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Disseminated Intravascular Coaggulation and Purpura Fulminans. Robert Lampman, MD Morning Report May 2010. The next series of 3 slides have figures that have been shamelessly borrowed/modified from a presentation by Dr Elizabeth Bengston of Dartmouth Medical School.
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Disseminated Intravascular Coaggulation and PurpuraFulminans Robert Lampman, MD Morning Report May 2010
The next series of 3 slides have figures that have been shamelessly borrowed/modified from a presentation by Dr Elizabeth Bengston of Dartmouth Medical School.
Kumar: Robbins and Cotran Pathologic Basis of Disease, Professional Edition , 8th ed.
DIC – The Pathophysiology • Paroxysmal or insidious onset of widespread fibrin thrombi in the microcirculation • Widespread thrombi formation results in platelet and coagulation protein consumption • Simultaneous activation of fibrinolytic mechanism • Thrombotic disorder -> Bleeding catastrophe Kumar: Robbins and Cotran Pathologic Basis of Disease, Professional Edition , 8th ed.
DIC - 2 Pathways of Activation • 1. Tissue Factor or thromboplastic substance release into circulation. • obstetrics, malignancy, trauma, surgery, tissue necrosis • 2. Endothelial Injury - collagen exposure • endotoxin, bacteria, virus, burns
Purpura Fulminans • “Purpura fulminans is characterized by the rapid progression of ecchymotic skin lesions, especially of the extremities, that may progress to gangrene, ultimately resulting in amputation.” • Rare and more often seen in children • Post infection: scarlett fever, varicella, URI (meningococcus) • Appears 0-90 days post infection Hoffman: Hematology: Basic Principles and Practice, 5th ed.
Purpura Fulminans - Pathophysiology • Most Accepted Explanation: Deficiency of Anticoaggulants • Acquired Protein S def, Anti-Protein S Antibody • Low levels Activated Protein C -> low levels Protein C, protein S, and antithrombin (thrombomodulin-PrC pathway) Hoffman: Hematology: Basic Principles and Practice, 5th ed.
DIC - Treatment • FFP to keep the INR <2 • Cryoprecipitate to keep the Fibrinogen level >100 • ATIII Concentrates - KyberSept trial, a double-blind placebo-controlled trial of the use of ATIII concentrates in 2300 adults with sepsis, found no difference in mortality at day 28 after diagnosis. • Heparin low dose – Controversial. Ad hoc retrospective analysis shows benefit equal to “treatment” arms of study.
DIC / Purpura Fulminans - Treatment • APC concentrates – Very Controversial. • phase II trial: protein C concentrate for Tx of sepsis and purpura fulminans in children. Dose-dependent activation of protein C and normalization of coagulation imbalances. Not powered to detect mortality differences, none seen. • PROWESS vs ADDRESS trials for sepsis • Summary: 24hrs onset, multiorgan failure (SOFA scale etc), APACHE II >25
References • Toussaint S, Gerlach H. Activated protein C for sepsis. N Engl J Med. 2009 Dec 31;361(27):2646-52. • Hoffman: Hematology: Basic Principles and Practice, 5th ed. • Kumar: Robbins and Cotran Pathologic Basis of Disease, Professional Edition , 8th ed. • Osler W. Principles and Practice of Medicine. 4th Edition. D. Aplleton and Company. New York. 1901. • Dr Elizabeth Bengston. Assistance Professor of Medicine, Hematology/Oncology. Dartmouth Medical School. Medical Student Lectures 2005. • Cornet AD, Smit EG, Beishuizen A, Groeneveld AB. The role of heparin and allied compounds in the treatment of sepsis. Thromb Haemost. 2007 Sep;98(3):579-86.