QuestionSBA
QuestionChoice
TMA is characterised by the formation of thrombi in the small vasculature and associated microangiopathic haemolytic anaemia (MAHA) due to fragmentation of red blood cells. TMA alone would not be associated with clotting abnormalities (i.e. raised PT and APTT)
32354
b
Secondary thrombotic microangiopathy (TMA) due to infection
QuestionChoice
ITP is characterised by an isolated thrombocytopenia in the absence of an identifiable cause. Therefore, clotting would be normal
32356
d
Immune thrombocytopenic purpura (ITP)
QuestionChoice
Sepsis and trauma can lead to low platelets due to a 'consumptive state'. However, this would not be associated with clotting abnormalities
32357
e
Consumptive thrombocytopaenia due to infection
QuestionChoice
MAHA is associated with intravascular haemolysis and can be seen in conjunction with a thrombotic microangiopathy (TMA) or disseminated intravascular coagulation (DIC). MAHA alone (e.g. due to haemolysis secondary to prosthetic heart valves) is not associated with low platelets or clotting abnormalities
32355
c
Microangiopathic haemolytic anaemia (MAHA)
QuestionChoice
DIC is a life-threatening complication of sepsis. It results from over-activation of the coagulation pathway leading to increased risk of thrombosis and subsequent risk of bleeding due to depletion of clotting factors and platelets. It is characterised by raised PT, APTT and D-Dimer, and low platelet count and fibrinogen level. Treatment is supportive with blood products and treatment of the underlying cause
32353
a
Disseminated intravascular coagulation (DIC)
Concept
Chapter
# Summary


Disseminated intravascular coagulation (DIC) is a haematological emergency, characterized initially by the inappropriate activation of the clotting cascades, leading to thrombus formation (in microvasculature) and depletion of clotting factors and platelets, which then results in bleeding. Key signs and symptoms include excessive bleeding (such as epistaxis, gingival bleeding, haematuria, and bleeding from cannula sites), fever, confusion, and potential coma. The physical signs include petechiae, bruising, confusion, and hypotension. Key investigations include testing for thrombocytopenia, increased prothrombin time, increased fibrin degradation products (such as D-dimer), and decreased fibrinogen. Management strategies revolve around treating the underlying cause and supportive care.


# Definition


Disseminated intravascular coagulation (DIC) is a complex condition that describes the inappropriate activation of the clotting cascades, resulting in thrombus formation and subsequently leading to the depletion of clotting factors and platelets.


# Epidemiology


DIC often occurs in the context of severe systemic disease (see aetiology below). DIC is often encountered in a hospital setting, particularly in intensive care units, surgical wards, and obstetric units due to the high prevalence of associated risk factors. It is associated with a high mortality rate, with the outcome is largely dependent on the prompt diagnosis and treatment of the underlying cause.


# Aetiology


- Major trauma or burns
- Multi-organ failure
- Severe sepsis or infection
- Severe obstetric complications
- Solid tumours or haematological malignancies 
- **Acute promyelocytic leukaemia (APL)** is an uncommon subtype of AML that is associated with DIC 
- **Note**: This comes up frequently in written exams


# Signs and Symptoms


Patients with DIC commonly present with:


- Excessive bleeding e.g. epistaxis, gingival bleeding, haematuria, bleeding/oozing from cannula sites
- Fever
- Confusion
- Potential coma


Physical signs include:


- Petechiae
- Bruising
- Confusion
- Hypotension


# Differential Diagnosis


The differential diagnosis for DIC includes conditions that cause similar symptoms such as:


- Other coagulopathies, which may also present with excessive bleeding and bruising
- Sepsis, which can cause fever, confusion, and hypotension
- Multi-organ failure, which can cause a similar range of systemic symptoms including confusion and hypotension


# Investigations


- Blood tests, including:
- FBC (thrombocytopenia)
- Blood film may show schistocytes due to microangiopathic haemolytic anaemia (MAHA)
- Raised d-dimer (a fibrin degradation product)
- Clotting profile - increased prothrombin time (due to consumption of clotting factors), increased APTT, decreased fibrinogen (consumed due to microvascular thrombi)


# Management


Management of DIC is primarily focused on treating the underlying cause. Supportive care is also essential to manage symptoms and prevent complications. This may include transfusions of platelets or clotting factors, and in some cases, anticoagulation therapy may be necessary.
387
391
Disseminated intravascular coagulation (DIC)
Topic
8
Haematology
Video
Concept
391
Disseminated intravascular coagulation (DIC)
97
j2JJJgK
images/videos/hematology.png
Disseminated intravascular coagulation (DIC) 1
Video
Concept
391
Disseminated intravascular coagulation (DIC)
98
CkStHE2
images/videos/hematology.png
Disseminated intravascular coagulation (DIC) 2
Video
Concept
391
Disseminated intravascular coagulation (DIC)
319
dY59e7q
images/videos/hematology.png
Quesmed Tutorial: Haematology
Video
Concept
391
Disseminated intravascular coagulation (DIC)
320
xsyPfpT
images/videos/hematology.png
Quesmed Tutorial: Haemolytic Anaemia
6471
Disseminated intravascular coagulation (DIC) is a severe complication of sepsis, characterised by coagulopathy and multi-organ dysfunction.
A 56-year-old man is being treated for Escherichia coli septicaemia secondary to pyelonephritis. He is currently on day three of treatment with gentamicin but continues to have fevers and rising inflammatory markers. In addition, his most recent blood tests show a low platelet count, low fibrinogen and raised prothrombin (PT) and activated partial thromboplastin (aPTT) times.

Which of the following is the most likely explanation for the patient's blood test results?
a