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Disseminated Intravascular Coagulation (DIC)

For medical students2 min readUpdated 2026-10-10

Disseminated intravascular coagulation (DIC) is a severe thrombohemorrhagic disorder characterized by an initial phase of systemic microvascular thrombosis followed by the exhaustion of clotting factors and profuse bleeding. It invariably acts as a "secondary disease," complicating the course of critical conditions and terminal pathologies.

Mortality RateReaches 40–60% due to multiple organ dysfunction syndrome (MODS) and acute blood loss.
Core ProcessA mosaic phase transition: from hypercoagulation to severe hypocoagulation.
Primary TargetThe microcirculatory system (formation of microthrombi and total ischemia).
Basis of TherapyElimination of the root cause (etiotropic treatment of the underlying condition).

Etiology: What Triggers the Process?

The syndrome is rooted in the inappropriate activation of the coagulation cascade, triggered via two main pathways:

Additional potent triggers include intravascular hemolysis (incompatible blood transfusion, hemolytic poisons) and oncological processes (solid tumors, hematologic malignancies).

Stages of Pathogenesis

The process develops rapidly, often taking an "explosive" course, and proceeds through three sequential phases:

  1. Hypercoagulation and Thrombosis Stage. Lasts relatively briefly. Fibrin is massively formed within blood vessels, and platelets aggregate, forming loose and true microthrombi. The result is the blockade of microcirculatory beds. Tissue ischemia leads to hypoxia and metabolic acidosis, which activates proteolysis, further driving coagulation via positive feedback. Clinically, skin pallor and tachypnea are noted; laboratory findings show hyperprothrombinemia and shortened clotting time.
  2. Consumption Coagulopathy Stage. Due to total microthrombosis, the body critically depletes its reserves of procoagulants and platelets. Hypofibrinogenemia and progressive thrombocytopenia develop.
  3. Hypocoagulation and Fibrinolysis Stage. In response to excess fibrin, a powerful compensatory fibrinolysis is triggered. Antithrombin III levels drop, and fibrin degradation products (FDPs) accumulate in the blood, exerting an intrinsic anticoagulant effect. A severe hemorrhagic syndrome emerges: profuse bleeding from damaged vessels and spontaneous hemorrhages into intact tissues.

Complications and Causes of Mortality

The primary threat in DIC is the development of multiple organ dysfunction syndrome (MODS) driven by ischemia and subsequent hemorrhages. The main causes of patient death include:

Principles of Treatment

Because DIC is secondary, absolute priority is given to etiotropic therapy: the underlying cause must be eliminated (administering antibiotics for sepsis, resolving the obstetric emergency, halting hemolysis).

Pathogenetic treatment aims to correct the hemostatic system and depends on the specific phase:

To support vital functions:

  1. Restoration of circulating blood volume (CBV) using isotonic sodium chloride solution (avoiding cardiac overload to prevent pulmonary edema).
  2. Correction of gas exchange and acid-base balance (ABB) (oxygen inhalation, sodium bicarbonate administration for acidosis).
  3. Renal support (vasopressors for hypotension, hemodialysis for developing AKI).
  4. Detoxification (plasmapheresis to remove FDPs, bacterial toxins, and immune complexes).

Mnemonic

Remember the stages using the acronym PIC: Proliferated clotting (hypercoagulation) → Intermediate factor exhaustion (consumption coagulopathy) → Cleeding/Bleeding (hypocoagulation and fibrinolysis).

Frequently asked questions

What obstetric conditions trigger the extrinsic pathway of DIC?

The extrinsic pathway of DIC in obstetric pathology is associated with massive tissue damage and the release of factors that stimulate the hemostatic system. Documented obstetric conditions include:

  • Placental abruption.
  • Placenta previa and uterine rupture.
  • Amniotic fluid embolism.
  • Atonic postpartum hemorrhage.
  • Intrauterine fetal demise.
  • Destructive obstetric operations.
What stages are distinguished in the pathogenesis of DIC?

The pathogenesis of DIC is divided into several sequential stages reflecting the dynamics of blood coagulation disorders:

  • Stage I — Hypercoagulation and thrombosis — characterized by intravascular protein clotting, platelet adhesion and aggregation, leading to microthrombus formation.
  • Stage II — Progressive consumption coagulopathy — marked by significant utilization of procoagulants and platelets, leading to their depletion.
  • Stage III — Profound hypocoagulation and activation of fibrinolysis — a decompensated phase with the development of pathological fibrinolysis and hemorrhagic syndrome.
What laboratory markers indicate the hemorrhagic stage of DIC?

The development of the hemorrhagic stage (hypocoagulation phase) of DIC is indicated by markers of clotting factor depletion and fibrinolysis activation. The main ones include:

  • Hypofibrinogenemia — a significant decrease in blood fibrinogen levels.
  • Thrombocytopenia — a critical reduction in platelet count due to their excessive consumption.
  • Antithrombin III deficiency — a critical drop in natural anticoagulant levels.
  • Elevated FDP levels — a substantial increase in fibrin and fibrinogen degradation products.
Which medications are used for the pathogenetic treatment of the hypercoagulation stage?

For the pathogenetic treatment of the hypercoagulation stage of DIC in the absence of active bleeding, anticoagulants are used.

Agents indicated for Stage I include:

  • Low-molecular-weight heparins: enoxaparin sodium, nadroparin calcium.
  • Heparin sodium — as part of regimens to normalize hemostasis in DIC.
What is transfused to patients during the hemorrhagic phase of DIC?

During the hemorrhagic phase of DIC, patients are transfused with blood components to restore coagulation potential and normalize hemostasis. The main transfusion media are:

  • Platelet concentrate — administered for hemorrhagic syndrome combined with critical thrombocytopenia.
  • Fresh frozen plasma (FFP) — administered intravenously to replenish preserved plasma clotting factors.
  • Native plasma — also used to normalize hemostasis and combat coagulopathy.
Why does DIC cause bleeding if blood initially clots actively?

Due to consumption coagulopathy. In the first phase, the body expends nearly all platelets and plasma factors to form microthrombi. When reserves are depleted and clot breakdown (fibrinolysis) is triggered in response, the blood completely loses its ability to clot.

What laboratory markers indicate the hemorrhagic stage?

A sharp drop in fibrinogen levels, a critical decline in antithrombin III, marked thrombocytopenia, and a significant elevation in fibrin degradation products (FDPs).

Can DIC be treated solely with blood component transfusions?

No, because it is a complication of an underlying disease. Without etiotropic treatment (eliminating the root cause, such as sepsis, shock, or an obstetric pathology), halting the pathological cascade is impossible.

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