Module 3 Flashcards
MCV means?
mean cell volume; the average volume of a RBC.
Determines if an anemia is normocytic, microcytic, or macrocytic
MCH means?
mean cell Hb; the average mass of Hb per RBC (Hb per cell – this will change depending on size of RBC – bigger RBC will generally have more Hb).
Determines how much Hb is in a RBC
MCHC
mean cell Hb concentration; the average concentration of Hb in a given volume of packed RBC.
Determines if a RBC is hypochromic, normochromic, or hyperchromic
RDW
red cell distribution width; measure of variation of RBC volume, higher value = more variation in size
Signs and symptoms of anemia
Fatigue/Weakness/Dizzy Pallor SOB/Dyspnea Chest pain/Arrhythmias/Tachycardia Orthostatic hypotension or syncope Cold hands and feet Nail changes Decreased growth and development Neurological S/S (Vitamin B12 deficiency) Mild anemia may only cause S/S during exertion due to compensation
Causes of anemia
1) Loss of RBC’s - blood loss, acute & chronic
2) Decreased or abnormal production of RBC’s – due to deficiency of raw materials (Fe, Folate, B12)
3) Increased destruction of RBC’s - hemolytic anemias (sickle cell, thalassemias, etc.)
Anemia of acute blood loss
- Bleeding
- Trauma, peptic ulcer, hemorrhoids, GI bleed
- Hct (% FORMED ELEMENTS BY VOLUME) is low due to hemodilution-shift of fluid from the interstitial space into circulation to compensate for blood loss
- Normocytic, Normochromic anemia
Production of EPO by the kidneys
- Increased reticulocyte (immature RBC’s) count after 1 week
polycythemia
Excess in RBC in circulation
How are anemias classified by size?
Normocytic
Microcytic
Macrocytic
How are anemias classified by hemoglobin content?
Hyperchromic (really red)
Normochromic (normal red hue)
Hypochromic (pale)
Central Symptoms of anemia
- Fatigue
- Dizziness
- Fainting (in severe anemia)
Blood vessel symptoms of anemia
Low blood pressure
Heart symptoms of anemia
- Palpitations
- Rapid heart rate
- Chest pain (severe anemia)
- Angina (severe anemia)
- Heart attack (severe anemia)
Spleen symptoms of anemia
Enlargement
Intestinal symptoms of anemia
Changed stool color
Muscular symptoms of anemia
Weakness
Respiratory symptoms of anemia
Shortness of breath
Skin symptoms of anemia
- Paleness
- Coldness
- Yellowing
Eye symptoms of anemia
Yellowing
Anemia of chronic blood loss
- Rate of loss exceeds ability to regenerate
- Iron reserves become depleted > iron deficiency occurs
- Occult (slow or hidden) blood loss can take months to cause anemia
- Microcytic, hypochromic anemia
- MCV? MCH?
- Low and Low
Macrocytic/megaloblastic
B12 (Cobalamin)/B9 (Folate) deficiency
Macrocytic, Normochromic anemia what does this mean?
large RBC with a Hb content that corresponds with the RBC’s size
Pernicious anemia – used to be fatal, hence the name
B12 malabsorption/auto-immune destruction of gastric mucosa (specifically parietal cells)
IF deficiency
GI Disorders - Celiac Disease, IBD – anything affecting the ileum of the SI
Drugs may interfere with B12 absorption (metformin)
Diabetic drug
Anemias can be classified either by their pathophysiology or their morphology
Pathophysiology:
1) Increased RBC loss; bleeding
2) Decreased RBC production; lack of nutrients (B12, folate, iron) bone marrow disorder, marrow suppression
3) Increased RBC destruction; inherited and acquired hemolytic anemias
Morphology:
1) Normocytic-normal sized (MCV 80-96)
2) Microcytic-smaller than normal (MCV96)
How to tell whether someone has an anemia?
RBC, HgB, HcT
MCV, MCH, MCHC, RDW help with what?
Determine the cause of an anemia
Increased RDW and normal MCV is associated with what?
Early iron, vitamin B12, or folate deficiency
Acute anemia
- Usually due to hemorrhage or hemolysis
- Hemorrhage is by far most common etiology:
- e.g. GI, GU, Surgical, Trauma, Ruptured Aneurism
- When anemia is acute the body does not have enough time to make the necessary physiological adjustments, and the symptoms are more likely to be pronounced and dramatic
When anemia is severe or acute is onset (e.g. hemorrhage), the initial compensatory mechanism is?
Peripheral blood vessel constriction, diverting blood flow to essential vital organs. Decreased blood flow detected by kidneys activates the renin-angiotensin response, causing salt and water retention in an attempt to increase blood volume.
Normochromic, normocytic anemia (normal MCHC, normal MCV).
These include:
- anemias of chronic disease
- hemolytic anemias (those characterized by accelerated destruction of rbc’s)
- anemia of acute hemorrhage
- aplastic anemias (those characterized by disappearance of rbc precursors from the marrow)
Folate deficiency anemia
A deficiency of folic acid results in megaloblastic anemia with the same characteristics as those of Vitamin B12 deficiency, but neurologic changes do not occur.
Deficiency usually caused by inadequate intake
Folate sources: beans, lentils, asparagus, leafy greens (spinach, collards, kale), fortified foods
Folic acid
Folate deficiency:
- megaloblastic anemia
- fetal neural tube defects (spina bifida)
Signs/SymptomsA deficiency of folic acid results in megaloblastic anemia with the same characteristics as those of Vitamin B12 deficiency, but neurologic changes do not occur.
Folate deficiency:
Signs/symptoms folate deficiency:
Folate deficiency: Megaloblastic anemia, fetal neural tube defects (spina bifida)
Signs/symptoms folate deficiency:
1) Pregnant women may give birth to low birth weight, premature and/or infants with neural tube defects
2) Infants & children may exhibit slow overall growth rate
3) anemia
- other signs: digestive disorders, weakness, sore tongue, headaches, heart palipitations, irritability, forgetfullness, behavioral disorders, ELEVATED LEVEL OF HOMOCYSTEINE (risk factor for cardiovascular disease)
Megaloblastic anemia
Neurologic complications with B12 deficiency ONLY
Spastic and flaccid paralysis
Paresthesias of fingers & feet
Mania and psychosis, memory impairment, irritability, depression, and personality changes
Diagnosis of megaloblastic anemia
MCV=high MCH=high (bigger RBC has more Hb in it) – still normochromic. why? - Low serum B12 - Positive IF antibodies serum - Schilling Test
Iron deficiency anemia
- Dietary lack
- Impaired absorption – celiac disease, chronic diarrhea, low gastric HCl
- Increased requirements - growing infants, children/adolescents, menstruating female, pregnant female
- Chronic blood loss - menorrhagia, espophogeal varices, PUD, UC, Crohn’s, GI cancers, hemorrhoids, parasites
- Microcytic, hypochromic anemia
- MCV=low
- MCH=low
- Fatigue, tachycardia, palpitations, tachypnea
- Pallor
- Koilonychia, angular chelitis, alopecia (hair loss)
- Atrophic changes
- tongue > shiny, red, fissured, due to loss of papillae
- Pica
- Eating disorder
- Craving and eating of non-nutritional substances
Diagnosis of iron deficiency
Decreased:
1) RBC’s, Hb, Hct
2) Ferritin - a protein found within most cells of the body that binds to iron; most of the iron stored in the body is bound to ferritin. Ferritin is found in the liver, spleen, skeletal muscles, and bone marrow. Only a small amount of ferritin is found in the blood.
Increased
1) Total Iron-Binding Capacity (TIBC) - The sum of all iron binding sites on transferrin (molecule which shuttles iron in the blood). Under normal circumstances, about one-third of transferrin iron-binding pockets are filled.
2) More binding sites of transferrin are available if a person is iron deficient
- What would happen to TIBC if a person had a failing liver?
Aplastic anemia
- Bone marrow dysfunction characterized by anemia, leukopenia, thrombocytopenia – a pancytopenia!
- All the cells come from the stem cells in the bone marrow.
