Nursing 280: Pathophysiology Examination

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Nursing 280 PathophysiologyExamination
2Module ISection C Alterations in the
Hematologic System

• Presented by
• Ronda M. Overdiek, M.S.N., R.N.

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Section C Alterations in the Hematologic System

• Comprises
• Chapters 19 20
• Major Areas of Focus
• Normal lab values
• Cellular blood components
• Pathophysiology
• Anemias
• Polycythemia
• Hemostatic Disorders
• Leukocyte/lymphoid function

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Objectives 1-3

• Objective 1 Describe normal lab values which
  reflect condition of an individual hematological
  status erythrocytes, leukocytes, granulocytes
  (neutrophils, eosinophils, basophils)
• Objective 2 Differentiate cellular components
  of blood as to major function Agranulocytes
  (monocytes/macrophages), Lymphocytes, Platelets.
• Objective 3 Discuss growth and destruction of
  blood cells and systematic manifestations

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Function of blood

• Delivery of substances needed for cellular
  metabolisms in tissues
• Defense against invading microorganisms and
  injury
• Maintenance of acid-base balance

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Review Composition of Blood
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Components of Formed Elements
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Formed Elements of Blood Come From

• Hematopoiesis
• Blood cell production
• Occurs in liver/spleen/bone marrow
• Proliferate divide/multiply (mitosis)
• Differentiate Into cellular components
• Altered in pathological states
• Hemorrhage
• Anemia
• Infection

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Stem Cells
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Components of Formed ElementsErythrocytes

• Erythrocytes
• Most abundant cells of the blood
• Responsible for tissue oxygenation
• Lifespan 120 days
• Properties
• Biconcavity/reversible deformability

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Erythrocyte Production
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Hemoglobin

• Oxygen carrying protein of erythrocyte
• Single erythrocyte can contain as many as 300
  hemoglobin molecules
• Hemoglobin protein
• The globins (two pairs)
• The hemes (Iron Protoporphyrin)

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Erythrocyte Destruction

• Life span 120 days
• Age Loss of reversible deformability
• Destroyed by Macrophages
• Spleen
• Liver
• Heme is also destroyed
• Globins broken down to amino acids
• Iron Recycled
• Porphyrin is reduced to bilirubin

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Objective 4Describe normal physiological
effects of anemia

• Anemia
• Reduction in the total number of circulating
  erythrocytes
• Decrease in the quality or quantity of hemoglobin
• Causes
• Altered production of erythrocytes
• Blood loss
• Increased erythrocyte destruction
• Combination of all three

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Progression/Manifestations Of Anemia
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Classifications of Anemia

• Macrocytic-Normochromic (Megaloblastic)
• Defective DNA synthesis resulting in unusually
  large stem cells in the marrow that mature into
  unusually large erythrocytes in the circulation.
  
• Increase in size, thickness, and volume.
• Deficiencies of Vitamin B12/Folate
• Microcytic-Hypochromic
• Small erythrocytes that contain abnormally
  reduced amounts of hemoglobin
• Iron metabolism disorders, porphyrin/heme
  synthesis, globin synthesis
• Normocytic-Normochromic
• Erythrocytes normal in size and Hgb content but
  insufficient in number

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Objective 5 Differentiate major anemias by
etiology, signs/symptoms, treatmentPernicious
Anemia

• Macrocytic-Normochromic (Megaloblastic)
• Most common type
• Caused by Vitamin B12 deficiency due to lack of
  enzyme (IF) required for gastric absorption
• Congenital, gastric mucosal atrophy, chronic
  gastritis (autoimmune disorder), environmental
• Signs/Symptoms weakness, fatigue, loss of
  appetite, abdominal pain, weight loss,
  hepatomegaly, splenomegaly, right-sided heart
  failure.
• Treatment Vitamin B12 replacement (high dose)
• NOT CURABLE, untreated can be fatal

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Iron Deficiency Anemia

• Microcytic-Hypochronic Anemia
• Causes
• Continuous blood loss (ulcers, cirrhosis,
  hemorrhoids, ulcerative colitis, cancer,
  menorrhagia) decreased dietary intake of iron.
• Signs/Symptoms
• Onset s/s gradual, fatigue, weakness, shortness
  of breath, headache, numbness, tingling, memory
  loss, disorientation.
• Evaluation blood tests
• Treatment Identify cause and eliminate, iron
  replacement therapy.

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Aplastic Anemia

• Normocytic-Normochromic
• Caused by bone marrow hypoplasia / aplasia
  (marrow or erythrocyte stem cells are
  underdeveloped, defective, or absent)
• Acquired/Hereditary
• Chemical exposures (arsenic, benzene), HIV,
  hepatitis, drug effects (amphotericin,
  penicillin, dilantin, aspirin, motrin,
  immunosupressant drugs, etc.
• Signs/Symptoms weakness, fatigue, dyspnea, etc.
• Treatment Treat the underlying disorder, blood
  transfusions.

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Hemolytic Anemia

• Normocytic-Normochromic
• Premature accelerated destruction of erythrocytes
• Causes Acquired/Hereditary
• Infection, drugs/toxins, liver disease, kidney
  disease or abnormal immune responses
• Signs/Symptoms Jaundice, splenomegaly,
  hepatomegaly.
• Treatment Remove the cause, splenectomy.

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Sickle Cell

• Abnormal form of hemoglobin
• Stretches the erythrocyte into elongated sickle
  cell shape
• Cause Inherited autosomal recessive
• Signs/Symptoms vascular occlusion, pain, organ
  infarction, fatigue, weakness
• Treatment Supportive care/avoid crisis
• Fever, infection, acidosis, dehydration, exposure
  to cold.
• Blood transfusions
• Genetic Counseling

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Objective 6 Describe the pathogenesis of
polycythemia.

• Two Classifications of Polycythemia
• Relative Dehydration
• Treatment Hydration
• Absolute Primary/Secondary
• Primary
• Polycythemia Vera (Abnormal proliferation of bone
  marrow stem cells)
• Secondary
• Physiologic response resulting from
  erythropoietin secretion caused by hypoxia
• High altitudes/increased levels of CO2, COPD,
  coronary heart failure
• Familial
• Genetic
• Table 20-5, Page 547

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Components of Formed ElementsLeukocytes
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Components of Formed ElementsLeukocytes
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Objective 8 Identify Alterations in Leukocytic
Function

• Function is affected if
• Quantitative
• Too many (leukocytosis) or too few white cells
  (leukopenia)
• Bone marrow dysfunction, premature destruction of
  circulating cells, invasion of infectious
  microorganisms.
• Too many granulocytes (granulocytosis) or too few
  (granulocytopenia)

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Objective 8 Identify Alterations in Leukocytic
Function

• Laboratory Reports
• Shift to the left
• Bands Immature Cells
• Segs Mature Cells
• When bands lt Segs
• Table 20-6 Page 550

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Objective 8 Identify Alterations in Leukocytic
Function

• Qualitative
• Cells are structurally/functionally defective
• Individual cells loose ability to function
• Hematologic defects

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Objective 8 Identify Alterations in Leukocytic
Function

• Infectious Mononucleosis
• Acute infection of B lymphocytes
• Most commonly with Ebstein Barr Virus (EBV)
• S/S include
• Lymphoid tissue swelling, sore throat, fever,
  headache, joint pain, fatigue
• Treatment supportive, analgesics/antipyretics

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Objective 8 Identify Alterations in Leukocytic
Function

• Leukemia
• Clonal malignant disorder of the blood and
  blood-forming organs causing an accumulation of
  dysfunctional cells and loss of cell division
  regulation.
• Uncontrolled proliferation of leukocytes
• Overcrowding of bone marrow
• Decreased production/function of normal
  hematopoietic cells
• Acute/Chronic

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Objective 8 Identify Alterations in Leukocytic
Function

• Acute Leukemia
• Onset abrupt/rapid
• Characterized by undifferentiated/immature cells
  (blast cell)
• Short survival time
• Chronic Leukemia
• Onset is gradual/prolonged clinical course
• Predominant cell is mature but does not function
  normally
• Relatively longer survival time

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Objective 8 Identify Alterations in Leukocytic
Function

• Leukemia
• Cause is unknown
• Genetic predisposition
• Signs/Symptoms
• Fatigue, bleeding, fever, anorexia, wasting of
  muscle, liver/spleen/lymph node enlargement,
  headache, etc.
• Evaluation blood tests/bone marrow
• Treatment Chemotherapy, blood transfusions,
  antibiotics, antifungals, antivirals.

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Objective 9 Identify alterations in lymphoid
function.

• Lymphadenopathy
• Enlarged lymph nodes
• Caused by proliferation of lymphocytes and
  monocytes
• Caused by
• Neoplastic disease
• Immunologic/Inflammatory conditions
• Endocrine Disorders
• Lipid storage Diseases

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Objective 9 Identify alterations in lymphoid
function.

• Hodgkins Lymphoma
• Characterized by presence of Reed-Sternberg cells
• Represent the malignant transformation of cells
• Physical findings
• Adenopathy, mediastinal/abdominal mass,
  splenomegaly.
• Symptoms weight loss, fever, night sweats
• Laboratory Thrombocytosis, leukocytosis,
  eosinophilia.
• Treatment Irradiation/Chemotherapy

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Objective 9 Identify alterations in lymphoid
function.

• Non-Hodgkin Lymphoma
• Malignant transformation of lymphoid system not
  characterized by Reed-Sternberg cells
• Etiology Unknown
• Signs/Symptoms generalized/localized
  lymphadenopathy, back pain, ascites, leg
  swelling.
• Treatment Stem cell transplantation,
  chemotherapy/radiation
• Table 20-12 page 563 (Comparison between Non and
  Hodgkins Lymphoma)

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Components of Formed ElementsPlatelets
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Components of Formed ElementsPlatelets

• Platelets (Thrombocytes)
• Not Cells
• Disc shaped cytoplasmic fragments
• Essential for blood coagulation/control of
  bleeding
• Contain cytoplasmic granules that release
  biochemical mediators when stimulated by injury
  to a blood vessel
• Life span 10 days
• Participate in Hemostasis

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Hemostasis

• Hemostasis-Arrest of bleeding
• Anatomic Components
• Platelets
• Blood Proteins (Clotting Factors)
• Vasculature
• Pathophysiologic processes can result in
  inefficient hemostasis

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Hemostasis

• Sequence of Hemostasis
• Vasoconstriction (vasospasm)
• Formation of platelet plug
• Activation of the coagulation (clotting) cascade
• Formation of a blood clot
• Clot retraction and clot dissolution
  (fibrinolysis)

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Hemostasis Clot Formation

• Clots
• Meshwork of protein strands that stabilize the
  platelet plug
• Strands are made up of fibrin
• Fibrin
• End product of Coagulation Cascade

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Clotting Takes Place
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Retraction/Lysis of Clots

• Fibrin strands shorten (denser/stronger)
• Approximates the edges of the vessel wall
• Seals the sight of the injury
• Lysis
• Fibrinolytic System
• Plasmin
• Splits fibrin and fibrinogen into fibrin
  degradation products

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Objective 7 Hemostatic DisordersHemorrhagic
Diseases

• Hemophilia
• Genetic X-Linked
• Coagulation Factors affected
• Signs/Symptoms
• Abnormal bleeding/bruising
• Evaluation/Treatment
• Laboratory blood tests
• Blood transfusionseducate patients to be careful

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Objective 7 Hemostatic DisordersHemorrhagic
Diseases

• Idiopathic Thrombocytopenia Purpura
• Most common disorder of platelet consumption
• Antiplatelet antibodies bind to plasma membranes
  of platelets, causing sequestration and
  destruction by phagocytes in the spleen/lymphoid
  tissue at a rate that exceeds the ability of the
  bone marrow to produce them.
• Causes 70 Viral (EBV, CMV, Parvo, etc.)
• Signs/Symptoms Bruising, petechial rash,
  epistaxis.
• Evaluation/Treatment Low platelet count, bone
  marrow. Immunosuppressive therapy, splenectomy,
  chemotherapeutic agents.

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Objective 7 Hemostatic DisordersHemorrhagic
Diseases

• Disseminated Intravascular Coagulation (DIC)
• Acquired clinical syndrome occurs because of
  unregulated release of thrombin and subsequent
  fibrin formation and accelerated fibrinolysis.
• Clinical presentation Massive hemorrhage and
  thrombosis to chronic, low-grade condition
• Localized or involve multiple organs
• Clinical conditions that facilitate procoagulant
  activity are
• Arterial hypotension often accompanying shock
• Hypoxemia
• Acidemia
• Stasis of capillary blood flow

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DIC
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Objective 7 Hemostatic DisordersHemorrhagic
Diseases DIC

• Signs/Symptoms
• Acute/Chronic
• Hemorrhaging, petechiae, hematomas, etc. Most
  individual with DIC demonstrate bleeding at three
  unrelated sites and any combination may be
  observed.
• Evaluation/Treatment
• Based on clinical observations/laboratory tests
• Eliminate underlying pathology, restore
  hemostasis, maintain organ function

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Objective 7 Hemostatic DisordersHemorrhagic
Diseases

• Thromboembolic Diseases
• Thrombus clot attaches to the vessel wall
• Composed of fibrin and blood cells (vein/artery)
• Embolus clot that detaches from the vessel wall
  and circulates within the blood
• Clinical Predisposition
• Major surgery (orthopedics), AMI, CHF, limb
  paralysis, spinal injury, postpartum period, bed
  rest for longer than 1 week.

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Objective 7 Hemostatic DisordersHemorrhagic
Diseases

• Thromboembolic Diseases
• Presence of factors that predispose patients to
  thrombus formation
• Injury to blood vessel endothelium
• Abnormalities in blood flow
• Hypercoagulability of blood
• Treatment
• Removal/breakdown of clot

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Why?