Finding a common definition of heparin resistance in adult cardiac surgery: communication from the ISTH SSC subcommittee on perioperative and critical care thrombosis and hemostasis.

Ensuring adequate anticoagulation for patients requiring cardiac surgery and cardiopulmonary bypass (CPB) is important due to the adverse consequences of inadequate anticoagulation with respect to bleeding and thrombosis. When target anticoagulation is not achieved with typical doses, the term heparin resistance is routinely used despite the lack of uniform diagnostic criteria. Prior reports and guidance documents that define heparin resistance in patients requiring CPB and guidance documents remain variable based on the lack of standardized criteria.

Optimizing management of replacement fluids for therapeutic plasma exchange: Use of an automated mathematical model to predict post-procedure fibrinogen and antithrombin levels in high-risk patients.

Background: Therapeutic plasma exchange (TPE) utilizes an extracorporeal circuit to remove pathologic proteins causing serious illness. When processing a patient's entire blood volume through an extracorporeal circuit, proteins responsible for maintaining hemostatic system homeostasis can reach critically low levels if replacement fluid types and volumes are not carefully titrated, which may increase complications.

Methods: The charts from 27 patients undergoing 46 TPE procedures were reviewed to evaluate the accuracy of our predictive mathematical model, utilizing the following patient information: weight, hematocrit, pre- and post-TPE factor levels (fibrinogen, n = 46, and antithrombin, n = 23), process volume and volumes of fluids (eg, plasma, albumin, and normal saline) administered during TPE and adverse events during and after TPE.

Factors Associated With Mortality and Response to Extracorporeal Photopheresis in Lung Allograft Recipients With Bronchiolitis Obliterans Syndrome.

Background: This study was designed to identify factors associated with clinical response to extracorporeal photopheresis (ECP) and mortality after ECP in lung allograft recipients with bronchiolitis obliterans.

Methods: Forced expiratory volume in 1 second (FEV1) values obtained 6 months before (baseline) and 6 months after initiation of ECP were used to plot the linear relationship between FEV1 versus time before and after ECP. Response to ECP was assigned when a positive integer was derived after subtracting the baseline rate of decline from the rate of decline 6 months after ECP.

Acute graft-versus-host disease following lung transplantation in a patient with a novel mutation.

Familial pulmonary fibrosis is associated with loss-of-function mutations in telomerase reverse transcriptase () and short telomeres. Interstitial lung diseases have become the leading indication for lung transplantation in the USA, and recent data indicate that pathogenic mutations in telomerase may cause unfavourable outcomes following lung transplantation. Although a rare occurrence, solid organ transplant recipients who develop acute graft-versus-host disease (GVHD) have very poor survival.

Coronary artery bypass grafting in 2 thrombophilic patients with protein s deficiency.

In this report, we review 2 cases of coronary revascularization in patients with a diagnosis of coronary artery disease and preoperative protein S deficiency, an established hypercoagulable condition. In an attempt to normalize protein S levels, fresh frozen plasma was used as the priming fluid for the cardiopulmonary bypass circuit before the initiation of extracorporeal circulation. On the basis of a low risk of bleeding and the theoretical risk of thrombosis, neither patient received intraoperative antifibrinolytic treatment nor did they develop perioperative thrombotic complications.

The occurrence of antibodies to heparin-platelet factor 4 in cardiac and thoracic surgical patients receiving desirudin or heparin for postoperative venous thrombosis prophylaxis.

Introduction: This randomized, exploratory study compared the incidence of heparin-dependent antibodies associated with subcutaneous (SC) desirudin or heparin given for deep-vein thrombosis prophylaxis following cardiac and thoracic surgery.

Materials And Methods: Adult patients scheduled for elective cardiac or thoracic surgery received desirudin 15 mg SC twice daily or unfractionated heparin 5000 units SC thrice daily. Duration of thrombosis prophylaxis was determined by the treating physician.

2011 update to the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists blood conservation clinical practice guidelines.

Background: Practice guidelines reflect published literature. Because of the ever changing literature base, it is necessary to update and revise guideline recommendations from time to time. The Society of Thoracic Surgeons recommends review and possible update of previously published guidelines at least every three years.

The efficacy of photopheresis for bronchiolitis obliterans syndrome after lung transplantation.

Background: Extracorporeal photopheresis (ECP) has been used to treat acute and chronic rejection after solid organ transplantation. However, data supporting the use of ECP for bronchiolitis obliterans syndrome (BOS) after lung transplantation are limited.

Methods: We retrospectively analyzed the efficacy and safety of ECP for progressive BOS at our institution.

Use of activated recombinant factor VII for severe coagulopathy post ventricular assist device or orthotopic heart transplant.

Background: Ventricular assist devices(VAD) implantation/removal is a complex surgical procedure with perioperative bleeding complications occurring in nearly half of the cases. Recombinant activated factor VII (rFVIIa) has been used off-label to control severe hemorrhage in surgery and trauma. We report here our experience with rFVIIa as a rescue therapy to achieve hemostasis in patients undergoing orthotopic heart transplant (OHT) and/or VAD implantation.

Transfusion algorithms and how they apply to blood conservation: the high-risk cardiac surgical patient.

Considerable blood product support is administered to the cardiac surgery population. Due to the multifactorial etiology of bleeding in the cardiac bypass patient, blood products frequently and empirically are infused to correct bleeding, with varying success. Several studies have demonstrated the benefit of algorithm-guided transfusion in reducing blood loss, transfusion exposure, or rate of surgical re-exploration for bleeding.

Transfusion risks and transfusion-related pro-inflammatory responses.

Despite improvements in blood screening and administration techniques, serious adverse events related to transfusion continue to occur, albeit at a much lower incidence. In addition to the development and implementation of new screening and blood purification/modification techniques and implementation of an optimal blood management program, the incidence and consequences of transfusion reactions can be reduced by a basic understanding of transfusion-related complications. Although acute hemolytic transfusion reactions, transfusion-associated anaphylaxis and sepsis, and transfusion-associated acute lung injury occur infrequently, diligence in administration of blood and monitoring for development of respective signs/symptoms can minimize the severity of these potentially life-threatening complications.

Preoperative use of enoxaparin increases the risk of postoperative bleeding and re-exploration in cardiac surgery patients.

Objective: The purpose of this study was to investigate if the preoperative use of new platelet inhibitors and low-molecular-weight heparins may contribute to bleeding after cardiac surgery.

Design: Retrospective data review.

Setting: University teaching hospital.

A phase III, double-blind, placebo-controlled, multicenter study on the efficacy of recombinant human antithrombin in heparin-resistant patients scheduled to undergo cardiac surgery necessitating cardiopulmonary bypass.

Background: The study evaluated the efficacy of recombinant human antithrombin (rhAT) for restoring heparin responsiveness in heparin resistant patients undergoing cardiac surgery.

Methods: This was a multicenter, randomized, double-blind, placebo-controlled study in heparin-resistant patients undergoing cardiac surgery with cardiopulmonary bypass. Heparin resistance was diagnosed when the activated clotting time was less than 480 s after 400 U/kg heparin.

Guidelines and alternatives for neuraxial anesthesia and venous thromboembolism prophylaxis in major orthopedic surgery.

Neuraxial anesthesia during major orthopedic surgery, combined with venous thromboembolism prophylaxis, is generally safe and well tolerated, with potential benefits over general anesthesia. The risk of spinal/epidural hematoma, a rare but very serious complication, can be minimized by careful patient selection and attention to anesthetic technique. This risk is further reduced with the use of peripheral nerve blocks in place of neuraxial anesthesia.

The influence of crystalloid and colloid replacement solutions in acute normovolemic hemodilution: a preliminary survey of hemostatic markers.

Acute normovolemic hemodilution (ANH), in which blood for autologous use is collected immediately before the onset of surgical blood loss, is a recommended autologous blood procurement technique for blood conservation. Both crystalloid and colloid replacement fluids have been used to maintain normovolemia during ANH, but few data are available to justify the use of a particular replacement fluid. Therefore, we designed a prospective, randomized study to determine if the replacement fluid choice affects various coagulation variables and perioperative blood loss.

Recombinant human transgenic antithrombin in cardiac surgery: a dose-finding study.

Background: Acquired antithrombin III (AT) deficiency may render heparin less effective during cardiac surgery and cardiopulmonary bypass (CPB). The authors examined the pharmacodynamics and optimal dose of recombinant human AT (rh-AT) needed to maintain normal AT activity during CPB, optimize the anticoagulant response to heparin, and attenuate excessive activation of the hemostatic system in patients undergoing coronary artery bypass grafting.

Methods: Thirty-six patients scheduled to undergo elective primary coronary artery bypass grafting and who had received heparin for 12 h or more before surgery were enrolled in the study.

Antithrombin III concentrate to treat heparin resistance in patients undergoing cardiac surgery.

Objective: The purpose of this report is to describe the clinical use of antithrombin III concentrate in 53 patients who were found, in the operating room before cardiopulmonary bypass, to be heparin resistant.

Method: Resistance to heparin was determined to be present when greater than 600 U/kg body weight of heparin failed to prolong the kaolin-activated clotting time to more than 600 seconds in 53 aprotinin-treated patients. Blood samples were obtained for subsequent antithrombin III activity determination.