1/13. Physician preferences for perioperative anticoagulation in patients with a mechanical heart valve who are undergoing elective noncardiac surgery.STUDY OBJECTIVE: To determine physicians' anticoagulation preferences in patients with a mechanical heart valve who are undergoing elective surgery, and to determine the effect of different risks of thromboembolism (TE) and postoperative bleeding on anticoagulation preferences. DESIGN: Mail survey of physicians who prescribe anticoagulant therapy. methods AND RESULTS: physicians were asked to provide anticoagulation preferences in four clinical scenarios of patients with a mechanical heart valve who are undergoing elective surgery. physicians were asked to select from three preoperative anticoagulation options (two aggressive, one less aggressive) and four postoperative anticoagulation options (two aggressive, two less aggressive). IV heparin was the most frequently selected anticoagulation option. Depending on the scenario, it was preferred by 39 to 79% of respondents for preoperative anticoagulation therapy, and by 44 to 84% of respondents for postoperative anticoagulant therapy. The risk of TE had a strong influence on anticoagulation preferences: more respondents preferred aggressive anticoagulant management in high-risk compared with low-risk TE scenarios (p < 0.001). Anticoagulation preferences were not influenced by the risk of bleeding: the proportion of respondents who preferred aggressive anticoagulant management did not differ in high-risk and low-risk bleeding scenarios (p > 0.05). Of respondents who preferred IV heparin for postoperative anticoagulation therapy, the risk of bleeding influenced the timing of heparin initiation: fewer respondents preferred early heparin initiation (within 12 h after surgery) in high-risk compared with low-risk bleeding scenarios (p < 0.01). CONCLUSIONS: (1) Preoperative and postoperative IV heparin were the most frequently selected anticoagulation options. (2) The risk of TE, but not the risk of bleeding, influenced the aggressiveness of anticoagulant management. (3) If IV heparin was selected, the risk of bleeding influenced the timing of heparin initiation.- - - - - - - - - - ranking = 1keywords = physician (Clic here for more details about this article) |
2/13. Delayed-onset heparin-induced thrombocytopenia.BACKGROUND: heparin-induced thrombocytopenia presents 5 to 12 days after heparin exposure, with or without arterial or venous thromboemboli. Delayed recognition and treatment of heparin-induced thrombocytopenia contribute to poor patient outcomes. OBJECTIVE: To describe and increase awareness of a clinical scenario in which the onset or manifestations of heparin-induced thrombocytopenia are delayed. DESIGN: Retrospective case series. SETTING: Three large urban hospitals (with active cardiovascular surgery programs). patients: 14 patients seen over a 3-year period in whom heparin-induced thrombocytopenia became apparent on delayed presentation with thromboembolic complications. MEASUREMENTS: Platelet counts, onset of objectively determined thromboembolism, results of heparin-induced platelet factor 4 antibody tests, and outcomes. RESULTS: patients went home after hospitalizations that had included heparin exposure--in most cases, with no thrombocytopenia recognized--only to return to the hospital (median, day 14) with thromboembolic complications. Thromboemboli were venous (12 patients, 7 with pulmonary emboli) or arterial (4 patients) or both. Platelet counts were mildly decreased in all but 2 patients on second presentation. On readmission, 11 patients received therapeutic heparin, which worsened the patients' clinical condition and, in all 11 cases, decreased the platelet count (mean at readmission, 143 x 10(9) cells/L; mean nadir after heparin re-exposure, 39 x 10(9) cells/L). Results of serologic tests for heparin-induced antibodies were positive in all patients. Subsequent treatments included alternative anticoagulants (11 patients), thrombolytic drugs (3 patients), inferior vena cava filters (3 patients) and, eventually, warfarin (11 patients). Three patients died. CONCLUSIONS: Delayed-onset heparin-induced thrombocytopenia is increasingly being recognized. To avoid disastrous outcomes, physicians must consider heparin-induced thrombocytopenia whenever a recently hospitalized patient returns with thromboembolism; therapy with alternative anticoagulants, not heparin, should be initiated.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
3/13. Anticoagulation during pregnancy.Anticoagulation of a pregnant woman is a complex issue for both the treating physician and the patient. In patients with mechanical prosthetic valves, long-term anticoagulation is mandatory to prevent thromboembolic complications; and in those with thrombophilic disorders and history of thromboembolism, anticoagulation is strongly indicated. With an increase in the number of patients with prosthetic heart valves, as well as the increase in maternal age, the issue of anticoagulation has become a very important one. Despite the widespread use of warfarin and unfractionated heparin during pregnancy, the optimal use of anticoagulants during pregnancy remains controversial because of a lack of appropriate prospective randomized clinical trials. In fact, even retrospective data on heparin provide miserably inadequate information for those making a decision on the correct dosing regimen. More recently, low molecular weight heparin has been proposed as a safer method of anticoagulation. This review summarizes current data and recommendations on anticoagulation during pregnancy.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
4/13. A silent killer--often preventable.Deep vein thrombosis and its potentially fatal complication, PE, accounts for more than 250,000 hospitalizations annually in the united states. pulmonary embolism is the most serious complication and has a 3-month mortality of 17%. Two million people each year are affected by VTE, and the prevalence is rising because of the aging population. Deep vein thrombosis and its potential complication, PE, is preventable. However, there still is widespread failure to screen, diagnose, and initiate prophylactic therapy in patients at risk. This failure can be corrected by development of a heightened awareness of risk factors among emergency department physicians and nurses and by similar personnel caring for bedridden hospitalized patients. A recent landmark study Prophylaxis in Medical patients With enoxaparin Study (MEDENOX) revealed the risk factors of VTE in order of frequency: (1) previous VTE, (2) acute infectious disease, (3) cancer, (4) age greater than 75 years, and (5) chronic respiratory disease. This study confirmed the effectiveness of a LMWH, enoxaparin, in the prevention of VTE.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
5/13. heparin-induced thrombocytopenia in the emergency department.We describe 3 patients who presented to the emergency department (ED) with stroke, deep venous thrombosis, or pulmonary embolism and renal failure after undergoing cardiac surgery 7 to 17 days earlier. Their onset of thrombosis after previous heparin exposure was temporally plausible for complications of heparin-induced thrombocytopenia, an immune-mediated thrombotic disorder triggered by heparin. The patients had normal platelet counts at presentation, yet each had circulating heparin-induced thrombocytopenia antibodies that were ultimately confirmed. Two patients had heparin reexposure in the ED, 1 of whom developed thrombocytopenia with new thrombosis and died. Alternative parenteral anticoagulation prevented further thrombosis in 2 patients. Because heparin use can be catastrophic in patients with heparin-induced thrombocytopenia, physicians should be vigilant in suspecting heparin-induced thrombocytopenia in patients with thrombosis after recent hospitalization or heparin exposure. Alternative anticoagulants are available for these at-risk patients.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
6/13. Recurrent embolism in the course of marantic endocarditis.Marantic or nonbacterial thrombotic endocarditis (NBTE) associated with systemic embolism is usually a complication of advanced or terminal malignancies. We report on the case of a 46-year-old woman in whom nonbacterial thrombotic endocarditis (NBTE)-related cerebral embolism was the first clinical sign of ovarian neoplasm, which was diagnosed after cardiac surgery. Marantic endocarditis should alert the physician to make every effort to diagnose the possible background of this clinical phenomenon. Early identification of NBTE, treatment of the underlying disease, and the associated coagulopathy could possibly prevent cardiac surgery.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
7/13. subclavian vein thrombosis following IVF and ovarian hyperstimulation: a case report.Thromboembolic phenomena are a serious consequence of assisted reproductive technology. We present a case of upper extremity deep vein thrombosis (DVT) at 7 weeks gestation following ovarian hyperstimulation syndrome (OHSS) and IVF. Three weeks after recovering from OHSS, the patient presented with left neck pain and swelling. Ultrasound revealed a thrombus in the left jugular vein and left subclavian vein. Low molecular weight heparin (LMWH) was initiated with symptom resolution within 1 week. The patient remained on LWMH throughout her pregnancy and delivered at term. A literature review showed 97 published cases of thromboembolism following ovulation induction. A majority of these cases was associated with OHSS and pregnancy and the site of involvement was predominantly in the upper extremity and neck. infertility physicians and obstetricians should be aware of this complication and keep in mind that it may occur weeks after resolution of OHSS symptoms.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
8/13. Systemic embolization following thrombolytic therapy for acute myocardial infarction.We describe a patient with acute inferior myocardial infarction who developed a "saddle" aortic embolus during streptokinase infusion. Three months previously, this patient had sustained an anterior infarction, and an apical aneurysm was found. This patient's embolus had most probably originated from a left ventricular mural thrombus that had been dislodged by streptokinase. As fibrinolytic treatment is gaining wide acceptance, physicians should be aware of this rare, but possible, complication.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
9/13. Thromboembolic and infectious complications of total artificial heart implantation.Thromboembolic and infectious events were found to be major complications of long-term total artificial heart implantation in two patients. Similar complications have been reported in other patients, as well as in animal studies. The thromboembolic events and the infectious complications appear to be interrelated. On the one hand, thrombi located on the valves and at the vascular anastomoses of the artificial heart were found to be infected at autopsy; such infections are known to exacerbate formation of thromboemboli. On the other hand, the generation of microthrombi may have contributed to the RES blockade seen in our patients. We hypothesize that this RES blockade led to a progressive decrease in lymphoid system function and impaired the patients' capacity to clear microorganisms from the circulation. These phenomena arose, in part, from the design of the artificial heart and were exacerbated by associated therapy, such as blood transfusions. Our data suggest several measures that might be taken in order to reduce the severity of both the thrombogenic and infectious complications. Improved anticoagulation regimens, which increase the ability of the physician to maintain the proper balance between thrombotic and hemorrhagic potential, are needed. This may require not only improved methods of monitoring anticoagulation and predicting changes in the effectiveness of various agents as other events supervene, but also new anticoagulant and antithrombotic drugs, for example, low molecular weight heparins and prostacyclin derivatives. It is also clear that the design of the artificial heart should be modified in order to improve fluid dynamics so that they will approximate as closely as possible those of the natural heart. This includes redesigning the mounting of the valves to eliminate crevices and discontinuities that allow stagnant flow and predispose to thrombus formation as well as imposing a dP/dt that minimizes shear-related hemolysis, thereby minimizing the need for blood transfusions. Prevention of infections presents a more difficult problem. Transcutaneous lines (regardless of their use) are an obvious route for infection, and attention should be given to minimizing the number and length of use of monitoring lines. However, until a totally implantable drive system is available, the drive lines will remain a potential avenue for the introduction of infections. The risk may be minimized by rigorous attention to care of the exit sites and by improved designs that will provide a better mechanical barrier by, for example, enhancing epithelial ingrowth into the materials of the drive line.(ABSTRACT TRUNCATED AT 250 WORDS)- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
10/13. Arterial thromboembolism and associated antithrombin iii deficiency.A patient with antithrombin III (ATT) deficiency after arterial embolism manifested an increasing requirement for heparin to adjust a partial thromboplastin time. This was corrected by dramatically increasing doses of heparin and by conversion to warfarin sodium. "heparin-resistance" should direct the physician to examine antithrombin III levels, and ATT levels should be determined as a baseline before anticoagulation therapy.- - - - - - - - - - ranking = 0.5keywords = physician (Clic here for more details about this article) |
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