Seminars in thrombosis and hemostasis
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Semin. Thromb. Hemost. · Feb 2015
ReviewHemostasis and thrombosis in continuous renal replacement treatment.
During continuous renal replacement therapy, the delicate equilibrium of hemostasis is disturbed. Owing to a complex interaction of critical illness, uremia, use of an extracorporeal circuit and anticoagulation, patients exhibit both hypercoagulability and an increased risk of bleeding. Contact of blood with foreign material initiates coagulation by triggering the contact activation coagulation pathway, the tissue factor-factor VIIa pathway and activation of platelets and monocytes, which adhere to the membrane. ⋯ Its interference with anticoagulation is therefore unreliable during critical illness. Citrate provides regional anticoagulation and increases biocompatibility. It is better tolerated than heparin and confers less bleeding, less transfusion, and longer circuit life.
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Semin. Thromb. Hemost. · Feb 2015
ReviewHeparin-induced thrombocytopenia in critically ill patients.
Many critically ill patients receive heparin, either before intensive care unit (ICU) admission (e.g., postcardiac surgery), for prophylaxis/treatment of thrombosis, for hemodialysis/filtration, or even incidentally (e.g., flushing of intravascular catheters), and are therefore at risk for developing immune heparin-induced thrombocytopenia (HIT), a prothrombotic drug reaction caused by platelet-activating antiplatelet factor 4 (PF4)/heparin antibodies. However, HIT explains at most 1 in 100 thrombocytopenic ICU patients (HIT frequency 0.3-0.5% vs. 30-50% background frequency of ICU-associated thrombocytopenia), and most patients who form anti-PF4/heparin antibodies do not develop HIT; hence, HIT overdiagnosis often occurs. This review discusses HIT-related issues relevant to ICU patients, including how to (1) distinguish HIT both clinically and serologically from non-HIT-related thrombocytopenia; (2) recognize HIT-mimicking disorders, such as the acute disseminated intravascular coagulation (DIC)/liver necrosis-limb necrosis syndrome; (3) prevent HIT in the ICU through use of low-molecular-weight heparin; and (4) treat HIT, including awareness of "PTT confounding" when anticoagulating patients with DIC.
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Semin. Thromb. Hemost. · Feb 2015
Randomized Controlled TrialProfound endothelial damage predicts impending organ failure and death in sepsis.
Endothelial damage contributes to organ failure and mortality in sepsis, but the extent of the contribution remains poorly quantified. Here, we examine the association between biomarkers of superficial and profound endothelial damage (syndecan-1 and soluble thrombomodulin [sTM], respectively), organ failure, and death in sepsis. The data from a clinical trial, including critically ill patients predominantly suffering sepsis (Clinicaltrials.gov: NCT00271752) were studied. ⋯ Profound damage to the endothelium independently predicts risk of multiple organ failure and death in septic patients. Our findings also suggest that the detrimental effect of profound endothelial damage on risk of death operates via mechanisms other than causing organ failures per se. Therefore, damage to the endothelium appears centrally involved in the pathogenesis of death in sepsis and could be a target for intervention.
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Cardiac surgery with cardiopulmonary bypass determines a serious imbalance of the hemostatic system. The clinical pattern is multifactorial, involving patient-related, drug-related, and surgery-related factors. As a result, the patient is prone to both hemorrhagic and thrombotic complications. ⋯ Thromboembolic complications are the other side of the coin, and their prevention is still a matter of debate. Consumption of natural anticoagulants and endothelial disturbance are important mechanisms underlying this condition. Strategies to limit antithrombin (AT) consumption or to correct low postoperative levels of AT are still a matter of discussion.
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Semin. Thromb. Hemost. · Feb 2015
Observational StudyFibrinogen level deteriorates before other routine coagulation parameters and massive transfusion in the early phase of severe trauma: a retrospective observational study.
In trauma, hemostatic functions should be maintained appropriately to prevent massive bleeding. This study elucidated the time-dependent changes in platelet count and coagulation variables, and the effects of disseminated intravascular coagulation (DIC) on these changes during the early phase of trauma. Trauma patients with an injury severity score ≥16 were enrolled. ⋯ Routine coagulation parameters reached their critical levels earlier in DIC patients than patients without DIC. Massive transfusion was performed more frequently in DIC patients, who met the criteria earlier. During the early phase of trauma, fibrinogen levels deteriorate earlier than other routine coagulation parameters, especially in DIC patients.