Notes on Hematologic and Immunologic Dysfunction

Examination and comments from parents:

• History of fatigue and lack of energy, with descriptions indicating a possible systemic issue.

• Food diary showing poor iron sources, identifying meager iron intake from dietary habits, often lacking essential nutrients.

• Symptoms of frequent infections and bleeding suggest an impaired immune response or platelet dysfunction.

• A common term used in describing abnormal CBC is shift to the left, which refers to the presence of immature neutrophils in the peripheral blood from hyperfunction of the bone marrow, as seen during a bacterial infection

Anemia

• Definition: The most common hematologic disorder in childhood,

  • characterized by a significant reduction in the number of red blood cells (RBCs) or hemoglobin (Hgb) levels below the normal threshold, leading to insufficient oxygen transport to tissues.

Causes and Physiology

• Depletion of RBCs or Hgb due to various factors, including nutritional deficiencies, chronic diseases, or genetic conditions.

• The physiological mechanism involves compromised oxygen delivery, which can provoke compensatory mechanisms from the cardiovascular and respiratory systems.

Morphology

• Characteristic changes in RBC size, shape, or color, often observed through peripheral blood smears, can indicate the specific type of anemia present.

Diagnostic Evaluation

• Diagnosis may vary, often defined as Hgb <10 or 11 g/dL, noting that these levels may be inappropriate thresholds for children, who may have different normative values depending on age and gender.

Classification of Anemias

1. Decreased RBC Production:

   • Signs: Pallor, tachycardia, fatigue, shortness of breath, and muscle weakness, among others. This can occur due to nutritional deficits, such as iron, folate, and vitamin B12 deficiencies, or chronic illnesses.

2. Increased RBC Loss:

   • Signs: Pallor, fatigue, cool skin, and late signs include low blood pressure indicative of shock. This can result from conditions such as gastrointestinal bleeding or trauma.

3. Increased RBC Destruction:

   • Signs: Icteric sclera, fatigue, dark urine, splenomegaly, hepatomegaly, and frontal bossing, which can be due to hemolytic anemias.

Nutritional Deficiencies

Important nutrients, including iron, folate, vitamin B12, and copper, are vital for RBC production and function. Deficiencies in any of these can lead to an elevated risk of anemia. Dietary education and supplementation are crucial in prevention strategies, particularly for high-risk groups such as infants and adolescents.

Chronic Diseases

Conditions such as bone marrow failure, aplastic anemia, malignancies, and chronic infections can contribute to anemia, and diagnosis often requires comprehensive evaluation and management to address the underlying pathology.

Hemostasis Disorders

Includes conditions such as hemophilia (inherited blood clotting disorders), Immune Thrombocytopenic Purpura (ITP), and Disseminated Intravascular Coagulation (DIC), each presenting unique management challenges and requiring specialized treatment protocols.

Hemoglobinopathies

Characterized by both intracorpuscular (within the red blood cells) and extracuscular (outside of the red blood cells) defects, these disorders, such as sickle cell anemia and thalassemia, require targeted management approaches.

Consequences of Anemia

• hemodilution

• decreased peripheral resistance

• increased cardiac circulation and turbulence

  • such increases may produce a murmur

  • cardiac failure may ensue

• Cyanosis, which results from an increased quantity of deoxygenated Hgb in arterial blood, is typically not evident

• growth retardation resulting from decreased cellular metabolism, and coexisting anorexia is common

Therapeutic Management of Anemia

• treatment of the underlying cause

  • transfusion after hemorrhage if needed

  • nutritional intervention for deficiency anemias

• supportive care

  • IV fluids to replace intravascular volume

  • oxygen therapy

  • bed rest

Iron Deficiency Anemia

• caused by an inadequate supply of dietary iron

• Preventable with iron-fortified foods, especially beneficial for:

  • Infants, particularly those who are premature, and adolescents undergoing rapid growth phases.

Pathophysiology & Management

• caused by any number of factors

• milk babies

• therapeutic management

  • increase in the amount of iron the child receives

    • ferrous iron with citric acid

    • Take with food

• prognosis is very good

• Nursing care management

  • diet

    • Preterm infants and LBW infants should receive iron supplements at 2 months

    • iron-fortified formula

  • iron supplement

    • 2 divided doses between meals

    • Don’t take with milk

    • liquid preparation can stain teeth, so take with a straw and brush your teeth after

Sickle Cell Anemia

• one of a group of diseases termed hemoglobinopathies

• partial or complete replacement of normal Hgb with abnormal Hgb S

• sickle cell disease includes

  • sickle cell anemia the homozygous form of the disease (HgbSS), in which valine, amino acid is substituted for glutamic acid

  • sickle cell-C disease

  • sickle cell-hemoglobin E disease

  • Sickle cell ischemia disease

• pathophysiology of sickle cell Anemia

  • autosomal recessive disorder

  • AA are carriers (have sickle cell trait)

  • if both parents have the trait, each of their children has a 25% chance of having disease

  • in areas of the world where malaria is common, individuals with sickle cell trait tend to have a survival advantage over those without the trait

Clinical Manifestations

• Obstruction caused by sickled RBCs

• The vascular inflammation

• increased RBC destruction

• abnormal adhesion, entanglement, and meshing of rigid sickle-shaped cells

• local hypoxia

• cellular death

prognosis of sickle cell anemia

• no cure (except possibly bone marrow transplantation

• supportive care/prevention of sickling episodes

• frequent bacterial infections because of immunocompromised

• Bacterial infection: leading cause of death in young kids with sickle cell disease

• usual life span: into the 5th decade

Sickle Cell Crisis

• precipitating factors

  • anything that increases the body’s need for oxygen or alters the transport of oxygen

  • traumas

  • infection, fever

  • physical and emotional stress

  • Increased blood viscosity caused by dehydration

  • hypoxia

• Therapeutic management of SCC

  • treat the medical emergencies of sickle cell crisis

    • rest to minimize energy loss

    • hydration through oral or IV therapy

    • electrolyte replacement

    • analgesia for pain (tend to be undermedicated)

    • blood replacement for anemia

    • antibiotics for infection

    • possible prophylactic antibiotics for 2 months to 5yrs

    • monitoring of reticulocyte count regularly to evaluate bone marrow function

    • Blood transfusion: if given early in the crisis, it may reduce ischemia

Preventative Measures

• educate the family and child

• Seek early intervention for fever

• give penicillin as ordered

• recognize s/s of splenic sequestration

• provide supportive therapies during the crisis

• meet the psychosocial needs of the family

Hemophilia

A hereditary bleeding disorder primarily attributed to deficiencies of coagulation factors necessitates a strong understanding of their implications and management in daily life.

• Inheritable pattern is X-linked recessive

• Identification of a specific factor deficiency allows for definitive treatment

Types of Hemophilia

• Hemophilia A: Deficiency of factor VIII.

  • produced in the liver and is necessary for the formation of thromboplastin in phase 1 of blood coagulation

• Hemophilia B: Deficiency of factor IX.

  • also known as “ Christmas disease.”

• Von Willebrand Disease: Deficiency of von Willebrand factor affecting both platelet function and factor VIII levels.

Diagnostic Evaluation

• history of bleeding episodes

  • Overt prolonged bleeding

  • hemarthrosis (bleeding into joint cavities), especially the knees, ankles, and elbows

  • ecchymosis

• x-linked inheritance

• lab findings

  • low levels of factors VIII or IX, prolonged partial thromboplastin time

  • normal: platelet count, parathromone levels, and fibrinogen levels

Management

• Replace missing clotting factors

  • aggressive replacement therapy with factor concentrate

  • home infusion

• Desmopressin (DDAVP)

  • IV administration or nasal spray

  • causes 2 to 4 times increase in factor VIII activity

  • used for mild hempophilia

• aminocaproic acid

  • prevents clot destruction

Prognosis of hemophilia

• mild to moderate hemophilia: pt lives near-normally lives

• control of symptoms and limiting joint damage improve quality of life

• treatment options

  • gene therapy

  • A working copy of the factor VIII gene is introduced

care management if hemophilia

• prevent bleeding

  • safe environment

  • dental hygiene

• recognize and control bleeding

  • RICE

• prevent the crippling effects of bleeding

  • during bleeding episodes, the joints is elevated and immobilized, and active ROM exercises are usually instituted after the acute phase

• support the family and home care

  • genetic counseling

Epistaxis (Nosebleed)

A common occurrence in childhood, with recurrent episodes potentially indicating underlying conditions such as clotting disorders.

• vascular abnormalities, leukemia, thrombocytopenia, clotting factor deficiency disease (von Willebrand disease and hemophilia)

Care Management

Focuses on calming the child, applying appropriate nasal pressure, and progressing to further evaluation if necessary.

• bleeding usually stops within 10 min after nasal pressure

• have child sit up and lean forward

• evaluate further if bleeding continues

• discourage nose blowing or picking or rubbing nose

HIV/AIDS in Pediatric Patients

The primary mode of transmission is from mother to child or through risky behaviors in adolescence. Understanding the nuances of pediatric HIV is essential for effective management.

• HAART therapy prevents perinatal transmission

• etiology

  • found in blood, semen, vaginal secretions, anal secretions, breast milk

Pathophysiology

The virus principally targets CD4+ T lymphocytes, ultimately leading to a heightened susceptibility to opportunistic infections, emphasizing the need for vigilant monitoring and management.

• manifestations

  • malnutrition, short stature, cardiomyopathy

• diagnosis

  • infants born to HIV+ mom will test positive

  • early testing using RPA

  • CDC classification system

Therapeutic Management

• goal of therapy

  • slow virus growth

  • prevent/treat opportunistic infections

  • nutritional support

  • symptomatic treatment

• antiretroviral drugs

  • NRTI (zidovudine, didanosine, stavudine, lamivudine, abacavir)

  • adefovir

  • protease inhibitors (indinavir, saquinavir, ritonavir, nelfinavir, amprenavir)

  • fusion inhibitors (enfuvirtide

  • Therapy is lifelong