RBCs Study Guide Cut

Red blood cells

Erythrocyte

Contain hemoglobin

Oxygen transport

Polycythemia

Excessive proliferation of all blood cells in bone marrow

Less common than anemia

Anemia

Major pathophysiological condition of RBCs

Insufficient oxygen delivery to RBC issue

Increased risk of some forms in certain races/ethnic groups

Hemostasis

Stopping of bleeding

Primary hemostasis

Platelet aggregation

Second hemostasis

Fibrin formation

Produces a clot (thrombus)

Thrombocytopenia

Platelet <100,000 per microliter

Thrombocytosis

Platelet >750,000 per microliter

Erythropoiesis

Synthesis of RBCs

Erythropoietin (EPO)

Released from kidneys

Stimulate RBC formation

What should you do if you see bad symptoms during a transfusion

Stop the transfusion

5 types of anemia

Deficiency

Blood Loss

Hemoglobinopathy

Medications
Hemolysis

Anemia Signs and Symptoms(General)

May be asymptomatic or:

Excessive Fatigue

GI Tract Blood Loss

Heavy menstrual periods (menorrhagia)

Pale complexion

Tachycardia

Jaundice

Splenomegaly

Nutritional Anemias Side Effects

glossitis

cheilitis

koilonychia

pica

Anemia Diagnosis

CBC

PB Smear

Bone marrow aspiration

Echo/electro cardiogram

Nutritional status assessment

Deficiency Anemia Underlying Pathophysiology

Iron, vitamin B12, folic acid deficiency

Adult Total Blood Volume

5 liters

How much blood can be lost without severe side effects?

500 mL

Loss of 1,000 mL or more

• Serious adverse effects

• Hypovolemic shock

• Cerebral hypoperfusion

Symptoms of Blood Loss: under 15%

Orthostatic hypotension and anxiety

Symptoms of Blood Loss: 15%–30%

SNS activity => increased HR

Activation of RAAS

Release of ADH (decrease urine output)

Restlessness and change in consciousness

SARR

SNS=sympathetic nervous system

Symptoms of Blood Loss: 30%–40%

HR >120 bpm

Hypotension

Urine output 5–15 mL/hr

Symptoms of blood loss: over 40%

Severe hypotension

Decreased consciousness

HR >140 bpm

No urine output

2 Types of Blood Loss Anemia

Acute and Chronic

Acute Blood Loss Anemia Causes

trauma, hemorrhage, clotting disorders

Chronic Blood Loss Anemia Causes

• GI bleeding

• Menstrual blood loss

• Medications

What can potentially cause GI bleeding

NSAIDs

Melena

black, tarry, sticky stool, indicative of upper GI bleeding

Hematochezia

bright red or maroon blood in stool, indicative of lower GI bleeding

Hemolytic Anemias(General) underlying pathophysiology

Erythrocyte destruction outpaces replacement

Hemolytic Anemias Causes

Hemoglobinopathies

Autoimmune disorders

Alloimmune hemolysis

Hereditary spherocytosis

Lead poisoning

Hemoglobinopathies

Inherited disorder of Hgb

Autoimmune disorders that can cause hemolytic anemia

Warm (IgG) and cold (IgM) agglutinin syndrome

Alloimmune hemolysis that can cause hemolytic anemia

Blood transfusion reactions

Hemolytic disease of the newborn (HDN)

Hereditary spherocytosis

inherited blood disorder that changes the shape of red blood cells into fragile spheres

Underlying pathophysiology of hemoglobinopathy anemia

Abnormal structure of the Hgb molecule

Cannot carry oxygen efficiently

Leads to destruction of RBC

Hemoglobinopathy anemias types

• Sickle cell anemia

(SCA)

• Thalassemia

Sickle Cell Anemia (SCA)

An autosomal hemoglobinopathy causing abnormal RBC shape

SCA Abnormal Hemoglobin

Hemoglobin S (HbS)

2 genetic forms of HbS

Homozygous and heterozygous forms

Which genetic form of SCA is more severe?

Homozygous

What does the heterozygous HbAS form represent?

Sickle cell trait, or the carrier state.

What happens to RBCs in sickle cell anemia?

They become distorted into a sickle shape in low oxygen conditions

What conditions promote RBC sickling?

Hypoxia, dehydration, and stress

Why don't SCA signs appear immediately after birth?

Fetal hemoglobin initially prevents significant sickling.

SCA and Malaria

SCA provides increased resistance to malaria

Vasco-occlusive crises

Misshaped RBCs lodge in capillaries causing tissue hypoxia

Vasco-occlusive crises effects

Chronic damage to liver, spleen, kidneys, and eyes

Thalassemia

Autosomal recessive hemoglobinopathy

Thalassemia major form

homozygous

Thalassemia minor form

heterozygous

Thalassemia alpha

alpha chain of Hgb affected

Thalassemia beta

beta chain of Hgb affected, most severe

Thalassemia underlying pathophysiology

Reduced globin chain production, causing RBCs to be fragile, small, and poorly hemoglobinized => anemia

Hemolytic disease of the newborn (HDN)

Rh - mother

Rh + fetus

Maternal Rh IgG antibodies cross the placenta and destroy fetal RBCs

Blood transfusion reaction

Recipient antibodies attack incompatible donor RBCs, causing hemolysis

Similarity: HDN vs transfusion reaction

Both involve antibodies attacking RBC antigens, causing hemolysis.

Difference: HDN vs transfusion reaction

HDN: maternal antibodies attack fetal RBCs.

Transfusion: recipient antibodies attack donor RBCs.

Iron Deficiency Anemia Prevalence

Most common anemia worldwide

Etiology of Iron deficiency Anemia

Menorrhagia

GI bleed

Inadequate iron intake

Signs and symptoms of iron deficiency anemia

Typical anemia signs and:
Hair loss anemia

Glossitis

koilonychias(spoon shaped nails)

Pica(craving of ice, clay, starch, dirt)

Pernicious anemia

Autoimmune disease disrupting intrinsic factor

Intrinsic Factor

Specialized protein for absorbing vitamin B12

What is vitamin B12 needed for?

Needed for folic acid metabolism and RBC DNA

How do folic acid deficiency and pernicious anemia differ from Iron deficiency anemia: Main effect

FA and PA: impaired dna synthesis

Iron deficiency: decreased hemoglobin production

How do folic acid deficiency and pernicious anemia differ from Iron deficiency anemia: RBC size

FA and PA: macrolytic

Iron deficiency: microlytic

How do folic acid deficiency and pernicious anemia differ from Iron deficiency anemia: cause

Iron deficiency:Menorrhagia, GI bleed , Inadequate iron intake

PA: autoimmune intrinsic factor effects

Folic acid: poor intake, alcohol, malabsorption

Drugs known to cause hemolytic anemia

Cephalosporins,

quinidine

penicillins

levodopa

methyldopa

NSAIDs

Chemo in general

Reticulocytes clinical concept

Indicator of bone marrow activity

High reticulocyte count indicates elevated RBC formation

Spleen Clinical Concept

“Graveyard of RBCs”

Highly Vascular

Spenomegaly cause

Splenomegaly occurs with large RBC breakdown

Renal failure treatment

EPO used to stimulate RBC production and correct anemia