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ASH SAP*Up-To-Date**DynaMed**
Definition/DescriptionNM/NADIC is a systemic process with the potential for causing thrombosis and hemorrhage.DIC is an acquired clinicopathological syndrome characterized by the systemic activation of coagulation that may cause organ-damaging thrombosis and/or hemorrhage due to the consumption of coagulation factors and platelets.
Underlying conditionDIC occurs in critically ill patients in the setting of a serious underlying disease.DIC does not occur in isolation. A number of underlying conditions are responsible for initiating and propagating the process.DIC develops as a complication of a large range of illnesses including infection, solid and hematological malignancies, obstetric diseases, trauma, aneurysms, and liver disease.
PathophysiologyCaused by enhanced thrombin generation because of an imbalance in the normal procoagulant and anticoagulant pathways.In DIC, the processes of coagulation and fibrinolysis become abnormally (and often massively) activated, leading to ongoing coagulation and fibrinolysis.DIC is a type of thrombotic microangiopathy. Caused by underlying clinical disorder resulting in systemic activation of coagulation with subsequent exhaustion of coagulation proteases and anticoagulant regulatory proteins, and alterations in fibrinolytic activity.
Clinical phenotype
ThromboticMany patients develop significant thrombotic complications, including peripheral ischemia and skin gangrene.Thrombosis is more likely to occur in chronic DIC, in the setting of solid tumors, but patients with acute DIC can also have thromboembolic complications.Thrombotic-type DIC typically presents with manifestations of skin infarction, microthrombosis-associated limb ischemia, or multiple organ failure.
BleedingMay result in significant bleeding, which may be the presenting feature of a hematologic malignancy such as acute promyelocytic leukemia.Common bleeding manifestations include petechiae and ecchymoses, blood oozing from wound sites, intravenous lines, catheters, and mucosal surfaces.Fibrinolytic-type DIC typically presents with oozing-type bleeding from multiple unrelated sites including mucosal site, serosal surface, venipuncture sites or intraarterial lines, surgical and traumatic wounds, or from the uterus in obstetric cases.
No one testNM/NADIC is a clinical and laboratory diagnosis, based on findings of coagulopathy and/or fibrinolysis in the appropriate setting (eg, sepsis, malignancy). No single laboratory test can accurately confirm or eliminate the diagnosisNo single laboratory test is specific for DIC. Diagnosis is based on a combination of lab markers.
TestsNumerous tests of hemostasis become abnormal, including thrombocytopenia, increased fibrin degradation products such as D-dimers, prolongation of the PT and aPTT, decreased fibrinogen concentration, and decreased protein C concentration 1.Tests include complete blood count, review of the peripheral blood smear, PT and aPTT, fibrinogen, and D-dimer.Lab abnormalities in decreasing order of frequency include reduced platelet count; elevated fibrin degradation products, PT, and aPTT; and reduced fibrinogen.
FibrinogenA significant reduction in the level of fibrinogen may indicate early or subclinical DIC even if it does not result in fibrinogen levels below laboratory reference intervals.Fibrinogen is typically low, especially in acute DIC. Importantly, patients with sepsis, malignancy, and other inflammatory conditions may have markedly increased production of fibrinogen, since fibrinogen functions as an acute phase reactant. Thus, a plasma fibrinogen level within the normal range may represent a substantial consumption (and a significant abnormality) for that patient despite being in the normal range.Fibrinogen level has high specificity to identify patients with DIC but low sensitivity to rule out DIC. Overall sensitivity of low fibrinogen level reported to be 28%, with hypofibrinogenemia occurring only in very severe cases of DIC.
Peripheral smearDIC results in a microangiopathic hemolytic anemia; the peripheral blood smear will often show schistocytes.Both DIC and other TMAs can produce microangiopathic hemolytic anemia (MAHA), characterized by schistocytes on the peripheral blood smear.Fragmented red blood cells (schistocytes) occur but finding is neither sensitive nor specific to DIC.
Scoring systemNM/NAThe International Society of Thrombosis and Haemostasis has developed a scoring system to be applied to individuals with an underlying disorder associated with DIC, which incorporates laboratory features including the PT, platelet count, fibrinogen level, and D-dimer; this scoring system has been validated but is not widely used.2Clinical prediction rules help diagnose DIC using clinical information and results from panel of widely available blood tests including platelet count, fibrin degradation products or D-dimer, fibrinogen and PT and aPTT.
Confirm diagnosisNM/NAWe consider the diagnosis of acute DIC to be established if the patient has laboratory evidence of thrombocytopenia, coagulation factor consumption (eg, prolonged PT, aPTT; low fibrinogen), and fibrinolysis (eg, increased D-dimer), as long as another etiology for these findings does not become apparent. Bleeding or thrombosis are supportive of the diagnosis if present but are not required for diagnosis.Using clinical score
Dynamic processDIC is a dynamic process requiring repeated measurements.DIC is a dynamic process… testing is often repeated serially to determine if coagulation and fibrinolysis are worsening or improving.Repeated testing is important, as the syndrome is dynamic.
Treat underlying conditionTreat the underlying condition even though this can be challenging.3DIC is a process of ongoing thrombin generation and fibrinolysis, and resolution of these abnormalities depends on elimination of the stimulus for these processes.Cornerstone of treatment is vigorous management of underlying disease.
OverviewNM/NAWe do not routinely use prophylactic administration of platelets and coagulation factors in patients who are not bleeding or who are not at high risk of bleeding, as long as the platelet count is ≥10 × 109/L. However, treatment is justified in patients who have serious bleeding, are at high risk for bleeding (eg, after surgery), or require invasive procedures. Importantly, appropriate treatment for bleeding should not be withheld for fear of “fueling the fire.”Details recommendations from several guideline organizations. Essentially the same as that detailed by Up-To-Date, namely replacement therapy is indicated only if the patient is bleeding or is at high risk for bleeding.
Platelet transfusions Platelet transfusions should generally be reserved for patients with a platelet count below 50 × 109/L, those at high risk of bleeding, or patients with worsening thrombocytopenia.4Patients with serious bleeding or need for urgent/emergent surgery and a platelet count <50,000/microL should be given platelet transfusions.

Patients with a platelet count <10 × 109/L should be given platelet transfusions due to the increased risk of spontaneous bleeding. 
ISTH Harmonization: Platelet transfusions are recommended in patients with active bleeding plus platelet count < 50 × 109/L, or high risk of bleeding plus platelets < 20 × 109/L.
Plasma transfusionsPlasma transfusions are primarily reserved for patients with an increased PT and bleeding.5Patients with serious bleeding and a significantly prolonged PT or aPTT), or a fibrinogen level <50 mg/dL and serious bleeding, should receive coagulation factor replacement. If the plasma fibrinogen level is >100 mg/dL and the PT or aPTT remains significantly elevated, we administer FFP or PF24. The goal is to reduce bleeding, not to normalize the coagulation tests.ISTH Harmonization: FFP is recommended in patients with active bleeding or requiring an invasive procedure and either prolonged PT/aPTT (> 1.5 × normal) or decreased fibrinogen (< 1.5 g/L).
Cryoprecipitate or fibrinogen concentratesCryoprecipitate or fibrinogen concentrates are indicated for patients with severe hypofibrinogenemia (fibrinogen < 100 mg/dL).6Patients with serious bleeding and a significantly prolonged PT or aPTT, or a fibrinogen level <50 mg/dL and serious bleeding, should receive coagulation factor replacement. If the plasma fibrinogen level is <100 mg/dL, we administer cryoprecipitate to increase it to >100 mg/dL.ISTH Harmonization: Cryoprecipitate or fibrinogen concentrates recommended for patients with active bleeding plus severe hypofibrinogenemia (< 1.5 g/L) that persists despite FFP replacement.
UFH or LMWHProphylactic doses of UFH or LMWH are recommended for prevention of venous thromboembolism, and therapeutic doses should be considered for patients with thrombotic complications such as venous or arterial thrombosis, severe purpura fulminans, or vascular skin infarction.Despite the risk of thrombosis, there is little evidence to support the use of prophylactic anticoagulation in patients with acute or chronic DIC, with the exception of the perioperative period or during a hospital admission for an acute medical illness, as done for patients without DIC.ISTH Harmonization: Prophylactic heparin recommended in critically ill, nonbleeding patients; therapeutic heparin may be considered in cases where thrombosis predominates; LMWH recommended over UFH
*American Society of Hematology Self-Assessment Program, Seventh Edition. ** Accessed April 2022. Abbreviations: NM/NA, not mentioned/not applicable; DIC, Disseminated intravascular coagulation; PT, prothrombin time; aPTT, activated partial thromboplastin time; LMWH, low-molecular-weight heparin, UFH, unfractionated heparin; FFP, fresh frozen plasma, ISTH, International Society of Thrombosis and Haemostasis.