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1.
Background. The purpose of our review was to develop simple clinical recommendations to reduce the need for allogeneic blood transfusions in children undergoing cardiac operations.

Methods. The literature on hemostasis as it relates to children, cardiac disease in children, and pediatric heart surgery was reviewed. We also reexamined the efficacy of several strategies in this patient population: on-site monitoring of coagulation, transfusion of fresh whole blood, and administration of desmopressin, ε-aminocaproic acid, or aprotinin.

Results. Children with heart disease may present with preoperative thrombocytopenia, reduced platelet aggregation, and a decreased level of von Willebrand factor. Infants less than 6 months of age show a significant dilution of coagulation factors and decreased platelet counts during cardiopulmonary bypass. Fresh whole blood reduces blood loss in children younger than 2 years undergoing complex operations. Desmopressin does not reduce bleeding, whereas on-site monitoring, synthetic antifibrinolytics, and aprotinin require further evaluation in pediatric cardiac surgical patients.

Conclusions. The use of fresh whole blood to reduce blood loss in children younger than 2 years undergoing complex heart operations is recommended. Therapy for excessive bleeding after cardiopulmonary bypass will vary according to the patient's age, platelet count, and activated partial thromboplastin and prothrombin times.  相似文献   


2.
Coagulation is a complex process that allows whole blood to form clots at tissue and vessel sites where damage has occurred. Activation of the hemostasis system causes platelets and fibrin-containing clot to stop the bleeding. Perfusionists must find ways to preserve the coagulation system if we are to avoid bleeding in the cardiopulmonary bypass patient. It is still unclear what techniques are best to continue maintaining hemostasis and avoiding transfusion in patients requiring cardiopulmonary bypass (CPB). There are numerous factors that come into play with the use of CPB including deactivating the coagulation system with anticoagulants, hemodilution of the circulating blood volume, inflammatory response, and a possible pro-coagulant response from protamine with heparin reversal once the surgical procedure has been completed and CPB terminated. All these factors make achieving hemostasis post CPB extremely difficult. This review attempts to assess what is currently being discussed in the literature, which may improve hemostasis with cardiopulmonary bypass. There is still no one technique that will improve hemostasis post CPB. Perhaps the answer may lie in a combination of reported techniques that may in some way lead to the preserving of coagulation factors during CPB.  相似文献   

3.
BACKGROUND: Postoperative bleeding and blood product requirements can be substantial in children undergoing open-heart surgery, and reexploration is required in 1% of cases. Recombinant activated factor VII (rFVIIa, NovoSeven, NovoNordisk, Denmark) is a hemostatic agent approved for the treatment of hemophilic patients with inhibitors to factor VIII or factor IX. It has also been used with success in other conditions. We present our experience with rFVIIa treatment for uncontrolled bleeding after open-heart surgery in five pediatric patients. METHODS: The study group consisted of five patients after open-heart surgery with excessive blood loss. The patients were treated with rFVIIa after failure of conventional treatment to control the bleeding. Blood loss, blood product consumption, and coagulation test results were recorded before and after rFVIIa administration. RESULTS: In all cases, blood loss decreased considerably after rFVIIa administration (mean 7.8 ml x kg(-1) x h(-1)), almost eliminating the need for additional blood products, and the prolonged prothrombin time normalized. In two patients with thrombocytopathy, rFVIIa helped to discriminate surgical bleeding from bleeding caused by a defect in hemostasis. No side effects of rFVIIa treatment were noted. CONCLUSIONS: These cases support the impression that RFVIIa is efficient and safe in correcting hemostasis in children after cardiopulmonary bypass when other means fail. However, the data are still limited, and more extensive research is needed.  相似文献   

4.

Purpose

This is a case report involving a middle-aged Jehovah??s Witness patient who underwent a redo aortic valve replacement, coronary artery bypass graft, and Maze procedure facilitated by cardiopulmonary bypass. The consent process included a discussion of the management of bleeding and hemostasis in the perioperative period in the context of the patients?? religious choice and the possible consequences of avoiding transfusion in massive bleeding. The medical team agreed to abide by the patient??s wishes with respect to the blood and blood products deemed unacceptable by the patient irrespective of the consequences. The consent included a discussion of manufactured hemostatic agents that are designated by the Hospital Liaison Committee Network for Jehovah??s Witnesses as subject to personal decision. There was also a discussion of recombinant agents available, all of which are acceptable to Jehovah??s Witness patients. The patient accepted the use of cryoprecipitate, prothrombin complex concentrate, and recombinant factor VIIa.

Clinical features

After separation from cardiopulmonary bypass and protamine administration, blood loss was 350?mL over a ten-minute period. The international normalized ratio (INR) was 3.5 at that time. Cryoprecipitate 15 U, 1-deamino-8-D-arginine vasopressin 16 U, and a prothrombin complex concentrate, Octaplex?, 60?mL were administered. Blood loss improved significantly. The INR in the cardiac surgical intensive care unit was 1.3. The sample was taken approximately one hour following the administration of the hemostatic agents. The patient??s chest was closed, and chest tube drainage was 310?mL over the next 12 hr.

Conclusion

This is a novel case involving the use of prothrombin complex concentrate in the setting of a Jehovah??s Witness patient undergoing a complex operative procedure.  相似文献   

5.
OBJECTIVES: Open heart surgery without homologous blood transfusion remains difficult in children. The introduction of vacuum-assisted cardiopulmonary bypass circuits to reduce priming volume for pediatric patients has improved the percentage of transfusion-free operations. We retrospectively analyzed blood transfusion risk factors to further reduce blood transfusion requirements after vacuum-assisted circuit introduction. METHODS: From March 1995 to June 1996, 49 patients weighing between 5 and 20 kg underwent cardiac surgery with cardiopulmonary bypass at our institution, excluding hospital deaths. We retrospectively analyzed risk factors influencing blood use in 37 patients with no blood priming in cardiopulmonary bypass after introducing a vacuum-assisted system. Factors selected for univariate analysis were age, body weight, cyanosis, preoperative Hb, operation time, cardiopulmonary bypass time, aortic cross-clamping time, and intraoperative and postoperative bleeding volume. Correlation between total bleeding volume/body weight and cardiopulmonary bypass time was studied by regression analysis. RESULTS: As risk factors, univariate analysis identified cyanotic disease, longer operation time (> 210 minutes), longer cardiopulmonary bypass time (> 90 minutes), longer aortic cross-clamping time (> 45 minutes), greater intraoperative bleeding volume/body weight (> 4 ml/kg), and greater postoperative bleeding volume/body weight (> 15 ml/kg). Regression analysis showed a significant positive correlation between total bleeding volume/body weight and cardiopulmonary bypass time. CONCLUSIONS: Cyanotic disease and long bypass time are risk factors in reducing blood transfusion requirements in pediatric open heart surgery after introduction of vacuum-assisted circuits. Further efforts are needed, however, to reduce blood transfusion requirements, particularly in these children.  相似文献   

6.
Postoperative bleeding is common in patients undergoing cardiac surgery with cardiopulmonary bypass. Most cases of severe postoperative bleeding not due to incomplete surgical hemostasis are related to acquired transient platelet dysfunction mediated by platelet activation during contact with the synthetic surfaces of the cardiopulmonary bypass equipment. Antihypertensive agents nitroglycerin and sodium nitroprusside have been shown to have platelet inhibitory properties, yet the clinical consequence in terms of postoperative bleeding has been little studied. Knowing that cardiopulmonary bypass causes platelet dysfunction, it is prudent for physicians to be aware of the additional platelet inhibition caused by these commonly used antihypertensive agents.  相似文献   

7.
Study Objective: To review the basic pathophysiology of altered coagulation associated with cardiopulmonary bypass and autologous blood transfusion in cardiac surgery.

Design: Review of rational use of heparin, mechanisms and treatment of coagulation disorders, and autologous blood transfusion.

Setting: Cardiac surgery in community and academic hospitals.

Patients: Adult cardiac surgical patients.

Main Results: Heparin is most commonly used for anticoagulation during cardiopulmonary bypass. Although activated clotting time is widely used to assess heparin-induced anticoagulation, the minimum time to prevent clotting during cardiopulmonary bypass remains unclear. Activated clotting time is affected by many factors other than heparin, such as antithrombin III, blood temperature, platelet count, and age. The rational use of activated clotting time still must be defined.

The frequency of abnormal bleeding after cardiopulmonary bypass is significant. Although inadequate surgical hemostasis is the most frequent cause of bleeding, altered coagulation often is present. A decreased number of functional platelets is one of the important causes of bleeding diathesis. Platelet dysfunction is induced by perioperative medication such as aspirin. Cardiopulmonary bypass decreases functional platelets by degranulation, fragmentation, and loss of fibrinogen receptors. Medications such as prostacyclin and iloprost may be useful to protect these platelets. Desmopressin increases factor VIII:C and von Willebrand's factor, leading to a decrease in bleeding time. Desmopressin may be useful to decrease blood loss in repeat cardiac operations, complex cardiac surgery, and abnormal postoperative bleeding.

Patients undergoing coronary artery bypass grafting immediately after streptokinase infusion also are at risk for abnormal bleeding. Transfusion of fresh frozen plasma and cryoprecipitate may be necessary.

Autologous blood transfusion is cost-effective and the safest way to avoid or decrease homologous blood transfusion. Predonation, intraoperative salvage, and postoperative salvage are encouraged. Erthroprotein may be useful in increasing the amount of predonation red cells.

Conclusions: Coagulation disorders in cardiac surgery are caused by many factors, such as heparin, platelet dysfunction, and fibronolysis. Rational use of blood component therapy and medications such as heparin, protamine, and desmorpessin are mandatory. Autologous blood transfusions is very useful in decreasing or obviating the use of homologous blood transfusion.  相似文献   


8.
Clopidogrel, an irreversible ADP-receptor antagonist, inhibits platelet aggregation mediated by reduced activation of glycoprotein receptor IIb/IIIa. Clopidogrel in combination with aspirin has been shown to be superior to aspirin alone for treating unstable angina, but clopidogrel recipients have shown increases in blood loss, transfusion requirements, and rate of reoperation after cardiac surgery. We describe a patient who had taken clopidogrel 75 mg daily until the day prior to coronary artery bypass graft surgery. Severe postoperative bleeding developed and was refractory to conventional hemostatic therapy consisting of 19 units of packed red blood cell concentrates, 16 of fresh frozen plasma, 8 of platelet apheresis concentrates plus high-dose treatment with aprotinin (500.000 kallikrein-inhibiting units/h) and administration of 0.3 microg/kg 1-deamino-8-D-arginine vasopressin (DDAVP). Two reoperations were performed, but surgical hemostasis was not achieved, so 100 microg/kg recombinant activated factor VII was applied to generate sufficient thrombin to stop the bleeding. This treatment approach reduced the bleeding. Then, to promote clot formation and firmness, 2 g of fibrinogen and 1250 IU of factor XIII were administered, and the bleeding finally stopped. No further transfusions were required, and the patient was discharged from the hospital on day 10 after the operation. This case suggests that in clopidogrel-related bleeding refractory to conventional hemostatic therapy, hemostasis may be achieved by a stepwise administration of coagulation factor concentrates.  相似文献   

9.
Prophylactic administration of platelet concentrates to patients undergoing their first cardiopulmonary bypass operation (coronary artery bypass grafting or uncomplicated valve replacement) was evaluated in a controlled randomized study of 28 patients. Four units of platelet concentrates administered at the end of bypass prevented prolongation of the bleeding time seen in patients not receiving platelets. However, chest tube blood loss, transfusion requirements, and clinical outcome were not improved. Moreover, thrombocytopenia and prolongation of bleeding time did not correlate with blood loss or transfusion needs. Mild thrombocytopenia (to 58,000 platelets per microliter) and transient platelet dysfunction after bypass do not require administration of platelet concentrates, and prophylactic use of this blood component in the surgical setting of bypass is not indicated.  相似文献   

10.
Mechanisms of bleeding common to virtually all patients after heart surgery are platelet dysfunction, enhanced fibrinolysis, dilution of all components of the coagulation system, and the presence of heparin and protamine. The use of warfarin is increasing in patients with heart disease requiring surgery. The replenishment of vitamin K-dependent factors beyond a normal prothrombin time is not assessable, and the dilution associated with cardiopulmonary bypass can reach coagulopathic levels. Optimal preoperative preparation is required and intraoperative therapy initiated when indicated. Individualized heparin and protamine dosing, antifibrinolytic drug administration, minimization of blood loss and dilution, and minimal time on cardiopulmonary bypass are basic adjuncts to meticulous surgical hemostasis. When bleeding is observed in the postoperative period, a sequential assessment of the probable cause leads to initial therapy while laboratory test results are obtained. Ongoing assessment for hemodynamic instability caused by accumulated mediastinal blood is needed while managing the bleeding patient. A chest radiograph and transesophageal echocardiogram can be useful in diagnosing cardiac tamponade.  相似文献   

11.
Fibrinolytic activation is a major and preventable source of bleeding in neonates and children undergoing cardiac surgery with cardiopulmonary bypass. Based on the existing literature (adult and pediatric; cardiac and noncardiac), prophylactic administration of antifibrinolytic agents can help reduce fibrinolytic activation, and consequently reduces perioperative bleeding and the requirement for blood product transfusion. Due to the increased risk of renal failure and mortality reported in adults undergoing cardiac surgery, aprotinin should not be considered as a safe option in neonates and children. Further well‐designed studies would be required before the prophylactic administration of aprotinin could be considered in pediatric cardiac surgery. The lysine analogs, tranexamic acid and ?‐aminocaproic acid,, should be considered as safe and effective antifibrinolytic agents. Although no major side effects have been reported following the administration of lysine analogs in children undergoing cardiac surgery, high‐dose tranexamic acid should not be recommended in order to avoid the increased risk of clinical seizures. Despite the recent advances made in our understanding of the pharmacokinetics of tranexamic acid and ?‐aminocaproic acid,, the optimal plasmatic concentration to be targeted remains unknown. Further studies are therefore urgently needed to better define the optimal dose regimen to be used in neonates and children. In the meantime, the dose regimen published in the most recent pharmacokinetic studies can be used. Although no studies have assessed the effect of massive bleeding and transfusion on the plasmatic concentrations of the lysine analogs, additional boluses might be considered in the presence of bleeding and/or when signs of fibrinolytic activations are observed on viscoelastic hemostatic assays.  相似文献   

12.
OBJECTIVE: To assess the effects of a single dose of tranexamic acid on bleeding and requirement for blood product transfusion in children undergoing cardiac surgery with cardiopulmonary bypass. PATIENTS AND METHODS: A prospective study of closed cohorts undergoing pediatric heart surgery was carried out. The children weighed between 4 and 10 kg. Reoperated and cyanotic patients were included in the sample. The treatment group received 50 mg x kg(-1) of tranexamic acid before surgery. Analyzed data collected during the first 24 hours after surgery were biochemical parameters, bleeding, use of blood products, and D-dimer levels. RESULTS: Fifty-three patients, 25 in the treatment group, were enrolled. Patients on treatment had 24.8% less bleeding in the first 24 hours after surgery (P = .02). The transfusion of blood products was 20% less in the treatment group, although the difference was not significant except in the subgroup of patients who were reoperated. In that group the amount of blood products transfused was 72% less than in the control group (P = .05). D-dimer levels were also lower in the treatment group (P = .003). No adverse effects attributable to the treatment were observed. CONCLUSIONS: A single preoperative dose of tranexamic acid to inhibit fibrinolysis reduces bleeding 24.8% in pediatric patients undergoing heart surgery with cardiopulmonary bypass. The effect is greater in reoperated patients, leading to a reduction in their requirement for transfusion. The use of this therapy in these patients is therefore highly justified.  相似文献   

13.
The rationale for predicting the risk of excessive postoperative bleeding by assessing the hemostatic status of a patient before cardiopulmonary bypass was investigated. A novel, rapid, overall test (hemostatometry) consisting of a physiologically relevant test of platelet function (shear-induced hemostasis) and coagulation was performed using nonanticoagulated blood and compared with the routine coagulation screen. Two hundred five patients undergoing elective coronary revascularization were studied 3 to 4 days before operation. Forty-nine bled excessively for nonsurgical reasons; none were predicted by the routine coagulation tests. Using a stepwise discriminant analysis, hemostatometry correctly predicted 31 of 49 (63%). Thirty of 156 predicted as bleeders by hemostatometry did not bleed. Thus, preoperative hemostatometry predicted 77% of the true outcome. The false predictions suggest, however, that certain bleeding abnormalities probably acquired during cardiopulmonary bypass cannot be predicted. These findings do not justify the routine use of preoperative tests in assessing the bleeding risk in patients undergoing cardiopulmonary bypass.  相似文献   

14.
Coagulopathy associated with massive operative blood loss is an intricate, multicellular and multifactorial event. Massive bleeding can either be anticipated (during major surgery with high risk of bleeding) or unexpected. Management requires preoperative risk evaluation and preoperative optimization (discontinuation or modification of anticoagulant drugs, prophylactic coagulation therapy). Intraoperatively, the causal diagnosis of the complex pathophysiology of massive bleeding requiring rapid and specific coagulation management is critical for the patient's outcome. Treatment and transfusion algorithms, based on repeated and timely point-of-care coagulation testing and on the clinical judgment, are to be encouraged. The time lapse for reporting results and insufficient identification of the hemostatic defect are obstacles for conventional laboratory coagulation tests. The evidence is growing that rotational thrombelastometry or modified thrombelastography are superior to routine laboratory tests in guiding intraoperative coagulation management. Specific platelet function tests may be of value in platelet-dependent bleeding associated e.g. with extracorporeal circulation, antiplatelet therapy, inherited or acquired platelet defects. Therapeutic approaches include the use of blood products (red cell concentrates, platelets, plasma), coagulation factor concentrates (fibrinogen, prothrombin complex, von Willebrand factor), pharmacological agents (antifibrinolytic drugs, desmopressin), and local factors (fibrin glue). The importance of normothermia, normovolemia, and homeostasis for hemostasis must not be overlooked. The present article reviews pathomechanisms of coagulopathy in massive bleeding, as well as routine laboratory tests and viscoelastic point-of-care hemostasis monitoring as the diagnostic basis for therapeutic interventions.  相似文献   

15.
After cardiac surgery with extracorporeal circulation, approximately 20% of patients show significant bleeding tendencies and 5% require re-intervention. In 50% of patients undergoing re-operation, no surgical cause can be determined, suggesting coagulopathy after cardiopulmonary bypass (CPB). For perioperative management of transfusion of blood products and coagulation factor concentrates, a clinical algorithm for the perioperative hemostatic therapy in patients undergoing cardiac surgery with CPB has been developed. The currently available evidence and the point of care methods routinely accessible in our institution (blood gas analysis, ACT, point of care Quick value, aPTT and platelet count) were used. The intervention with plasma products, coagulation factor concentrates and hemostatic drugs after extracorporeal circulation are described. Extensive bleeding history as well as the efficacy and side effects of antifibrinolytic treatment are discussed.  相似文献   

16.
Patients undergoing cardiac surgery with cardiopulmonary bypass are at risk for excessive microvascular bleeding, which often leads to transfusion of allogeneic blood and blood components as well as reexploration in a smaller subset of patients. Excessive bleeding after cardiac surgery is generally related to a combination of several alterations in the hemostatic system pertaining to hemodilution, excessive activation of the hemostatic system, and potentially the use of newer, longer-acting antiplatelet or antithrombotic agents. Although several nonpharmacologic strategies have been proposed, this review summarizes the role of pharmacologic interventions as means to attenuate the alterations in the hemostatic system during CPB in an attempt to reduce excessive bleeding, transfusion, and reexploration. Specifically, agents that inhibit platelets, fibrinolysis, factor Xa and thrombin, as well as broad-spectrum agents, have been investigated with respect to their role in reducing consumption of clotting factors and better preservation of platelet function. Prophylactic administration of agents with antifibrinolytic, anticoagulant, and possibly antiinflammatory properties can decrease blood loss and transfusion. Although aprotinin seems to be the most effective blood conservation agent (which is most likely related to its broad-spectrum nature), agents with isolated antifibrinolytic properties may be as effective in low-risk patients. The ability to reduce blood product transfusions and to decrease operative times and reexploration rates favorably affects patient outcomes, availability of blood products, and overall health care costs.  相似文献   

17.
We experienced the anesthetic management for cardiac surgery without the administration of protamine in a patient with severe food allergy. The patient, a 15-year-old boy, who had been avoiding many kinds of food including fish due to severe food allergy, received a correction of ventricular septal defect under cardiopulmonary bypass (CPB). To detect intraoperative drugs, including protamine, which might induce allergic reaction, we performed intradermal tests and prick tests. We used heparin-coated bypass circuit to minimize the amount of heparin necessary for anticoagulation during CPB. After CPB, hemostasis was achieved without the administration of protamine, and the patient received neither transfusion nor blood product throughout the perioperative period. Avoidance of protamine is advisable if the patient is allergic to food especially fish. The use of heparin-coated bypass circuit should be considered to establish hemostasis without protamine after CPB and to reduce blood products.  相似文献   

18.
Spontaneous bleeding is rare in patients with factor XI deficiency and significant bleeding usually occurs after a trauma or a surgical procedure. It is difficult to maintain hemostatic balance in these patients. In the present case report, a 68-year-old male patient with no chronic disease was scheduled for elective cardiopulmonary bypass surgery. Eight units of fresh-frozen plasma (FFP) were slowly infused and the operation was initiated with the activated partial thromboplastin time (aPTT) of 34.5, which was 108.7 in the preoperative period. Tranexamic acid bolus was administered before the skin incision and continued throughout the operation. Intraoperative aPTT was measured intermittently and a total of six units of FFP were administered. After 76 minutes of cross-clamp time, the patient was separated from cardiopulmonary bypass without any problem. There is no consensus regarding the management of bleeding during cardiac surgery in patients with factor XI deficiency. The common approach includes normalizing the factor levels via FFP infusion or factor concentrates in the preoperative period, proceeding with surgery following the replacement, and close monitoring of perioperative factor levels and aPTT values.  相似文献   

19.
Coronary artery bypass in hereditary factor XI deficiency   总被引:1,自引:0,他引:1  
Hereditary factor XI deficiency is a disorder of coagulation that has been associated with postoperative bleeding. Because cardiopulmonary bypass itself induces transient abnormalities in hemostasis, the patient with factor XI deficiency could be at increased risk for bleeding after cardiac surgical procedures. We report the successful management of a 61-year-old man with hereditary factor XI deficiency who had coronary artery bypass. Treatment with low-dose aspirin, begun 24 hours postoperatively for graft patency, was well tolerated. Once recognized and aggressively treated, factor XI deficiency does not appear to be a contraindication to potentially life-saving procedures like coronary revascularization.  相似文献   

20.
ObjectivesRecombinant activated factor VIIa (rVIIa) is used off-label for refractory bleeding after cardiac surgery. This study reviewed the indications, usage rates, and complications of rVIIa.DesignA retrospective case-control observational study.SettingA single quaternary pediatric hospital.ParticipantsAll children undergoing cardiac surgery with cardiopulmonary bypass over a three-year period.InterventionsAdministration of rVIIa as rescue therapy for refractory bleeding after weaning from cardiopulmonary bypass.Measurements and Main ResultsOnethousand, five hundred fifteen cardiopulmonary bypass procedures were reviewed. Patients receiving rVIIa were each matched to two control patients by age, procedure type, and bypass time. Data collected included weight, crossclamp time, anticoagulant and antifibrinolytic dose, return to the operating room for bleeding, thrombotic events, and extracorporeal membrane oxygenation (ECMO) circuit interventions.Forty-two patients received rVIIa (2.8%). Major systemic thrombotic complications were observed in 19% (controls 12.5%) of patients; 80% of recombinant factor VIIa patients requiring postoperative ECMO had interventions for circuit thrombosis (controls 31.25%); 4.76% of rVIIa recipients required reexploration for intractable bleeding (controls 1.39%).ConclusionsThis study added to understanding regarding the use of recombinant factor VIIa in pediatric cardiac surgery and reported increased thrombotic complications, especially for children who progress to ECMO. Prospective studies to better understand the pathophysiology of coagulopathy and hemorrhage in pediatric cardiac surgery and the role of hemostatic agents, such as rVIIa, are required.  相似文献   

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