hematology/immunology - 3511 wk 2

Leukocytes

white blood cells responsible for fighting infection.

Erythrocytes

red blood cells that carry oxygen through hemoglobin.

Thrombocytes

platelets that help stop bleeding by forming a platelet plug.

Erythropoietin — EPO

hormone produced by the kidneys that signals the bone marrow to produce red blood cells.

Hemostasis

process of stopping bleeding and forming a blood clot.

Clot Formation Sequence

• Prothrombin is converted to thrombin

• contributes to conversion of fibrinogen into fibrin

• fibrin forms a mesh that creates the clot with platelet assistance.

Plasmin

breaks down blood clots through fibrinolysis.

Fibrinolysis

the process of breaking down a blood clot.

Hematopoiesis

formation of blood cells in the bone marrow from hematopoietic stem cells.

Bone Marrow — Function

spongy tissue inside bones that functions as the body's blood-cell factory.

Bone Marrow — Products

• red blood cells

• white blood cells

• platelets

from hematopoietic stem cells.

Hgb - hemoglobin

• O2 carrying capacity

• low = anemia

• high = polycythemia

• F: 115-155 g/L

• M: 125-170

hematocrit - Hct

• proportion of RBCs in blood

• low = anemia

• high = dehydration

• F: 36-44%

• M: 41-50%

WBC

• low = immunosuppression

• high = infection

• 4-11 x 10*9/L

serum iron

• low = iron-deficiency anemia

• F: 9-30 umol/L

• M: 11-32 umol/L

ferritin

• low = measures iron stores

• F: 11-307 umol/L

• M: 24-336 umol/L

total Iron Binding Capacity - TIBC

• high = iron deficient

• 45-80 umol/L

bone marrow

• blood cell factory

• spongy tissue inside bone

• produces RBCs, WBC, platelets from hematopoietic stem cells

Anemia — Definition

occurs when there are insufficient healthy red blood cells

or

insufficient hemoglobin to carry adequate O2 to tissues.

causes of anemia

• blood loss - surgery, trauma, menstruation

• chemo/immunosuppressants

  • suppresses bone marrow where RBCs are made

• lack of iron, B12

  • iron deficiency anemia

  • pernicious anemia

Anemia — Pathophysiology Sequence

Decreased RBCs → decreased hemoglobin → decreased oxygen delivery → tissue hypoxia.

Anemia — Main Problem

The major physiological problem in anemia is inadequate oxygen delivery to tissues.

target organs effects - anemia

• heart

• brain

• lungs

• skin

• kidneys

Anemia — Target Organ Effect: Heart

• heart to work harder

• tachycardia

• palpitations

• potentially heart failure.

Anemia — Target Organ Effect: Brain

• dizziness

• headache

• confusion.

Anemia — Target Organ Effect: Lungs

• dyspnea - SOB

• increased respiratory rate.

Anemia — Target Organ Effect: Skin

• pallor - eye conjunctiva

• coolness

• dryness.

Anemia — Target Organ Effect: Kidneys

• Increase erythropoietin production as a compensatory response to anemia.

Anemia — Causes: Blood Loss

Blood loss from surgery, trauma, excessive menstruation, or other sources can cause anemia.

Anemia — Causes: Bone Marrow Suppression

Chemotherapy and immunosuppressants can suppress the bone marrow and reduce RBC production.

Anemia — Causes: Nutrient Deficiency

Lack of iron, vitamin B12, and other building blocks can reduce RBC production.

Anemia — Other Causes

Anemia can result from nutrient deficiencies, bone marrow problems, splenomegaly, or blood loss.

Anemia — Chemotherapy and Bone Marrow

Chemotherapy can suppress bone marrow function, reducing production of blood cells.

Anemia — Immunosuppressants and Bone Marrow

Immunosuppressive medications can suppress bone marrow production of blood cells.

Anemia — Diagnostic Tests

• CBC

• iron studies

• reticulocyte count

• peripheral blood smear.

Anemia — CBC

evaluates hemoglobin, hematocrit, RBCs, WBCs, and platelets.

Anemia — Reticulocyte Count

assess whether the bone marrow is producing new RBCs.

Anemia — Peripheral Blood Smear

appearance and characteristics of blood cells.

Anemia — Diagnostic Criteria from Presentation

• non-pregnant females as having anemia = hemoglobin less than 120 g/L or hematocrit is less than 36%,

• males = hemoglobin = less than 130 g/L or hematocrit is less than 41%.

Hemoglobin — Female Normal Range

115–155 g/L.

Hemoglobin — Male Normal Range

125–170 g/L.

Anika Sharma is a 38-year-old office administrator who presents with fatigue, pallor, shortness of breath on exertion, Hgb 82 g/L, HR 102, and RR 20.

cues indication anemia?

• pallor

• tachycardia

• fatigue

• shortness of breath on exertion

• low hemoglobin of 82 g/L.

Anemia — Visual Signs

pallor involving areas such as the conjunctiva and nail beds/skin.

Anemia — Common Symptoms Visual Review

• tiredness

• pale skin

• dizziness or headache

• rapid heartbeat

• cold hands or feet

• shortness of breath

• bleeding problems.

Anemia — Serious Symptoms

• chest pain

• severe shortness of breath

• fainting

• heavy bleeding requiring immediate care.

Most Common type of anemia

Iron-deficiency anemia

iron-deficiency anemia cause/mech

decrease iron = decrease Hgb production

iron-deficiency anemia - key sings/symptoms

• fatigue

• pallor

• spoon nails

pernicious/B12 anemia cause/mech

• cannot absorb Vit B12 = decrease RBC formation

pernicious/B12 anemia - s/s

• glossitis - beefy red tongue

• paresthesia

• memory changes

aplastic anemia - cause/mech

• bone marrow failure = decrease ALL blood cells

  • pt could be on abx/chemo/immunosuppression = bone marrow depression

aplastic anemia - s/s

• infections

• bleeding

• fatigue

hemolytic anemia - cause/mech

• RBC destroyed faster than bone marrow replaces

  • 128 days

hemolytic anemia - s/s

• jaundice

• dark urine

• splenomegaly - clearing waste

sickle anemia - cause/mech

• inherited

• sickle shape RBC= block vessels

sickle anemia - s/s

• pain crisis

• anemia

• organ damage

Iron-Deficiency Anemia — Pathophysiology

decreases hemoglobin production = reducing oxygen-carrying capacity.

Iron-Deficiency Anemia — Causes

• blood loss

  • GI/GU

• decreased iron intake

• increased iron demand, such as during pregnancy

  • increases iron requirements

• gastric bypass

  • alt absorption

• PICA

• older adults

Iron-Deficiency Anemia — Gastric Bypass

altered absorption.

Iron-Deficiency Anemia — Treatment

• oral ferrous sulfate

• vitamin C to improve absorption

• iron-rich diet.

Pernicious Anemia — Definition

vitamin B12 deficiency caused by lack of intrinsic factor, resulting in impaired B12 absorption.

Intrinsic Factor

required for normal vitamin B12 absorption.

Pernicious Anemia — Neurological Manifestations

• tingling

• gait disturbance = findings findings + beefy red tongue

Pernicious Anemia — + tongue?

glossitis = red, smooth, beefy-red tongue.

Vitamin B12 Deficiency — Causes

• dietary deficiency

• malabsorption.

Pernicious Anemia — Treatment

IM vitamin B12 injections, typically lifelong.

B12 deficiency vs pernicious anemia

• B12 = DEFICIENCY

  • lack in the body

  • cause = diet, GI, meds, malabsorption

  • mech = eat too little B12/malabsorption

• pernicious = AUTOIMMUNE

  • immune system attack STOMACH or INTRINSIC FACOTR

    • cannot absorb dietary B12 (no matter how much pt eats)

B12 Dietary Sources

• eggs

• dairy products

• fortified plant milks.

Vegans and B12

need vitamin B12 supplementation because plant-based diets may not provide adequate naturally occurring B12.

Iron-Rich Foods

• lean red meat

• poultry

• fish

• liver

• legumes

• dark leafy greens

• fortified cereals.

Vitamin C and Iron

Vitamin C increases iron absorption and can be obtained from foods such as citrus fruits and tomatoes.

Tea/Coffee and Iron

should be avoided with iron-containing meals because tannins can inhibit iron absorption.

Ferrous Sulfate — Timing

ferrous sulfate (oral iron) approximately 1 hour before meals because an empty stomach increases absorption.

• take with vit C

Ferrous Sulfate — Black Stools

expected effect of oral iron therapy.

Iron and Drug Absorption

interfere with absorption of some medications, so doses may need to be spaced apart depending on the medication.

Iron Dextran

administered IV or IM and may be used in severe cases of iron deficiency.

Vitamin B12 Injection Schedule

• weekly vitamin B12 injections for four weeks

• followed by monthly injections lifelong for pernicious anemia.

Oral B12

used for dietary B12 deficiency but is not adequate treatment for pernicious anemia when intrinsic factor is absent.

Chronic Anemia and Heart Failure

Prolonged anemia = heart to work harder because reduced hemoglobin decreases oxygen delivery = tachycardia, cardiac hypertrophy, and eventually heart failure.

activity tolerance - anemia

• assists with ADLs when Hgb is LOW

• increase activity as Hgb imrpoves

• use FALL PRECAUTIONS - dizzy = risk

aplastic anemia

• bone marrow FAIL = decrease product of ALL blood cells

  • pancytopenia

causes - aplastic anemia

• autoimmune = T cell destroy hematopoietic stem cells

• myelotoxic agents - chemo/radiation

• viral infection = hepatitis, Epstein-Barr, HIV

dx - aplastic anemia

• bone marrow biopsy = fatty marrow replaces red marrow

• CBC = decrease RBC/WBC/platelelets

pancytopenia consequences - aplastic anemia

• decrease RBC = fatigue, pallor, dyspnea

• decreased WBC = infection risk - neutropenia

• decreased platelets = bleeding risk, petechiae, purpura

nursing actions - aplastic anemia

• protective/REVERSE ISOLATION - prevent infection

• AVOID ASA/NSAIDS - increase risk of BLEED

• monitor fever ABOVE 38 - report IMMEDIATELY

treatment - aplastic anemia

• allogeneic bone marrow transplant

• immunosuppressant

• remove my toxic agent

aplastic anemia - bleeding risk assessment

• petechiae - pinpoint bleeding non-blanch

• purpura - non-blanch larger

• result of low platelet levels

• bruising - ecchymosis

patho of aplastic anemia - core mech

• RBC destroy quicker than bone marrow replace

inherited causes of HEMOLYTIC anemia

• sickle cell disease

• G6PD deficiency - hemolysis triggered by oxidants

  • drugs

  • fava beans

• thalassemia - defect in globin chain production

acquired causes - HEMOLYTIC anemia

• incompatible blood transfusions - antigen-antibody rxn

• autoimmune hemolytic anemia

• infections

  • malaria

  • HIV

• mech - prosthetic heart valves

priority - hemolytic anemia

• recognize hemolysis

• confirm with lab findings

• treat cause

signs of hemolysis - hemolytic anemia

• jaundice - increased bilirubin - RBC breakdown

• dark coloured urine - hemoglobinuria

• splenomegaly - spleen clearing debris

• fatigue, pallor, tachycardia

key lab findings - hemolytic anemia

• increase

  • indirect bilirubin

  • lactate dehydrogenase (LDH)

• decrease

  • haptoglobin

management - hemolytic anemia

• treat the cause

  • stop offending agent

  • treat infection

• corticosteroids for AUTOIMMUNE

• splenectomy - if spleen is destroying RBC excessively

Thrombocytopenia — Definition

low platelet count and = increased bleeding risk.

Thrombocytopenia — Platelet Threshold

platelet count below 150 × 10⁹/L.

• 150,000 or less

• 100,000 = major risk

• 50,000 = deadly

Thrombocytopenia — Causes

• immunosuppressants

• liver disease

• hepatitis

• cirrhosis

• immune thrombocytopenic purpura (ITP)

• impaired platelet production

• increased platelet destruction

• HIT = heparin-induce thromobytopneia

HIT — Meaning

heparin-induced thrombocytopenia

• immune rxn to heparin

• onset = 5-10 days

• STOP HEPARIN IMMEDIATELY

bleeding risk assessment - thrombocytopenia

• petechiae

• purpura/ecchymosis

• epistaxis

• gingival bleeding

• blood in urine/stoll

• SEVERE = INTRACRANIAL BLEEDING

safety interventions - thrombocytopenia

• avoid injections/venipuncture

  • Apply pressure for 10 minutes

• NO ASA, NSAIDS, anticoagulants

• fall precautions

  • padding/safe environment

• platelet transfusion if

  • 10-20 × 10*9

  • active bleeding