Hematology Patho Flashcards
What is anemia?
Deficit of RBCs
Relative anemia?
Normal total RBC mass with increased plasma volume (happens in pregnancy)
Absolute anemia?
Decrease in # of RBCs
Major function of RBCs?
Carry O2
Tissue Hypoxia
- Caused by decreased RBCs and hemoglobin which decreases O2-carrying capacity
- Signs of tissue hypoxia: claudication (muscle), weakness/fatigue, pallor, increased resp rate and depth, dizziness/fainting/lethargy
What are compensatory mechanisms of tissue hypoxia?
- CV: Increased SV, HR, capillary dilation
- Renal: Increased renin-aldosterone response, Increased salt and water retention, Increased ECF
- Increased DPG in cells: increased release of O2 from hemoglobin in tissues
Clinical Manifestations of Mild anemia
- No symptoms
Clinical manifestations of mild to moderate anemia
- Fatigue
- Generalized weakness
- Loss of stamina
- Tachycardia
- Exertional dyspnea
Clinical manifestations of moderate to severe anemia
- Orthostatic and general hypotension
- Vasoconstriction and pallor
- Tachypnea/dyspnea
- Tachycardia/transient murmur, angina pectoris
- Intermittent claudication
- Night cramps in muscles
- Headache, lightheadedness, faintness
- Tinnitus, roaring in ears
Evaluation and Treatment of Anemia
- Evaluation: labs, bone marrow aspiration
- Treatment: erythropoietin, blood transfusions, supplements, rest/O2/fluids
Iron-Deficiency Anemia
- Most common nutritional deficiency in the world and most common cause of anemia
- Microcytic-hypochromic
- Etiology: decreased capacity to absorb iron, increase in physiologic requirement (pregnancy), excessive iron loss (via blood loss), renal issues
- Assessment findings: pica, fatigue, pallor, headaches and lightheadedness
- Treatments: oral admin of iron
Bleeding Disorders
- Vascular disorders: vascular purpura
- Platelet disorders: abnormal quantity or quality of platelets (thrombocytopenia)
- Coagulation disorders: deficiencies of one or more clotting factors (Vitamin K deficiency, inherited, disseminated intravascular coagulation)
Hemostasis?
physiologic process that stops bleeding at the site of injury while maintaining normal blood flow elsewhere
Primary hemostasis?
initial vasospasm at site of injury and formation of platelet flow
- platelets adhere and clump
- 3-7 minute process
Secondary hemostasis?
coagulation (clot formation from fibrin)
- retraction: firming
- 1 hour
Platelets
- Role in primary and secondary hemostasis
- Complex cell fragments with sticky surface receptors
- Can degranulate and trigger clotting cascade
Coagulation Factors
- Plasma proteins produced by liver - cascade
- Circulate in blood
- Partially activated by platelets and by each other
Pathways
- Intrinsic: triggered when blood contacts altered endothelium and degranulation of platelets
- Extrinsic: triggered by tissue damage (trauma)
- Common pathways: Factor X
Bleeding Disorder Assessment
- Pallor
- Jaundice
- Petechia: flat pinpoint purple spots caused by capillary hemorrhage (no blanching)
- Purpura: groups of petechia
- Ecchymosis
- Hemarthrosis: blood in joints
- Hematoma: collection of blood
- Hematuria
- Hematochezia: blood in stool
- Hematemesis
- Epistaxis: blood in nose
- Hemoptysis: blood in sputum
- Menorrhagia: heavy menstrual bleeding
Bleeding Disorders Lab Eval
- CBC w smear: determine if anemia is present and morphology of platelets
- Bleeding time: evaluate platelet and vascular response
- Prothrombin and INR: evaluates extrinsic pathway of coagulation
- Activated partial thromboplastin time: evaluates intrinsic pathway of coagulation
Bleeding Disorders Treatment
- Depends
- Avoid cause
- Steroids
- IVIG
- Factor replacement
- Platelets
- Fresh frozen plasma
Thrombocytopenia
- Common cause of generalized bleeding
- Etiology: decreased production or increased consumption of platelets
- Assessment: petechiae, purpura, decreased platelet counts, bleeding
- Treatment: treat or remove the cause, block the immune response, blood and/or platelet transfusion
Thrombus
- Stationary blood clot formed within a vessel or chamber of the heart
- Can be arterial or venous
- Composed of aggregated platelets, clotting factors, and fibrin that adhere to vessel wall
- Risks-Virchow’s triad: circulatory stasis (immobility), hypercoagulable conditions (pregnancy, cancer, obesity), endothelial/vessel wall injury (trauma, IV, catheter)
DVT
- Presence of thrombus in one of the deep veins (usually in lower extremities)
- Assessment: edema, pain/tenderness, redness, warmth
- Prediction rules, ultrasound, D-dimer
- Treatment: thrombolytic to break down clot, anticoagulants to reduce further clot formation
- Prevention: anticoagulants, SCD/compression stockings, movement, hydration
