Consumption Coagulopathy

Updated: Sep 30, 2019
  • Author: Vikramjit S Kanwar, MBBS, MBA, MRCP(UK), FAAP; Chief Editor: Vikramjit S Kanwar, MBBS, MBA, MRCP(UK), FAAP  more...
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Overview

Practice Essentials

Consumption coagulopathy, better known as disseminated intravascular coagulation (DIC), is characterized by abnormally increased activation of procoagulant pathways. This results in intravascular fibrin deposition and decreased levels of hemostatic components, including platelets, fibrinogen, and other clotting factors. Although chronic DIC can be asymptomatic, acute DIC results in bleeding and intravascular thrombus formation that can lead to tissue hypoxia, multiorgan dysfunction, and death. [1, 2]  The most important concept in DIC is that it is a secondary manifestation of an underlying disorder.

Signs of disseminated intravascular coagulation

The clinical picture in DIC is commonly one of bleeding with signs of shock out of proportion to the amount of blood loss, with poor perfusion, cold extremities, and poor tone in the neonate.

Bleeding may range in severity from petechiae, purpura, subconjunctival or mucosal hemorrhages and extravasation from past venipuncture or surgical sites, to severe life-threatening hemorrhage.

Workup in disseminated intravascular coagulation

No single test or combination of tests is adequate to diagnose DIC. [3] Perform screening tests in all patients, such as platelet count, prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time, and assessment of fibrin degradation products or soluble fibrin monomers.

Thrombocytopenia is an almost universal finding, and the complete blood count (CBC) with smear review may reveal findings suggestive of DIC, such as increased platelet size, schistocytes, and helmet cells.

Because DIC is not the primary disease but a manifestation of underlying illness, diagnosing the initiating disorder is crucial.

Management of disseminated intravascular coagulation

The most important therapeutic maneuver in DIC is treating the initiating disorder. Without this, supportive measures ultimately fail. Shock is a frequent underlying factor, and important supportive measures include ventilatory support, volume support, and pressor support, as well as close monitoring of neurologic and renal function. Dialysis may be needed.

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Pathophysiology

The excess production of thrombin is central to the process of DIC. In addition to the conversion of fibrinogen to fibrin, thrombin has numerous other effects relative to the coagulation cascade. Thrombin contributes to the activation of factors V, VIII, and XIII (fibrin-stabilizing factor) and has an activating effect on platelets. Modulation of anticoagulant molecules also occurs by means of a thrombin-dependent mechanism. This mechanism includes generation of activated protein C and protein S and the activation of tissue-type plasminogen activator (tPA), with subsequent inhibition of activated factors V and VIII, plasminogen activator inhibitor-1 (PAI-1), and thrombin-activated fibrinolysis inhibitor (TAFI).

Tissue factor–dependent (extrinsic) pathway

Tissue factor (TF), or thromboplastin, is the primary activating moiety for the extrinsic pathway of coagulation. TF binds to factor VII and converts factor VII to factor VIIa. The resultant dimeric TF–factor VIIa complex then activates factors X and IX. TF is also a principal activator of factor IX. TF is expressed by cells of the subendothelium (smooth muscle cells, fibroblasts), whereas various stimuli may induce leukocytes and endothelial cells to express TF.

TF has a prominent role in the pathophysiology of DIC. [4] Production of TF is increased in infection. Endotoxin, tumor necrosis factor (TNF), interleukin-1 (IL-1), and other inflammatory mediators induce expression of TF in endothelial cells and monocytes, where only small amounts are normally expressed. Some evidence suggests that in sepsis-related DIC, TF and procoagulant-laden microparticles (MPs) are present in the circulation. [5]

Excessive release of TF is the primary mechanism involved in DIC resulting from trauma, especially head injury, and obstetric complications, which include intrauterine fetal demise, amniotic fluid embolism, and placental abruption. In trauma, tissue damage leads to release of TF and other tissue thromboplastins. Because of the rich TF content of brain tissue, massive head injuries are often complicated by DIC, and recent data suggest that brain trauma releases procoagulant-rich microparticles. [6]

Many malignancies are associated with cancer-derived procoagulants (CDP). TF is expressed on subcellular membrane vesicles termed plasma MPs. The procoagulant activity of these MPs was increased in patients in overt DIC with an underlying malignancy. [7] In acute promyelocytic leukemia (APL), CDP and TF are contained in multiple granules in the myeloblasts, which are responsible for the DIC commonly seen when chemotherapy results in leukemic cell lysis. [8] The use of differentiating agents in APL has significantly reduced this complication.

An uncommon source of thromboplastic activity is snake venom; some snake bites can lead to direct activation of factor X and hemorrhagic DIC.

Endothelial cells, monocytes and other cells produce and secrete a natural inhibitor of TF (ie, TF pathway inhibitor [TFPI]). The balance between TF and TFPI determines overall activity of the extrinsic pathway. Levels of TFPI are increased early in DIC; however, when overt DIC develops, the TF-to-TFPI ratio increases to the point that the extrinsic pathway is activated. Resolution of DIC results in a normalization of this ratio. [9]

Intrinsic (contact) pathway

Although the TF pathway is believed to be primary in the initiation of DIC, several instances in which the intrinsic pathway contributes to the pathophysiology of DIC are observed. Factor XII activation occurs in response to endotoxin, antigen-antibody complexes, fatty acids from fat embolism, burns, and extracorporeal circulation. In addition, factor XIIa leads to the activation of the complement system and generation of bradykinin. Increased levels of bradykinin may be responsible for hypotension observed in many forms of DIC.

Miscellaneous

Hypotensive shock and DIC may accompany severe hemolytic transfusion reactions. Immune complexes that form in such instances activate complement and initiate coagulation. Exposure of lipids normally residing on the internal surface of the erythrocyte plasma membrane may be involved in activation of the coagulation cascade.

Anticoagulant proteins C and S and antithrombin III also play a role in DIC. Congenital homozygous deficiencies of proteins C and S may result in neonatal DIC. Low levels of antithrombin III are noted during DIC, and infusion of antithrombin III concentrate may aid in the recovery from DIC.

The Ashwell receptor is a transmembrane glycoprotein on the vascular cell surface of hepatocytes. This receptor is involved in the clearance of prothrombotic factors and may mitigate sepsis-related DIC. [10]

Fibrinolysis

Unregulated generation of thrombin and deposition of fibrin provide a strong stimulus to the fibrinolytic system. Whether fibrinolysis is a primary or secondary event is uncertain, but most believe that the fibrinolytic system is activated in response to the initiation of coagulation. In response to thrombin generation and endothelial injury, tPA is released from the endothelium. The continued activity of the fibrinolytic system contributes to the consumption of coagulation factors and to development of the hemorrhagic diathesis.

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Epidemiology

Frequency

United States

The incidence of DIC is unknown.

International

The incidence of DIC among hospitalized children in Turkey is around 1%. [11] A Japanese study, by Araki et al, of newborns admitted to neonatal intensive care units found that 2.4% were diagnosed with DIC, with the incidence of the condition being 9.8% in extremely low birth weight infants. [12]

Mortality/Morbidity

The DIC mortality rate varies depending on the underlying disorder and on the availability of supportive care. The overall mortality rate for children with sepsis-related DIC is 13-40%. In developing countries, this rate can exceed 90%.

A Korean study, by Sohn et al, found that among patients with primary postpartum hemorrhage presenting to an emergency department, 22.4% of whom had overt DIC, the rate of major adverse events in women with DIC versus those without it were 96.5% and 44.4%, respectively. [13]

In the aforementioned study by Araki et al, among newborns admitted to neonatal intensive care units, those with DIC had a mortality rate at discharge of 14.1%, compared with 1.2% in those without DIC. [12]

Race

No predilection for any race is known.

Sex

No predilection for either sex is known.

Age

DIC occurs at any age.

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Prognosis

A study by Slatnick et al found that in pediatric patients with suspected sepsis, those with overt DIC (International Society of Thrombosis and Hemostasis criteria score of 5 or above) had a greater likelihood of vasopressor use (odds ratio [OR] = 2.52) and 1-year mortality (OR = 2.88) than did patients without the overt condition. Moreover, the average length of stay in the hospital and pediatric intensive care unit was longer for the patients with overt DIC (18 vs 10 days and 7.5 vs 4 days, respectively). [14]

A report by Liras et al found that evidence of acute traumatic coagulopathy existed in approximately 60% of severely injured pediatric study patients on hospital arrival. Moreover, the mortality rate for children and adolescents with coagulopathic head injuries was 31%, compared with 10% for pediatric head-injury patients without coagulopathy. [15]

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