Hematologic System Notes

  • The hematologic system is responsible for the production and regulation of blood cells, encompassing components such as red blood cells, white blood cells, and platelets. Various organs, including the bone marrow, spleen, and liver, play crucial roles in maintaining homeostasis and responding to physiological changes.

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 carbon dioxide (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: 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 B12/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 cells are removed by the liver and spleen.

  • Contain hemoglobin, which carries oxygen to cells and some carbon dioxide (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.

  • Normal range: 5,000 to 10,000.

  • Migrate from bone marrow to areas where 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, leading to a 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.

  • Normal range: 150,000 to 400,000.

  • Low count indicates 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 a reservoir for blood and contracts during hemorrhage to push blood into the cardiovascular system.

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

  • Lymph nodes: Filter out leukocytes.

Changes of 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: 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 actual blood samples.

  • Leukocyte count: Infection/immune disorder.

  • Platelets: Clotting.

  • Hematocrit: Volume of blood cells in relation to the 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 determines 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: Problem Statement/Nursing Diagnosis

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

Nursing Management: Planning

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

Nursing Management: Implementation

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

Nursing Management: 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.

Critical Thinking Question #1

  • An 80-year-old patient with megaloblastic anemia is admitted after a fall that resulted in a fractured hip. In preparing for surgical repair of the hip, a CBC is done. Which of the following is most concerning?

    • Hemoglobin (Hgb) 6

    • Hematocrit (HCT) 17%

    • RBC 2.2 million

    • WBCs 2000 (Most Concerning)

Critical Thinking Question #2

  • A nurse initiates neutropenic precautions for a patient who has undergone chemotherapy. Which nursing action (s) would be considered appropriate? (Select all that apply).

    • Use clean technique for wound care and invasive procedures

    • Use transmission-based isolation precautions as needed

    • Allow all visitors as desired (Incorrect)

    • Maintain integrity of skin and mucosa

    • Provide analgesics as needed