Patho Exam 2 - Hematology

What is the percentage of blood that is plasma?

55%

What is the percentage of blood that is formed elements?

45%

Process of Hemostasis

Series of events that stop bleeding

Stages of Hemostasis

Primary and secondary hemostasis leading to clot formation and dissolution

Primary hemostasis

Formation of platelet plug to stop bleeding

Secondary hemostasis

Reinforcement of platelet plug with fibrin clot

Platelets

Cell fragments involved in blood clotting

Blood coagulation factors

Proteins in blood plasma that aid in clot formation

Fibrin clot

Insoluble protein mesh that stabilizes the platelet plug

Fibrinolysis

Process of breaking down the fibrin clot

Anemia - Definition

Functional inability of blood to supply tissues with adequate oxygen

Is anemia a disease?

Anemia is an expression of underlying disorder, not a disease

WHO criteria for Anemia

Hb < 13 in men, Hct < 41%; Hb < 12 in women, Hct < 36%

Revised WHO criteria for Anemia in malignancy

Hb < 14 in male, Hb < 12 in female

Complete Blood Count (CBC)

Lab test measuring blood components

Hemoglobin (Hb)

Protein in red blood cells that carries oxygen

Hematocrit (Hct)

Percentage of blood volume occupied by red blood cells

Reticulocyte

Young red blood cell indicating bone marrow activity

Mean corpuscular volume (MCV)

Average size of red blood cells

Mean cell hemoglobin concentration (MCHC)

Hb concentration in red blood cells

How is anemia categorized?

Categorizing anemia based on cell size and Hb content

Mean corpuscular volumes for morphological classification

Microcytic - MCV < 80

Normocytic - 80 < MCV < 100

Macrocytic - MCV > 100

Generalized Symptoms of Anemia

Pallor

Dizziness

Leg Cramps

Headache

Insomnia

Oxygen deficit - Fatigue, tachycardia, SoB, decreased epithelial cell regeneration

Concentrating (difficulty)

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Types of Anemia

macrocytic-normochromic

microcytic-hypochromic

normocytic-normochromic

Macrocytic Normochromic Anemia

Characterized by large stem cells and defective DNA synthesis. RNA processes at the normal rate

Macrocytic Anemia - Pernicious Anemia

Autoimmune condition causing B12 deficiency due to lack of intrinsic factor with neurological symptoms.

symptoms of pernicious anemia

Symptoms of anemia plus:

Paresthesia

Wobbly gait and difficulty walking

Sore tongue - smooth and beefy

"Lemon yellow" skin (sallow) - a combination of pallor and jaundice (icterus)

Dementia

Macrocytic Anemia - Non-autoimmune

Lack of intrinsic factor due to things like a gastric bypass.

Macrocytic Anemia - Folate Deficiency

Anemia due to inadequate folate absorption, common in alcoholics

Macrocytic Anemia - Diagnosis

Tests like antibodies against parietal cells and methylmalonic acid levels & homocysteine levels.

Macrocytic Anemia - Treatment

Lifelong B12 treatment for pernicious anemia, oral B12 for non-pernicious., take folic acid with B12

Folic acid supplements for folate deficiency

Folate deficiency

Condition characterized by a lack of folate in the body

examples: Crohn's Disease and Celiac (malabsorption/malnutrition)

Microcytic Hypochromic Anemia

Anemia characterized by abnormally small red blood cells with reduced hemoglobin

Iron deficiency - most common worldwide

Leading cause of anemia globally

Clinical presentation of iron deficiency anemia

weakness, fatigue, lightheadedness

PICA, SoB, pale ear lobes, palms, and conjunctiva

HgB decreased to 7 or 8 per dL

Progression of iron deficiency anemia

Koilonychia

Cheilosis, stomatitis, painful ulcerations in the mouth

Dysphagia

Evaluation of Iron deficiency anemia

Hemoglobin - decreased

Hematocrit - decreased

MCV - decreased

Serum ferritin - low

Serum iron / transferrin = iron saturation - low

peripheral blood smear

Bone marrow iron stain (Prussian blue/very invasive)

treatment for iron deficiency anemia

Iron replacement (ferrous sulfate) via PO, IM, or IV

Vitamin C to aid in absorption of iron

Side effects: constipation, black stool

Koilonychia

Clinical sign of iron deficiency anemia, where nails become brittle, thin, and spoon-shaped

Normocytic Normochromic Anemia

Anemia resulting from decreased erythropoiesis with normal cell size and hemoglobin content

Normo Normo etiology

Hemolysis - sickle cell disease, immune, transfusion (decreased RBC lifespan)

acute blood loss

bone marrow suppression - myeloma

anemia of inflammation or chronic disease

hypothyroidism

Anemia of Inflammation

Anemia associated with chronic inflammatory conditions, characterized by altered iron metabolism

Pathogenesis of anemia of inflammation

1. shortened RBC lifespan

2. suppressed EPO production

3. Ineffective bone marrow response

4. altered iron metabolism in macrophages

Anemia of inflammation initially is normocytic normochromic then becomes what?

Microcytic-hypochromic

Hemorrhage

Extravasation of blood from blood vessels

Hematoma

Accumulation of blood within tissues or externally

Can be benign or fatal (retroperitoneal hematoma)

Petechia

Tiny (1-2 mm) red or purple spots on the skin caused by minor bleeding

Purpura

Medium (3mm-1cm) red-purple skin lesion due to blood in tissues from breaks in blood vessels

Ecchymoses

Larger (1-2 cm) purplish patches on the skin caused by bleeding under the skin

Platelet Dysfunction

Impaired function of platelets leading to increased bleeding tendency

von Willebrand Disease

Most common inherited bleeding disorder characterized by a deficiency in von Willebrand factor.

Autosomal Dominant

vWF facilitates platelet adhesion -> causes mild or moderate bleeding

Coagulation Cascade Dysfunction

Impaired blood clotting process often due to factors like vitamin K deficiency or hemophilia

What can cause a vitamin K deficiency?

Antibiotic therapy and malabsorption

Hemophilia A and Hemophilia B characteristics

A - deficient in Factor VIII

B - deficient in Factor IX

X-linked recessive

prolonged bleeding time after minor tissue trauma

Possible hematuria and blood in feces

Diagnostics for hemophilia

Bleeding time and PT normal

PTT, aPTT, coagulation time prolonged

Serum levels for factor VIII are low

Diagnostic tests for bleeding disorders

•Prothrombin time (PT)

•International normalized ratio (INR)

•Activated partial thromboplastin time (aPTT)

•Bleeding time

•Thrombin time

•Complete blood cell count (CBC) with platelet count

•Peripheral blood smear

Disseminated Intravascular Coagulation (DIC)

Complex disorder where both clotting and bleeding occur simultaneously, often triggered by severe infections

Endothelial damage

Injury to the endothelial cells lining blood vessels that can initiate DIC

Consumptive coagulopathy

Condition where blood clotting factors are excessively consumed, leading to abnormal bleeding

Gram-negative bacteria

Type of bacteria with a distinct cell wall structure that can cause severe infections

Most common cause of disseminated intravascular coagulopathy (DIC)