Seminars in cardiothoracic and vascular anesthesia
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Cardiopulmonary bypass has unpredictably deleterious effects on platelet function. Patients with cardiovascular disease have treatments aimed at reducing platelet aggregation and are at risk of excessive bleeding during surgery. Transfusion of blood products, particularly platelets, probably causes increased morbidity and mortality. ⋯ Point-of-care (POC) testing of platelet function should facilitate the clinical management of bleeding patients by rationalizing platelet transfusion and avoiding unnecessary transfusion. Furthermore, POC platelet function could alert the clinician to risks of excessive platelet activation and measure the efficacy of antiplatelet therapy. This article outlines some of the POC platelet function monitors available as well as their potential applications.
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Semin Cardiothorac Vasc Anesth · Dec 2007
ReviewImpact of perioperative transesophageal echocardiography in aortic valve replacement.
Intraoperative transesophageal echocardiography (TEE) is currently being used routinely during aortic valve replacement (AVR). TEE provides information that can lead to modifications of anesthetic and surgical care that leads to improved outcome. Numerous studies have shown that modifications in therapy occur from 10% to more than 40% of cases. ⋯ TEE can guide and modify the placement of various bypass cannulae. After bypass, TEE verifies the surgical result, rules out left and right ventricular outflow tract obstruction, and assures stable hemodynamics. Although current guidelines state that aortic valve surgery is a class IIa indication for TEE use, the authors' experience suggests that TEE should be routinely used in AVR.
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Unfractionated heparin and protamine have been integral to cardiopulmonary bypass since cardiac surgery was first undertaken. These drugs are inexpensive and well understood but are contraindicated in some individuals, and resistance to heparin can be problematic in others. ⋯ At present, direct thrombin inhibitors may offer the best available alternative to heparin in cardiac surgery, particularly the short-acting bivalirudin, but this class of anticoagulants is relatively expensive and has no reversal agent. Balanced anticoagulation using combinations of drugs that act at different stages in the coagulation system may improve the management of coagulation in cardiac surgery, but careful investigation of this concept is needed.
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Semin Cardiothorac Vasc Anesth · Dec 2007
ReviewProgrammatic blood conservation in cardiac surgery.
Despite efforts to reduce blood transfusion rates in cardiac surgery over the past 40 years, cardiac surgery still consumes 10% to 20% of the blood transfused in the United States. This large demand has not only placed a significant pressure on the national blood supply, resulting in frequent shortages, but also has lead to many technical and pharmacological advances in blood conservation strategies in recent years. ⋯ Early preoperative planning and a coordinated perioperative plan allow the appropriate use of blood conservation modalities to ensure that their benefits span the entire perioperative period. This article describes some of the modalities currently used in patients undergoing cardiac surgery.
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Semin Cardiothorac Vasc Anesth · Dec 2007
Vascular injury and thrombotic potential: a note of caution about recombinant factor VIIa.
Postoperative hemorrhage following cardiac surgery increases morbidity, mortality, and costs. Several case reports have described the successful use of recombinant factor VIIa to decrease or stop bleeding in patients undergoing cardiac surgery. ⋯ However, there have also been many reports of thrombotic complications after recombinant factor VIIa administration. Randomized clinical trials and further laboratory studies should help better clarify the efficacy, safety, cost-effectiveness, and optimal dosing of recombinant factor VIIa in the cardiac surgical setting.