Alterations of Erythrocyte Function Flashcards
anemia =
a reduction in the total circulating red cell mass or a decrease in the quality or quantity of hemoglobin
too many RBCs is called
polycythemia
normal RBC count; normal HGB
HGB: 12-18g/dL
RBCs: 4.2-6.1 x 10^6 /mcl
Excessive destruction of RBCs caused by two types of hemolysis…
HEREDITARY HEMOLYSIS - sickle cell trait or disease
ACQUIRED HEMOLYSIS :
- immune reaction (blood transfusion)
- infection (malaria, clostridial)
- drugs (quinidine, PCN, methyldopa)
- liver or kidney disease
- toxins (chemical, venoms)
Classifications of anemia include 3 things?
-ETIOLOGIC FACTOR (cause) - ex. iron-deficient
-SIZE:
.Identified by terms that end in -CYTIC
.macrocytic (large), microcytic (small), normocytic (normal)
-HEMOGLOBIN CONTENT
.identified by terms that end in -CHROMIC
.normochromic (normal amount), hypochromic (decreased amount)
RBCs are present in various sizes
ANISOCYTOSIS
RBCs are present in various shapes
POIKILOCYTOSIS
Classic symptoms of anemia?
fatigue, weakness, dyspnea, elevated HR, pallor - remember organ dysfunction can also occur
Normal hgb males; normal hgb females
M = 13-17 F= 12-15
HCT levels M & F?
M - 41-50%
F - 35-46%
characterized by RBCs that are abnormally small and contain reduced amounts of Hgb
microcytic-hypochromic anemias
Most common microcytic-hypochromic anemia worldwide?
iron-deficiency anemia (IDA)
Highest risk for IDA? Associated with what in children? Causes?
Risk: older adults, women, infants, and those living in poverty
Children: cognitive impairment
Causes: inadequate diet, blood loss, chronic parasite infection, metabolic or functional iron deficiency, menorrhagia
Most common PHYSIOLOGIC CAUSE of IDA?
menstruation - normal menstrual flow = 50mL but can vary by 5x
Woman with increased menstrual loss require increased intake _________/day which equals dietary consumption of _______
3-4mg/day which equals dietary consumption of 30-40mg/day
For MEN AND POSTMENOPAUSAL WOMEN, IRON DEFICIENT ANEMIA IS A GOOD INDICATOR of what?
MALIGNANCY
10-17% will be from malignancy
*older age, male, elevated LDH, low ferritin
(LDH indicates tissue damage)
Most common pathophysiologic cause of IDA?
GI bleed
Protein that STORES IRON. Where is it produced? Where is most of it found? Small amounts where?
FERRITIN - produced in the intestines, but found mostly in the liver, spleen, and bone. Small amount circulates in the blood.
What is the MOST SENSITIVE TEST FOR IDA?
ferritin levels
TRANSPORTS IRON IN THE BLOOD
TRANSFERRIN
*delivers iron from absorption centers (duodenum, macrophages) to tissues
How is iron saturation of transferrin measured? Direct or indirect?
TYPICALLY MEASURED INDIRECTLY BY ASSESSING THE TOTAL IRON BINDING CAPACITY (TIBC)
MEASURE OF AVAILABLE TRANSFERRIN THAT IS LEFT UNBOUND TO IRON
WHAT IS CONSIDERED HIGH?
*see slide 12-13
TOTAL IRON BINDING CAPACITY (TIBC)
LOW TRANSFERRIN THAT IS ACTUALLY SATURATED WITH IRON = HIGH TIBC (meaning that not much transferrin is actually saturated)
*THIS MEANS THERE IS MORE CAPACITY TO BIND OR HIGH TOTAL IRON BINDING CAPACITY
In iron deficiency anemia is the ferritin high or low?
What would happen to the total iron binding capacity in iron deficiency?
ferritin is low (classic test for IDA)
TIBC is high or increased b/c the liver produces more transferrin b/c it’s trying to maximize whatever iron is there to be delivered to the tissues that need it.
This means there are more binding sites for iron
Increased transferrin total, but decreased transferrin saturation = high TIBC
Diagnostic manifestations of IDA?
VALUES: MCV, MCH, RDW, FERRITIN, NORMAL SERUM IRON?, TIBC?
Reticulocyte count?
- low MCV = microcytic
- low MCH = hypochromic
- high RDW >15
- Low INITIAL reticulocyte count
- Elevated reticulocyte count once tx and supplementation with iron begins (can be high after tx)
- FERRITIN LOW
- LOW SERUM IRON (NORMAL 50-75MCG/DL)
- TIBC HIGH (MEANING THAT TRANSFERRIN SATURATION IS DECREASED)