DIC

Question 1

When does acute DIC occur

Answer 1

• Acute DIC occurs when large amounts of tissue factor are released over a short duration, not allowing for compensatory increase in platelets/ factors
  Profound bleeding from lines, catheters, surgical sites

Question 2

What is DIC

Answer 2

Widespread acitvation of intravascular coagulation in small and medium vessles not localised
Inhibiton of fibrinolysis and depletion in physiological anticaogulants

Question 3

MOA of DIC

Answer 3

Trigger-> formation blood clots in small vessles
Depletion of clotting factors and platelets in clots -> increased bleeding risk
Breakdown of clots inhibited - inhibited fibrinolysis
BOTH CLOTTING AND BLEEDING

Question 4

Conditions causing DIC

Answer 4

Create or release prothrombotic factors
Sepsis
Cancer - APL, disseminated adenocarcinoma
Obstetric causes eg amniotic fluid embolism
Shock
Extensive surgery

Question 5

How do diseases cause DIC

Answer 5

Sepsis - LPS on surface of gram negative bacteria thrombotic
Cancer - tissue factor on tumour cells
Obstetric - eg reatined placental products, placental disrution -> tissue factors enter maternal circulation
Shock - ischaemic injury -> exression of tssue factor intravascuarly

Question 6

DIC outcomes

Answer 6

Higher rates of mortality and morbidity than underlying conditions

Question 7

Lab tests in DIC

Answer 7

Prolonged APTT and PT
Lowered fibrinogen and platelets
V high D-dimer

Question 8

Why is it important to ask for Clauss fribrinogen in DIC or major haemorrhage

Answer 8

Abnormal PT/APTT means inaccurate fibrinogen derived from clotting screen

Question 9

Presenting features of DIC

Answer 9

Sick patient
Bleeding from venepuncture sites
New VTE rarely
Organ dysfunction due to microvascular thrombus

Question 10

What score use in DIC

Answer 10

ISTH

Question 11

Parameters for DIC score

Answer 11

Platelet count
D-dimer
PTT
Fibringoen

Question 12

What score indicates DIC in ISTH

Answer 12

> 5
3-4 doesnt rule out - eveolving syndrome

Question 13

Treating DIC

Answer 13

Treat underlying cause
Mainatin haemosatsis

Question 14

Basic treatment DIC

Answer 14

IV vit K replacement support production of clotting factors
Maintain physiological pH and Ca levels
Maintain body temp

Question 15

When replace blood in DIC

Answer 15

Severe bleeding

Question 16

What give in severe bleeding in DIC

Answer 16

1 pool of platelets if <75
2 pools cryoprecipitate if fibrinogen <1.5
4 U FFP to replace coag factors and natural anticoags

Question 17

What causes DIC

Answer 17

Massive activation of clotting cascade due to TF release, overwhelm antithrombotic pathways

Question 18

What causes bleeding in DIC

Answer 18

• Consumption of platelets and factors, due to secondary hyperactivation of fibrinolysis, leads to bleeding

Question 19

What anaemia is seen in DIC

Answer 19

• Shearing of red blood cells over intravascular fibrin strands leads to microangiopathic haemolytic anaemia (MAHA)

Question 20

Less common causes DIC

Answer 20

paroxysmal nocturnal haematuria, acute haemolytic transfusion reactions, purpura fulminans, catastrophic antiphospholipid syndrome, hepatic failure, aortic aneurysm, hyperthermia, giant haemangiomas, peritoneal venous shunts, snake venoms, amphetamines

Question 21

Chronic DIC cause

Answer 21

Sall amounts TF released over time - compensatory increase in platelet and factors but also build up of procagulants
Asymptomatic or microvascular, arterial or venous thrombi -> end organ damage

Question 22

Differnetials for DIC

Answer 22

MAHA: TTP/HUS, HELLP, vasculitis, scleroderma, hypertensive crisis, etc. (normal coagulation studies)
Liver failure (can coexist with DIC)
HIT (normal coagulation studies)

Question 23

Baseline investigations DIC

Answer 23

FBC, blood film, LDH, bilirubin, haptoglobin, reticulocyte count, INR, APTT, fibrinogen, liver enzymes, creatinine
β-HCG, septic work up as appropriate for clinical situation

Question 24

When is heparin used in DIC

Answer 24

management of thrombosis in patients with chronic DIC.