Disclaimer:
The referenced guideline was last reviewed over 10 years ago. However, the core principles outlined remain relevant and appropriate for non-specialist level learning.
Definition
DIC is a clinicopathological syndrome that is characterised by systemic activation of the coagulation system, resulting in:
- Widespread intravascular (microvascular) clot formation → organ failure
- Consumption of platelets and clotting factors → serious bleeding
- Often accompanied by secondary activation of fibrinolysis
Aetiology
DIC never occurs in isolation, it always arises as a secondary complication of an underlying disorder that triggers systemic activation of the coagulation system.
Common / important causes:
- Sepsis – a common cause of DIC
- Acute pancreatitis
- Severe burns
- Malignancy (classically APLAcute pro-myelocytic leukaemia)
- Major trauma / severe burns
- Obstetric causes (e.g. placental abruption, HELLP syndrome)
- Toxins (e.g. snake bites, recreational drug use)
- Immunological causes (e.g. acute haemolytic transfusion reaction, transplant rejection)
Clinical Manifestation
DIC paradoxically presents with BOTH bleeding and thrombosis, due to consumption of platelet and clotting factors (→ bleeding) and widespread microvascular thrombosis (→ thrombosis).
| Bleeding manifestations |
|
| Thrombotic manifestations |
|
DIC = bleeding + thrombosis in a critically unwell patient
Investigation and Diagnosis
Typical findings in DIC:
| Investigation | Finding in DIC | Rationale |
|---|---|---|
| Platelet count | ↓ LOW | Consumption of platelets due to widespread clot formation |
| Prothrombin time (PT) | ↑ PROLONGED | Consumption of clotting factors due to widespread activation of coagulation |
| Activated partial thromboplastin time (APTT) | ↑ PROLONGED | |
| Fibrinogen | ↓ LOW | Consumption in formation of fibrin clots |
| D-dimer | ↑ HIGH | Increased fibrinolysis → breakdown of fibrin clots |
| Blood film | Schistocytes (not sensitive or specific to DIC) | Microangiopathic haemolysis due to fibrin strands shearing RBCs |
Diagnosis of DIC is based on the clinical context (i.e. underlying disorder associated with DIC) and supportive laboratory findings
- No single test can definitively diagnose or exclude DIC, a combination of tests (see below) is necessary
- DIC is a dynamic condition → laboratory tests should be repeated serially
- Formal scoring systems (e.g. ISTH DIC score) and advanced markers (e.g. APTT biphasic waveform) may support diagnosis, but are out of scope at a non-specialist level
Management
Corestone of DIC management: treating the underlying disorder
In many cases, DIC will resolve spontaneously once the primary cause is properly managed
Blood Component Therapy
Supportive blood component therapy should NOT be given based on laboratory results only, they are indicated in patients with:
- Active bleeding
- Requiring invasive procedures
- At high risk of bleeding complications
3 main types of blood components are used in DIC (if indicated):
| Blood component | Indication |
|---|---|
| Platelets | Bleeding / high-risk patients with low platelet count |
| Fresh frozen plasma (FFP) | Bleeding / procedures with prolonged PTProthrombin time / APTTActivated partial thromboplastin time |
| Cryoprecipitate | Bleeding with low fibrinogen |
PCCProthrombin complex concentrate is not routinely used in DIC and is inferior to FFPFresh frozen plasma. It should only be considered if FFPFresh frozen plasma is not feasible (e.g. fluid overload), as it only partially corrects the coagulopathy and does not replace all depleted clotting factors (e.g. factor V).
In contrast, PCCProthrombin complex concentrate is preferred over FFPFresh frozen plasma for rapid reversal of warfarin in severe haemorrhage.
Anticoagulation Therapy
Therapeutic heparin is indicated when thrombosis predominates (e.g. severe purupa fulminas, arterial / venous thromboembolism)
- UFHUnfractionated heparin is often preferred in patients with a co-existing high risk of bleeding
- Prophylactic heparin is recommended for critically ill, non-bleeding patients to prevent venous thromboembolism
Antifibrinolytic agents (e.g. tranexamic acid) should generally be avoided in DIC, as they may worsen fibrin deposition and microvascular thrombosis
Exception: it may be considered in rare cases with primary hyperfibrinolytic state (e.g. APLAcute promyelocytic leukaemia) with severe bleeding, however this is beyond the scope of a non-specialist level.
References
BSH Guidelines for the diagnosis and management of disseminated intravascular coagulation