Chapter 30 Flashcards
What is the most common blood disorder in children and what are the general causes?
Most common blood disorder in children is Anemia.
Results from inadequate erythropoiesis (decreased red blood cell production) or early destruction of erythrocytes (hemolysis)
What is iron deficiency anemia, and what are its common causes in different age groups?
deficiency of iron
common causes:
-infants and young children: inadequate iron intake, excessive consumption of cows milk can be a predisposing factor in developed counties
- childhood and adolescence: Blood loss is the most common cause. other causes include problems with iron absorption and increased iron requirements.
Describe the pathophysiology of Iron Deficiency Anemia (IDA). What type of anemia does it produce?
In IDA, a deficiency of iron leads to the production of red blood cells that are hypochromic (pale) and microcytic (small). This is because iron is essential for hemoglobin synthesis.
Low serum levels of ferritin (an iron storage protein) and transferrin saturation (a measure of iron bound to transferrin, the iron transport protein) result in lowered hemoglobin and hematocrit levels.
What are some clinical manifestations of Iron Deficiency Anemia (IDA) in children?
Symptoms of mild to moderate IDA can be non-specific and may include:
*Listlessness and fatigue
*General irritability, decreased activity tolerance, weakness, and lack of interest in play
*Pallor (paleness)
More severe or chronic IDA can lead to:
*Splenomegaly (enlarged spleen)
*Widened skull sutures
*Decreased physical growth and developmental delays
*Pica (eating non-food substances)
How is Iron Deficiency Anemia (IDA) typically evaluated and treated in children?
Evaluation of IDA involves:
*Laboratory tests: Measuring hemoglobin, hematocrit, serum iron, ferritin levels, and total iron-binding capacity.
*A thorough history of the child’s illness and dietary habits, and a complete physical examination.
Treatment typically includes:
*Oral administration of a simple ferrous salt (iron supplement), often taken with a vitamin C source to aid absorption.
*Dietary modification: Increasing intake of iron-rich foods and potentially restricting cow’s milk intake to a specific amount per day.
*Iron therapy is usually continued for at least 2 months after erythrocyte indexes have returned to normal to replenish iron stores.
What are some causes of anemia due to blood loss in children mentioned in the source?
The source mentions that anemia due to blood loss can result from:
*Trauma
*Gastrointestinal lesions
*Parasitic infestation
*Hemorrhagic disease
Chronic IDA can be a consequence of occult (hidden) blood loss from these causes
Describe anemia of inflammation as mentioned in the source. What type of anemia is it typically?
The source indicates that anemia can result from decreased erythropoiesis despite a normal stem cell population in the bone marrow in the context of infection, inflammation, cancer, chronic renal disease, or congenital dyserythropoiesis.
This type of anemia is typically normocytic-normochromic anemia (red blood cells are of normal size and color but reduced in number).
What are the two main categories of disorders of coagulation and platelets discussed in the source?
The two main categories of disorders of coagulation and platelets discussed are:
*Inherited hemorrhagic diseases, such as the hemophilias.
*Antibody-mediated hemorrhagic diseases, which include immune thrombocytopenia, autoimmune neonatal thrombocytopenias, and autoimmune vascular purpuras.
What is Primary Immune Thrombocytopenia (ITP), and what is its pathophysiology?
Primary Immune Thrombocytopenia (ITP) is a disorder of platelet consumption where autoantibodies bind to the plasma membranes of platelets.
Pathophysiology:
*Antibody binding leads to platelet sequestration and destruction by mononuclear phagocytes in the spleen and other lymphoid tissues at a rate that exceeds bone marrow production.
*The autoantibodies are often of the IgG class and target platelet membrane glycoproteins.
*Approximately 70% of cases are preceded by a viral illness, suggesting viral sensitization.
What are the typical clinical manifestations of Primary Immune Thrombocytopenia (ITP) in children?
Typical clinical manifestations include:
*Bruising and a generalized petechial rash that often develop acutely 1 to 3 weeks after a viral illness.
*Petechiae can progress to ecchymoses (larger bruises).
*Asymmetric bruising, most commonly on the legs and trunk.
*Possible hemorrhagic bullae of the gums, lips, and other mucous membranes.
*Epistaxis (nose bleeding), which can be severe.
*The child typically appears well, except for the signs of bleeding.
Describe the hemophilias as inherited hemorrhagic diseases. What are the most prevalent types?
Hemophilias are a group of inherited bleeding disorders resulting from mutations in the genes responsible for coagulation factors, specifically factor VIII, factor IX, and factor XI.
The most prevalent types are:
*Hemophilia A (classic hemophilia or factor VIII deficiency), resulting from mutations in the F8 gene.
*Hemophilia B (Christmas disease or factor IX deficiency), resulting from mutations in the F9 gene.
Hemophilias A and B are clinically indistinguishable because factors VIII and IX function together in the coagulation cascade. They are X-linked recessive conditions
How do the hemophilias A and B affect hemostasis, and how do their clinical severities differ?
in hemophilias A and B, alterations or deficiencies of coagulation factors VIII or IX decrease the ability to form blood clots in response to injury, leading to continuous bleeding.
Clinical severity varies based on the concentration of clotting factor in the blood:
*Severe hemophilia (factor level < 1% of normal): Associated with spontaneous bleeding.
*Moderate hemophilia (1% to 5% of normal): Bleeding may occur with injury, trauma, or surgery.
*Mild hemophilia (6% to 50% of normal): Bleeding typically occurs only after severe trauma or surgery.
What is a characteristic type of bleeding seen in individuals with hemophilia?
Joint bleeding, or hemarthrosis, is the most characteristic type of bleeding in hemophilia. The joints most often affected are the knees, ankles, and elbows. Hemarthrosis causes pain, limits joint mobility, and can lead to degenerative joint changes.
Briefly describe von Willebrand disease and its role in hemostasis.
von Willebrand disease is an inherited condition resulting from a deficiency or dysfunction in von Willebrand factor.
von Willebrand factor plays a crucial role in hemostasis by:
*Binding factor VIII (protecting it from degradation).
*Binding platelets to the blood vessel wall during the clotting process.
As a result, factor VIII activity may be decreased in individuals with von Willebrand disease.
