haematology - bleeding disorders Flashcards
approaches to bleeding disorders
- bleeding patient
- can have normal initial labs - abnormal bleeding tests
- little clinical sig without Hx of bleeding
broad classification of bleeding disorders
congenital
acquired
vascular defects
platelet disorders
coagulation disorders
features of vascular defects
superficial bleeding into skin and mucosal membranes
bleeding immediately after injury
features of platelet disorders
superficial bleeding into skin and mucosal membranes
bleeding immediately after injury
features of coagulation disorders
bleeding into deep tissues, muscles, and joints
delayed but severe bleeding after injury
prolonged bleeding
examples of congenital vascular defects
Osler-Weber-Rendu syndrome
connective tissue disease, eg. EDS
examples of acquired vascular defects
senile purpura
steroids
scurvy (perifollicular haemorrhages)
infection (eg. meningococcal measles, dengue)
platelet disorder classification
decreased function
- acquired
- congenital
decreased number
- decreased production
- increased destruction
causes of acquired decreased platelet function
aspirin
cardiopulmonary bypass
uraemia
causes of congenital decreased platelet function
storage pool disease
thrombasthenia (glycoprotein deficiency)
causes of thrombocytopenic platelet disorders with decreased production
bone marrow failure
causes of thrombocytopenic platelet disorders with increased destruction
autoimmune thrombocytopenia purpura (AITP) drugs, eg. heparin DIC HUS TTP
peak age of acute ITP vs chronic ITP
acute: 2-6 years
chronic: adults
F:M of acute ITP vs chronic ITP
acute: 1:1
chronic: 3:1
preceding infection in acute ITP vs chronic ITP
acute: common
chronic: rare
onset of symptoms of acute ITP vs chronic ITP
acute: abrupt
chronic: abrupt - indolent
platelet count at presentation in acute ITP vs chronic ITP
acute: <20,000
chronic: <50,000
duration of acute ITP vs chronic ITP
acute: 2-6 weeks
chronic: long term (associated with autoimmune disease, CLL, HIV)
spontaneous remission of acute ITP vs chronic ITP
acute: common, self limiting
chronic: uncommon
treatment of chronic ITP
IVIg
steroids
splenectomy
examples of inherited coagulation disorders
haemophilia A
haemophilia B
Von Willebrand’s Disease
haemophilia A
factor VIII deficiency
inheritance pattern of haemophilia A
X linked recessive
rarely acquired
presentation of haemophilia A
often early in life or prolonged bleeding after surgery/trauma
dx of haemophilia A
↑ APTT
normal PT
↓ factor VIII assay
severity of haemophilia A depends on
factor level
<1%: severe
1-5%: moderate
5-25%: mild
management of haemophilia A
avoid NSAIDS and IM injections
desmopressin
factor VIII concentrates replacement
desmopressin in treatment of haemophilia A
↑ VWF release which is factor VIII carrier
haemophilia B
factor IX deficiency
inheritance pattern of haemophilia B
X linked recessive
clinical presentation of haemophilia B
similar to that of haemophilia A
management of haemophilia B
factor IX concentrates
Von Willebrand’s Disease
factor VIII deficiency and ↓ platelet function
types of VWD
quantitative
qualitative
variable phenotype (from complete to asymptomatic/mild deficiency) type 1: low levels of VWF type 2: deficiency in VWF function type 3: absent VWF
inheritance pattern of VWD
autosomal dominant
presentation of VWD
mucocutaneous bleeding
bleeding indicative of coagulation disorders
dx of VWD
(↑) APTT normal PT ↓ factor VIII (↓) vWF antigen normal platelet count
management of VWD
prophylaxis indicated in some patients
treatment of bleeds
- desmopressin
- VWF concentrate
- factor VIII concentrate
examples of coagulation disorders
DIC
liver disease
vit K deficiency
DIC
widespread activation of coagulation
↓ clotting factors and platelets
causes of DIC
malignancy sepsis trauma obstetric complications toxins
dx of DIC
↓ platelets
↓ fibrinogen
↑ D dimer
↑ PT
treatment of DIC
treat cause transfusions FFP platelets cryoprecipitate
liver disease coagulation disorder
↓ synthesis of II, V, VII, IX, V, VI and fibrinogen
↓ absorption of vit K
abnormal platelet function
vit K deficiency coagulation disorder
vit K needed for factors II, VII, IX, X and protein C/S
warfarin may have what effect initially
pro-coagulant because vit needed for protein C/S
causes of vit K deficiency coagulation disorder
warfarin
vit K malabsorption/malnutrition
Abx therapy
biliary obstruction
treatment of vit K deficiency coagulation disorder
IV vitamin K
FFP for acute haemorrhage
↑/= APTT
= PT
= bleeding time
= fibrinogen
= D dimer
= platelet count
vit K deficiency
warfarin
= APTT
= PT
↑ bleeding time
= fibrinogen
= D dimer
= platelet count
aspirin
thienopyridines
= APTT
↑ PT
= bleeding time
= fibrinogen
= D dimer
= platelet count
early stage liver failure
↑ APTT
↑ PT
↑ bleeding time
↓ fibrinogen
↑ D dimer
↓ platelet count
end stage liver failure
= APTT
= PT
↑ bleeding time
= fibrinogen
= D dimer
= platelet count
uraemia
↑ APTT
↑ PT
↑ bleeding time
↓ fibrinogen
↑ D dimer
↓ platelet count
DIC
= APTT
= PT
↑ bleeding time
= fibrinogen
= D dimer
↓↓ platelet count
TTP
↑ APTT
↑ PT
(↑) bleeding time
↓ fibrinogen
↑↑ D dimer
= platelet count
hyperfibrinolysis
vit K deficiency
warfarin
clotting screen
↑/= APTT
= PT
= bleeding time
= fibrinogen
= D dimer
= platelet count
aspirin
thienopyridines
clotting screen
= APTT
= PT
↑ bleeding time
= fibrinogen
= D dimer
= platelet count
early stage liver failure
clotting screen
= APTT
↑ PT
= bleeding time
= fibrinogen
= D dimer
= platelet count
end stage liver failure
clotting screen
↑ APTT
↑ PT
↑ bleeding time
↓ fibrinogen
↑ D dimer
↓ platelet count
uraemia
clotting screen
= APTT
= PT
↑ bleeding time
= fibrinogen
= D dimer
= platelet count
DIC
clotting screen
↑ APTT
↑ PT
↑ bleeding time
↓ fibrinogen
↑ D dimer
↓ platelet count
TTP
clotting screen
= APTT
= PT
↑ bleeding time
= fibrinogen
= D dimer
↓↓ platelet count
hyperfibrinolysis
clotting screen
↑ APTT
↑ PT
(↑) bleeding time
↓ fibrinogen
↑↑ D dimer
= platelet count
