* Muscle & joint bleeds indicate a coagulation defect
* purpura, prolonged bleeding from superficial cuts, epistaxis, GI bleeding, menorrhagia, indicate PLT disorder, thrombocytopenia or vW disease
2. Duration: congenital or acquired
3. Precipitating cause: if spontaneous indicate severe defect
4. surgery: dental extraction, tonsillectomy, circumcision. Bleeding immediately after surgery indicate defective PLT plug formation. Bleeding after some hours indicate failure of PLT plug stabilisation by fibrin due to coagulation defect.
5. Family history:
* Hereditary or acquired
* Negative history does not exclude a hereditary cause, as e.g: about 1/3 of cases of hemophilia have negative family history (mutations).
6. Systemic disease:
Hepatic or renal failure
7. Drugs: almost any drug can potentially produce bleeding( cytotoxics. NSAIDs…etc)
Clinical Features of Bleeding Disorders Platelet Coagulation disorders fac disorders Site of bleeding Skin Deep in soft tis. Mucous membranes (joints, musc) Petechiae Yes No Ecchymoses (“bruises”) Small, superficial Large, deep Hemarthrosis / muscle bleeding Extremely rare Common Bleeding after cuts & scratches Yes No Bleeding after surgery or trauma Immediate, Delayed1-2 d usually mild often severe
Petechiae Do not blanch with pressure (cf. angiomas) Not palpable (cf. vasculitis) (typical of platelet disorders)
Screening tests for bleeding disorders
Test Abnormality detected
Blood count and Anaemia, leukaemia, DIC
Platelet count Thrombocytopenia
aPTT Def. of all coagulation factors except
VII, esp. follows VIII and IX; heparin
PT Def. of F I, II, V, VII, and X; warfarin
Thrombin time or Hypo-, dysfibrinogenaemia; heparin
Bleeding time Test of platelet-vessel wall interaction
Causes of bleeding
a- viral infections
c- B12 or folate deficiency
d- ITP, DIC, TTP/HUS ( consumption)
e- BM infiltration: leukemia, MM, Ca, myelofibrosis
2. Clotting factor deficiency:
a- liver disease
b- drugs: warfarin, heparin
c- consumption: DIC
d- dilution: massive blood transfusion
e- congenital: hemophilia..etc
f- vit K deficiency: e.g, malabsorption
3. CT atrophy:
a- old age
b- steroid therapy
4. Vessel wall disorders:
B- Osler-Weber Rendu disease
The lifespan of a platelet is 7-10 days and the normal count for all ages is 150000-450000
Once released from the BM young platelets are trapped in the spleen for up to 36 hours before entering the circulation, where they have a primary haemostatic role.
Congenital abnormalities of platelets can be divided into disorders of platelet production and those of platelet function. All are very rare. In general they cause moderate to severe bleeding problems.
Decreased production of platelets due to suppression or failure of the BM is the commonest cause of thrombocytopenia. In aplastic anaemia, leukaemia and marrow infiltration, and after chemotherapy, thrombocytopenia is usually associated with a failure of red and white cell production but may be an isolated finding secondary to drug toxicity (penicillamine, cotrimoxazole), alcohol, or viral
infection (HIV, infectious mononucleosis). Viral infection is the most common cause of mild transient thrombocytopenia
Increased platelet consumption may be due to immune or non-immune mechanisms.
Post-transfusion purpura (PTP) is a rare complication of blood transfusion. It presents with severe thrombocytopenia 7-10 days after the transfusion and usually occurs in multiparous women who are negative for the human platelet antigen 1a (HPA1a).
Antibodies to HPA1a develop, and in some way this alloantibody is responsible for the immune destruction of autologous platelets.
Neonatal alloimmune thrombocytopenia (NAITP) is similar to haemolytic disease of the newborn except that the antigenic stimulus comes from platelet specific antigens rather than red
cell antigens. In 80% of cases the antigen is human platelet antigen 1a, and mothers negative (about 5% of the population) for this antigen form antibodies when sensitised by a fetus positive for the antigen. Fetal platelet destruction results from transplacental passage of these antibodies and severe bleeding, including intracranial haemorrhage, can occur in utero.
Heparin-induced thrombocytopenia (HIT) occurs during unfractionated heparin therapy in up to 5% of patients, but is less frequently associated with low molecular weight heparins. It may become manifest when arterial or venous thrombosis occurs during a fall in the platelet count and is thought to be due to the formation of antibodies to heparin that are bound to platelet factor 4. The immune complexes activate platelets and endothelial cells, resulting in thrombocytopenia and thrombosis coexisting. Heparin-induced thrombocytopenia carries an appreciable mortality risk if the diagnosis is delayed.
In thrombotic thrombocytopenic purpura (TTP) the presenting features can be fever, fluctuating neurological signs, renal impairment, and intravascular haemolysis, resulting in thrombocytopenia.
The condition is suspected clinically by thrombocytopenia, red cell fragmentation on the blood film, and a reticulocytosis.
Drug induced : heparin, penicillin, quinine, rifampicin,
• Hypersplenism and splenomegaly
• Massive transfusion
Treatment of platelet disorders
• Platelet transfusions (leucodepleted, HLA compatible and irradiated)
• Tranexamic acid
• Recombinant factor VIIa
• Bone marrow transplantation
• Bone marrow failure
Platelet transfusions if platelet count 10000
• ITP (adults)
• Post-transfusion purpura
• Heparin-induced thrombocytopenia
Anticoagulation but without heparin
• Thrombotic thrombocytopenic purpura
Large volume plasma exchange
Aspirin when platelets 50000
Treat underlying cause
Fresh frozen plasma
Splenectomy if severe
• Platelet function disorders
Idiopathic thrombocytopenic purpura(ITP)
It is due to auto- antibodies directed against PLT membrane glycoprotein IIb-IIIa which causes premature removal of PLTs by the monocyte-macrophage system
C/F: 1. in children: sudden onset of purpura, oral or nasal bleeding, usually 2-3 wk after a viral illness
2. In adults: affects females more, with insidious onset, usually not associated with viral infection, but may be associated with CT disease.
It is characterised by remission and relapse.
1. CBC: reduced PLT count
2. BM: increased megakaryocytes
1. In children: usually it is self-limiting, if severe purpura or epistaxis, or PLT <10000 give steroids ( prednisolone 2mg/kg/d)
If pesistent epistaxis GI bleeding, retinal hemorrhage : give PLT transfusion and IV IgG
2. In adults: prednisolone 1 mg/kg/d for 3-4 wk then gradually tapered over 6-8 wk, relapse may occur on tapering
PLT transfusion and IVIg indicated in life-threatening bleeding. If the patient has two relapses , splenectomy is indicated, which is curative in 70% of patients, in the remainder the aim is to keep the patient free of symptoms rather than to raise level of PLT( e.g 5mg/d of prednisolone may be sufficient)
In severe cases iv methylpredinsolone with or without IVIg may be given
If still not controlled give immunosuppressive drugs e.g: vincristine, cyclophosphamide
Factor VIII is synthesized mainly by liver , but also by spleen, kidney, and placenta, carried by vWF, half-life in plasma is 12 hr.
It is sex-linked recessive and affects about 1/10000, thus all daughters of hemophiliacs are carriers and 50% of sisters are carriers. If a carrier has a son, he has 50% chance of having hemophilia and a daughter has 50% chance of being a carrier
At around 6 mon. child develop bruises and hemarthrosis as he starts to move around.
Normal level of factor VIII is 50%-150%, and severity is measured according to this level:
1. severe: <1% F VIII or IX: liable for spontaneous hemarthrosis & muscle hematoma
2. Moderate : 1-5% F VIII or IX: mild trauma or surgery causes hematoma
3. mild: 6-50% F VIII or IX: major surgery or injury results in excess bleeding.
Joints commonly affected include: knees, elbows, ankles, and hips.
They look hot, swollen, and very painfull and tender.
With recurrent bleeding there will be synovial hypertrophy, destruction of cartilage and secondary osteoarthritis,
In muscles : calf, psoas: bleeding lead to ischemia, necrosis, fibrosis which will lead to contracture & shortening of tendons e.g achilles tendon making walking difficult.
Shortening of Achilles tendon
Dosing guidelines for hemophilia A
Mild bleeding :
Target: 30% dosing q8-12h; 1-2 days (15U/kg)
Hemarthrosis, oropharyngeal or dental, epistaxis, hematuria
Target: 80-100% q8-12h; 7-14 days (50U/kg)
CNS trauma, hemorrhage, lumbar puncture
Adjunctive therapy :
-aminocaproic acid or DDAVP (for mild disease only)
Von Willebrand’s disease
Usually it is a mild bleeding disorder of many types, the commonest being type I which is autosomal dominant.
vWF is synthesized by endothelial cells and megakaryocytes and has two functions: 1. carrier for F VIII and 2. form bridges between PLT and subendothelial collagen
Bruising, epistaxis, menorrhagia, GI bleeding
* Decreased level of vWF, increased bleeding time, increased PTT
Treatment of von Willebrand Disease
Source of fibrinogen, factor VIII and VWF
Only plasma fraction that consistently contains VWF multimers
DDAVP (deamino-8-arginine vasopressin)
plasma VWF levels by stimulating secretion from endothelium
Duration of response is variable
Not generally used in type 2 disease
Dosage 0.3 µg/kg q 12 hr IV
Factor VIII concentrate (Intermediate purity)
Virally inactivated product
Common clinical conditions associated with DIC
Trauma : Head injury , Fat embolism
Obstetrical complications :
Amniotic fluid embolism
Reaction to toxin (e.g. snake venom, drugs)
Severe allergic reaction
Activation of both coagulation and fibrinolysis
Pathogenesis of DIC Coagulation Fibrinolysis Fibrinogen Fibrin Monomers Fibrin Clot (intravascular) Fibrin(ogen) Degradation Products Plasmin Thrombin Plasmin Release of thromboplastic material into circulation Consumption of coagulation factors; presence of FDPs aPTT PT TT Fibrinogen Presence of plasmin FDP Intravascular clot Platelets Schistocytes
DIC Treatment approaches
Treatment of underlying disorder
Anticoagulation with heparin
Fresh frozen plasma
Coagulation inhibitor concentrate (ATIII)
Management of Hemostatic Defects in Liver Disease
Treatment for prolonged PT/PT
Vitamin K 10 mg x 3 days - usually ineffective
Fresh-frozen plasma infusion (1200-1500 ml)
immediate but temporary effect
Treatment for low fibrinogen
Cryoprecipitate (1 unit/10kg body weight)
Treatment for DIC (↑ D-dimer, ↓ factor VIII, thrombocytopenia