hemophilia lecture by dr. tariq saeed
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HEMOPHILIA
DR. TARIQ SAEEDAssistant ProfessorPaediatric DepartmentHoly Family Hospital Rawalpindi
Definition
Hemophilia A (factor VIII deficiency) and
hemophilia B (factor IX deficiency)
Rare bleeding disorders due to inherited deficiencies
of coagulation factors
Types
Haemophilia A (Classic) Factor VIII deficiency
Haemophilia B (Christmas Disease) Factor IX deficiency
Hemophilia A & B
clinically similar:
occur in approximately 1 in 5,000 male births
account for 90% of congenital bleeding disorders
Hemophilia A is approximately 5 times more common than B
Etiology
Inherited as a sex linked recessive trait with bleeding manifestations only in males
genes which control factor VIII and IX production are located on the x chromosome; if the gene is defective synthesis of these proteins is defective
female carriers transmit the abnormal gene
PATHOPHYSIOLOGY
Factors VIII and IX participate in a complex required for the activation of factor X.
After injury, the initial hemostatic event is formation of the platelet plug, together with the generation of the fibrin clot that prevents further hemorrhage. In hemophilia A or B, clot formation is delayed and is not robust.
Disease Severity
severity is dependent on blood levels of functioning factor VIII or IX
severity varies markedly between families but is relatively constant among family members in successive generations
remains relatively unchanged throughout life
Classification
% normal factor level
Causes of bleeding
Severe < 1% bleeding after trivial injury or spontaneous
Moderate 1 - 5% bleeding after minor injury; occasional spontaneous bleeds
Mild 6 - 30 % following major trauma, surgical or dental procedures
Clinical Features – Joint Bleeds
Joints (Hemarthrosis) Knees, ankles and elbows most common sites begin as the child begins to crawl and walk many bleeds occur between the ages of 6 and 15
years Single joint bleed: stiffness, swelling, pain, loose
pack position
Sub Acute Hemarthrosis
Develops after repeated bleeds into the joint Synovium becomes inflamed Hypertrophy, hyperplasia and increased
vascularity of synovial membrane Hemosiderosis: hemoglobin of intra articular
blood is degraded and iron deposited into the joint space
Chronic Arthropathy
Progressive destruction of a joint Pannus (inflammed synovium), & enzymes
begin to destroy articular cartilage Microfracture and cyst formation in
subchondral bone End stage: firbrous joint contracture, and
disorganization of articular surfaces
Clinical Features – Muscle Bleeds
Bleeding into muscle or soft tissue Less tendency to recurrent bleeds Sites: iliopsoas, calf, upper arm and forearm,
thigh, shoulder area, buttock Symptoms: pain, swelling, muscle spasm Complications: nerve compression,
contracture
Other Sites of Hemorrhage
Abdomen GI tract Intracranial bleeds Around vital structures in the neck
LABORATORY FINDINGS AND DIAGNOSIS
Factor VIII or factor IX deficiency leads to prolongation of APTT.
In severe hemophilia, APTT is usually 2–3 times the upper limit of normal.
All other screening tests of with in normal limit.
The specific assay for factors VIII and IX will confirm the diagnosis of hemophilia.
Management
Replacement of missing clotting factor Plasma products Cryoprecipitate Concentrates of Factor VIII Factor IX
Early, appropriate therapy is the hallmark of excellent hemophilia care.
Mild to moderate bleeding, levels of factor VIII or factor IX must be raised to hemostatic levels in the 35–50% range.
For life-threatening or major hemorrhages, the dose should aim to achieve levels of 100% activity.
Role of Desmopressin in Hemoplhilia A
With mild factor VIII hemophilia, the patient's endogenously produced factor VIII can be released by the administration of desmopressin acetate.
Other Medical Treatment
Analgesics (no aspirin) Good dental care Education – life long management Psychological counseling Acute and long term management of
musculoskeletal problems
Musculoskeletal Management
Acute Bleeds: Immediate replacement factor Immobilize joint No weight bearing Immediate medical attention if complications arise
Musculoskeletal Management
After 24 hours: Continue minimal or no weight bearing for lower
extremity bleed Active range of motion; gentle stretching Corrective positioning (splinting ??) Isometric strengthening; progress to isotonic
Musculoskeletal Management
Long term: Repeated musculoskeletal examination (annual or
biannual) Measurement of leg length, girth, ROM, strength,
gait, function Physiotherapy treatment: based on assessment
findings Prophylactic factor replacement
usually provided every 2–3 days to maintain a measurable plasma level of clotting factor (1–2%) when assayed just before the next infusion (trough level).
Education of Patient and Family
Importance of early factor replacement Use of helmet when riding tricycle/bicycle Sports: contact sports discouraged for
severe hemophiliacs; swimming, cross country skiing, tennis, golf, baseball, bicycling – generally considered safe
Footwear
CHRONIC COMPLICATIONS
Long-term complications of hemophilia A and B include
Chronic arthropathy Development of an inhibitor to either factor
VIII or factor IX, Risk of transfusion-transmitted infectious
diseases.