Hematologic System Notes


Overview of Anatomy and Physiology of the Hematologic System

  • Functions of blood:

    • Transportation of water, oxygen, nutrients, hormones, enzymes, and medication TO the cells.

    • Transportation of CO2CO_2 and wastes AWAY from the cells.

    • Regulation of fluid volume, electrolytes, acid-base balance/pH, body temperature.

    • Provides clotting factors for hemostasis.

  • Components of blood:

    • Formed elements and plasma

    • Formed elements: erythrocytes, neutrophils, lymphocytes, monocytes, eosinophils, basophils, platelets

    • Plasma: contains proteins (albumin, globulins, fibrinogen), water, salts, dissolved gases, bicarbonate, hormones, glucose, wastes

Functions of Plasma Proteins

  • Albumin:

    • Raises osmotic pressure to keep fluid from leaking into tissue.

  • Alpha and beta globulins:

    • Combine with lipids and drugs to transport them throughout the body.

  • Gamma globulins:

    • Act as antibodies.

  • Fibrinogen:

    • Essential for clotting.

  • Production of blood cells:

    • Erythropoiesis: formation of blood cells from stem cells, occurs in bone marrow.

    • Requires iron, vitamins B12B_{12}/C/E, folic acid, amino acids.

    • Erythropoietin: made by the kidney, prompts erythrocyte production.

Functions of Red Blood Cells (Erythrocytes)

  • Most numerous of blood cells, live about 120 days, old and damaged are removed by liver and spleen.

  • Contain hemoglobin: carries oxygen to cells and some CO2CO_2 from cells.

  • Normal count varies by gender, range is 4.2 million to 6.2 million.

    • Females: 4.2-5.4 million

    • Males: 4.7-6.1 million

  • Every individual has a blood type: A, B, AB, or O.

  • Hemoglobin level varies by gender, range is 12 to 18.

    • Females: 12-16.7

    • Males: 13-18

Functions of White Blood Cells (Leukocytes)

  • First line of defense against microbes, live about 13 to 20 days.

  • Range is 5,000 to 10,000.

  • Migrate from bone marrow to areas they are needed.

  • Granulocytes:

    • Neutrophils, eosinophils, basophils

    • Produced in red bone marrow

  • Agranulocytes:

    • Lymphocytes, monocytes

    • Produced in red bone marrow and lymphatic tissue

Specific White Blood Cells

  • Neutrophils:

    • More than half of WBC count

    • Destroy pathogens through phagocytosis

    • Production stimulated by bacterial infection which leads to higher than normal WBC count.

  • Eosinophils:

    • Detoxify foreign particles

    • Increase in response to allergic reactions/parasitic infections

  • Basophils:

    • Release histamine during allergic reactions and prevent clotting in small blood vessels.

  • Lymphocytes:

    • B cells and T cells

    • B cells become plasma cells and produce immunoglobulins

    • Some T cells become killer T cells

    • Elevated in viral infections

  • Monocytes:

    • Become macrophages/phagocytes to engulf foreign substances and fight infection

Platelets (Thrombocytes)

  • Live about 10 days

  • Produced by bone marrow

  • First line of protection to prevent bleeding by promoting clotting

  • Maintain hemostasis by balancing clotting and dissolving factors

  • Adhere to damaged/uneven surfaces and clump together

  • Range is 150,000 to 400,000

  • When count drops low, there is risk of spontaneous bleeding in skin, kidney, brain, other internal organs

Interaction of the Lymphatic System with the Vascular System

  • Spleen filters blood and produces lymphocytes

  • Acts as reservoir for blood: contracts during hemorrhage and pushes blood into cardiovascular system

  • Functions are taken over by lymphatic system if spleen is removed

  • Lymph nodes filter out leukocytes

Changes in the Hematologic System with Aging

  • Plasma volume decreases, decreasing blood volume

  • Bone marrow becomes infiltrated with fat/fibrotic tissue, function decreases by 50%

  • New cells are produced at a lower rate

  • Alterations in clotting activity

Causes of Hematologic Disorders

  • Hematology is the study of blood, blood components, and blood- forming tissues

  • Genetics: hemophilia, sickle cell disease

  • Accidental trauma/surgery: bleeding/loss of blood

  • Blunt trauma to spleen: massive internal bleeding

  • Chemicals/incorrect transfusions: hemolysis

  • Iatrogenic:

    • Bone marrow suppression

    • Medications that interfere with absorption/use of folic acid, cause leukopenia/thrombocytopenia/agranulocytosis

  • Nutritional deficiencies, bone marrow damage, malignancy

Prevention of Hematologic Disorders

  • Prevention of blood loss during surgery/childbirth, restore blood loss that has occurred

  • Promotion of proper nutrition

  • Education about preventing nutritional anemia

  • Older adults, especially if they live alone, can be at higher risk for nutritional anemia-obtain a thorough nutrition/dietary history

  • Prudent blood transfusion administration

  • Monitor for side effects of medications

Diagnostic Tests and Procedures

  • Most tests are done on the actual blood

  • Leukocyte count: infection/immune disorder

  • Platelets: clotting

  • Hematocrit: volume of blood cells in relation to volume of plasma

    • Females: 37%-47%

    • Males: 42%-52%

  • Complete blood cell count (CBC): diagnose infection (WBC), anemia

    • With differential: counts of specific WBC present

  • Erythrocyte sedimentation rate (ESR):

    • "Sed rate": detects inflammation/infection

  • Blood typing:

    • ABO and Rh testing: determine blood type/presence of antibodies

  • Tests for anemia:

    • Ferritin, reticulocyte count

  • Coagulation tests:

    • Activated partial thromboplastin time (aPTT): 20-25 seconds

    • Prothrombin time (PT): 12-14 seconds

    • International normalized ratio (INR): normal 1-2, therapeutic for prevention/treatment of DVT/PE 2-3

  • D-dimer:

    • Helps diagnose PE/DIC

  • Sickle cell testing:

    • Hemoglobin S

  • Tests for leukemia:

    • Immunophenotyping, flow cytometry

  • Bone marrow aspiration/biopsy

  • Hemoglobin electrophoresis

  • Hemoglobin A1c: monitor diabetes

Nursing Management

  • Assessment/data collection:

    • History:

      • Ask about signs/symptoms

      • Ask about renal disease

    • Physical assessment:

      • Skin:

        • Red/ruddy appearance: polycythemia

        • Jaundice: hemolysis

        • Bruises, petechiae, cyanosis

        • Use natural lighting when possible

      • Mucous membranes:

        • Indicate anemia if pale

        • Bleeding gums, sore/painful gums/tongue, smooth/beefy red tongue

      • Abdomen:

        • Stomach pain, nausea, hiatal hernia, black/tarry stools, coffee-ground emesis, distention

      • Swollen and painful joints:

        • Hemarthrosis: bleeding into the joints

      • Lymph tissue involvement:

        • Swollen lymph nodes in armpits/groin, splenomegaly

      • Mental state:

        • Dizziness, altered mental function, irritability, headache, difficulty concentrating, lack of energy, depression

      • Activity intolerance:

        • Shortness of breath on exertion, tachycardia at rest, severe fatigue, ability to complete ADLs

Nursing Management (Cont.)

  • Problem statement/nursing diagnosis:

    • Altered nutrition, impaired tissue integrity, decreased activity tolerance, risk for injury, risk for infection

  • Planning:

    • Plan care around rest periods, education about nutrition/consult dietician, prevent infection, conserve energy, manage pain, promote comfort

  • Implementation:

    • Gentle handling to prevent injury/bruising/hematomas, prudent skin care, psychosocial support, referrals to support groups

  • Evaluation:

    • How patient is tolerating treatment, status of laboratory values

Common Problems Related to Disorders of the Hematologic System

  • Excessive bleeding:

    • External: apply pressure immediately, dress wound

    • Internal: surgical intervention

    • Arterial blood is bright red, venous blood is dark red

    • Transfusion is indicated if patient has bleeding disorder, transfuse specific product patient is lacking

  • Excessive clotting:

    • Hypercoagulability

    • Monitor circulation

  • Fatigue:

    • Space activities, allow for frequent rest periods

  • Anorexia:

    • Small, frequent meals high in protein, vitamin C, and iron

    • Provide mouth care, odor-free environment, socialization during meals

  • Pain:

    • Cold and heat for joint pain, frequent assessment for those in sickle cell crisis

  • Infection:

    • Bone marrow failure

    • Transplant is usually needed