratio (INR) were compared between two prospective convenience groups of cardiac surgical patients whose residual circuit blood was processed by the HB (n=10) or by the Cell Saver (CS; n=10) at two times after CPB: (a) after acute normovolemic hemodilution (ANH) infusion and protamine administration and (b) after admission to the intensive care unit (ICU), approximately 1 hour after CPB and HB content infusion. Minimal cell processing was also used in the HB patients to conserve blood. "Golden hours" is defined as the first few hours after CPB and protamine sulfate administration and extend into the ICU, when maintaining hemostasis is vital during cardiac surgery and is the most susceptible period for blood product administration and the opportunity to improve patient outcome. Except for PTT, all parameters changed significantly from the ANH infusion and protamine administration to approximately 1 hour after HB blood infusion and arrival in the ICU. Fibrinogen (p = .048) and hematocrit (p = .046) were significantly higher in the HB group compared with the CS group at the end of the golden hour despite infusion of significantly more allogeneic blood products (p = .070) and more washed red blood cells (RBCs; p = .001) in the CS group. All but one of the HB patients did not receive any allogeneic blood products during the golden hours. Use of the HB technique for salvaging blood is associated with significant increases in the patient's protein and cellular concentrations and lowered coagulation times in the important, first few golden hours after CPB, and except for one patient, without the addition of expensive and precarious allogeneic blood products.

Clinical advantages of using mini-bypass systems in terms of blood product use, postoperative bleeding and air entrainment: an in vivo clinical perspective.

OBJECTIVE: In an effort to minimize the effect of extracorporeal circulation (ECC), mini-bypass is gaining clinical acceptance in routine coronary artery bypass grafting (CABG). These small circuits target combine the clinical advantages of reduced prime, 100% bio-coating and suction blood separation. We demonstrate that the use of mini-bypass in routine CABG reduces homologous blood product use and postoperative bleeding. Our goal was to also demonstrate that these small systems are effective in gaseous microemboli (GME) management as compared to a conventional extracorporeal system. METHODS: Prospective, randomized study comparing 30 mini-bypass (Dideco ECC.O) to 30 conventional systems (n=30, Dideco 903 Avant). Study included CABG cases only, independent of preoperative coagulative status; clinic ethical committee approval and informed patient consent was obtained before initiating study. RESULTS: There were no statistical differences in terms of patient demographics. Statistically significant differences were seen in transfusion frequency (27% of the study group vs 43% in the control group, p=0.05), transfused volume (133.3+/-244.5 ml vs 325+/-483.1 ml, p<0.05), fresh frozen plasma (0 unit vs 3 units, p<0.001), postoperative bleeding (301.8+/-531.9 ml vs 785.5+/-1000.4 ml, p<0.05) and GME activity post-arterial filter (0.14 microl vs 5.32 microl, p<0.05). CONCLUSIONS: The adoption of mini-bypass significantly potentially reduces hemodilution, donor blood usage, postoperative bleeding and exposure to GME in routine CABG patients as compared to the use of conventional extracorporeal circulation circuits.

An innovative simple technique of blood conservation in adult patients with tetralogy of Fallot and severely raised hemoglobin.

The adult patients of tetralogy of Fallot often present with high hemoglobin levels. High hemoglobin and hematocrit on cardiopulmonary bypass (CPB) are associated with increased hemolysis, plasma free hemoglobin, renal dysfunction or failure, postoperative bleeding, exploration for bleeding, and increased requirement of allogeneic blood and blood products. Despite the presence of high hemoglobin and its association with adverse outcome, blood conservation is rarely practiced in these patients because of the fear of possible hemodynamic instability, and hypoxemic spell. We describe an innovative, simple technique of blood conservation for adult patients of tetralogy of Fallot with severely raised hemoglobin. With this technique, hemoglobin can be normalized on CPB; moreover, there is no fear of hypoxemic spell or hemodynamic instability. Furthermore, the blood conserved is readily available for transfusion in the perioperative period, if needed.

A new practical technique to reduce allogeneic blood exposure and hospital costs while preserving clotting factors after cardiopulmonary bypass: the Hemobag.

Recent data independently linking allogeneic blood use to increased morbidity and mortality after cardiopulmonary bypass (CPB) warrants the study of new methods to employ unique and familiar technology to reduce allogeneic blood exposure. The Hemobag allows the open-heart team to concentrate residual CPB circuit contents and return a high volume of autologous clotting factors and blood cells to the patient. Fifty patients from all candidates were arbitrarily selected to receive the Hemobag (HB) therapy. A retrospective control group of 50 non-Hemobag (NHB) patients were matched to the HB group patient-by-patient for comparison according to surgeon, type of procedure, age, body surface area (BSA), body weight and CPB time. Many efforts to conserve blood (Cell Saver and ANH) were employed in both groups. Post-CPB cell washing of circuit contents was additionally employed in the control group. There were no significant differences between the HB and NHB groups in regard to patient morphology, pre-op cell concentrations, distribution of surgeon or procedures (41% valve, 16% valve/coronary artery bypass graft (CABG), balance CABG), pump and ischemic times and Bayes National Risk scores. The average volume returned to the patient from the HB was 817+/-198 mL (1 SD). Average processing time was 11 min. The Hemobag contained an average platelet count of 230+/-80 K/mm3, fibrinogen concentration of 413 +/- 171 mg/dl, total protein of 8.0+/-2.8 gm/dl, albumin of 4.4+/-1.2 gm/dl and hematocrit of 43+/-7%. Factor VII, IX and X levels in three HB contents averaged 259% greater than baseline. Substantial reductions were achieved in both allogeneic blood product avoidance and cost to the hospital with use of the HB. Infusion of the Hemobag concentrate appears to recover safely substantial proteins, clotting factor and cell concentration for all types of cardiac procedures, maintaining the security of a primed circuit.

Particle separation using ultrasound can be used with human shed mediastinal blood.

BACKGROUND: Shed mediastinal blood collected by cardiotomy suction has been shown to be a large contributor to lipid microemboli ending up in different organs. The aim of this study was to test the separation efficiency on human shed blood of a new separation method developed to meet this demand. METHODS: Shed mediastinal blood collected from the pericardial cavity of 13 patients undergoing cardiac surgery with cardiopulmonary bypass was collected. The blood was processed in an eight-channel parallel PARSUS separator, and separation efficiency was determined. RESULTS: Erythrocyte recovery, in terms of a separation ratio, varied between 68% and 91%. Minor electrolyte changes took place, where levels of sodium increased and levels of potassium and calcium decreased. CONCLUSION: This study demonstrates that PARSUS technology can be used on human shed mediastinal blood with good separation efficiency. The technology is, thereby, suggested to have future clinical relevance.

Platelet activity of residual blood remained in the cardiopulmonary bypass circuit after cardiac surgery.

AIM: We measured the platelet count and platelet function in residual blood in the cardiopulmonary bypass (CPB) circuit after cpb and compared them with data before CPB operation. METHODS: The subjects included 34 cases of patients subjected to CPB surgery. The residual blood was concentrated by ultrafiltration after CPB, collected in the bag and the platelet count and platelet activity was measured. ADP 2, 5, 10 microM was used as agonists and measurement was made by turbidimetry. RESULTS: The mean value of the platelet count was 18.3+/-5.65x10(4)/mm(3) before surgery and 17.2+/-8.39x10(4)/mm(3) in the residual blood, there is no difference. Concerning the platelet aggregation activity, the maximum aggregation rate decreased significantly with ADP 2 microM from 47.4+/-19.6% before surgery to 27.1+/-17.2% in the residual blood (p<0.01). Likewise, it decreased significantly with ADP 5 and 10 microM. The reduction rate of the platelet aggregation activity was higher in the group of not less than 100 minutes compared with the group of less than 100 minutes, but no significant difference was found. CONCLUSION: Autotransfusing whole blood per se without the "cell saver" treatment is more advantageous to keep hemostasis function after surgery since many platelets having the aggregation activity exist in residual blood in the CPB circuit.