Anemia Flashcards
What is anemia?
the major pathophysiological condition affecting RBCs; defined as the reduction in the total number of circulating erythrocytes or a decease in the quality or quantity of hemoglobin
what does a CBC do?
measures all RBCs & RBC characteristics
different types of _______ produce different CBC results
anemia
the size and color of RBCs can be defined as?
normocytic
microcytic
microcytic
anisocytic
poilocytic
What does anisocytic mean?
cells vary in size
what does poilosytic mean?
cells varying in shape
what does a mean corpuscular volume (MVC) indicate?
size of RBCs
What does a mean corpuscular hemoglobin (MCH) indicate?
color of RBC
what does a mean corpuscular hemoglobin concentration (MCHC) indicate?
color of RBC
What does hematocrit levels measure?
percentage of blood made up of RBCs
What is the average hematocrit level?
45%
What is the range for hematocrit in males?
45 to 52%
What is the range for hematocrit in females?
37 to 48%
What is hematocrit at in those with anemia?
around 15%
What is hematocrit around in those with polycythemia?
around 65%
What is included in a CBC?
hemoglobin
hematocrit
number of RBCs
reticulocyte count
mean corpuscular volume
mean corpuscular hemoglobin
mean corpuscular hemoglobin concentration
What does reticulocyte count indicate?
bone marrow activity
the dx of anemia cannot be made only looking at the ________ and _________
hemoglobin and hematocrit
What does the reticulocyte count measure?
number of new RBCs in the blood
what does the reticulocyte count tell you?
helps to determine whether the bone marrow is producing new RBCs at an appropriate rate
what does increaased reticulocyte numbers associated with anemia suggest?
accelerated destruction or loss of RBCs
what is a normal reticulocyte count?
appoximately 1% of total RBCs
What can polycythemia vera be described as?
the opposite of anemia
What labs are elevated in polycythemia vera?
H & H
What is an overabundance of RBCs referred to as?
polycythemia vera
Is the cause known in primary polycythemia?
no
What happens in primary polycythemia?
there is hyperproliferation of all blood cells; blood becomes viscouse
What is there an increased risk of in primary polycythemia?
thromboembolism
Is the cause known in secondary polycythemia?
yes
is primary or secondary polycythemia more common?
secondary
What happens in secondary polycythemia?
hyperproliferation of the RBCs in response to chronic blood hypoxia (like in COPD)
about 98% of all cases of polycythemia are related to a mutation in the ____ gene
JAK2
polycythemia causes RBC crowding which may cause an increased risk of ______, ______, & increased risk of _______ due to blood escaping the vessel.
clots; brusing; bleeding
What is one way that polycythemia can be treated?
therapeutic phlebotomy; taking blood out of the body
What lab testing can be done to diagnose anemia?
- CBC
- peripheral blood smear
- iron
- folic acid
- bone marrow aspiration and/or biopsy
- additional test based on type of anemia
- fecal occult blood test
- vitamin B12 levels
What other testing can be done to help diagnose anemia?
- echocardiogram
- electrocardiogram(EEG)
What are the 3 major causes of anemia?
- decreased erythrocyte production
- increased erythrocyte destruction
- blood loss
Can you have more than one cause of anemia?
yes; can have a combination of any of the 3 causes
What are the 4 classic S & S of anemia?
- pallor
- fatigue
- dyspnea on exertion
- dizziness
What are compensatory mechanisms that are manifestations of anemia?
- tachycardia
- palpitations
- vasoconstriction
What are respiratory manifestations of anemia?
- tachypnea
- increased depth
What are other manifestations of anemia?
- increased interstitial fluid into vascular space
- cold hands/feet
- chest pain
how much blood can an adult lose without serious or lasting effects?
500ml
What can happen if blood loss reaches 1000ml or more?
serious adverse effects like hypovolemia shock & cerebral hypoperfusion
What is acute blood loss?
a rapid ;loss of blood as in hemorrhage
What can cause acute blood loss?
- trauma
- childbirth
- rupture of a major blood vessel or organ
in what disorders can severe GI bleeding occur?
- esophageal varices
- penetrating peptic ulcers
What do those with bleeding due to esophageal varices often exhibit?
hematoemesis
What is coffee ground emesis?
blood mixed with stomach acid & mucus in vomit
What is melena?
blood mixed in stool causing dark, tarry stool
What is hematoachezia?
bright red blood in stool
What are the most common causes of anemia due to chronic blood loss?
- peptic ulcers
- Inflammatory bowel disease
- colon cancer
- menorrhagia (heavy or prolonged menstrual cycles)
- chrones
- ulcerative colitis
What is the most common type of anemia?
iron deficiency anemia
in what gender is iron deficiency anemia more common?
females
iron deficiency anemia is _______- ________
microcytic- hypochromic
What are the 8 possible causes of iron deficiency anemia?
- poor dietary intake
- menses
- pregnancy
- ulcerative colitis
- certain medications
- parasitic infections
- neoplasms
- can also occur in lead poisoning
What is the main nutritional element needed for hemoglobin sythesis?
iron
What is iron composed of?
a heme & globin compound
balance is maintained between iron used as __________ and iron placed in ________
hemoglobin; storage
Can iron be recycled?
yes
iron is in ________ demand
constant
How many grams of iron is in the body at all times?
3-4
How much of iron is held in hemoglobin?
60%
how much iron is stored as ferritin in the macrophages, liver, spleen, and bone marrow?
35%
What is the rest of iron found in?
in myoglobin and bound to transferrin
why is there very little free iron?
it it toxic to the cells
What does serum iron test for?
the level of circulating iron in the blood; % saturated
What is TIBC?
total iron binding capacity; percentage of cells that are actually filled with transferrin
What is the normal serum iron level?
25 -45%
What is the serum iron in those with iron deficient anemia?
less than 20%
What is ferritin?
protein for iron stores (like a bank or pantry)
What is happening in iron deficient anemia?
- pt is using more iron than what is being saved so pt needs to go to stores
- iron needs exceed intake & stores are depleted
- there are no stores & daily intake is not adequate to maintain hemoglobin levels
How do iron deficiency anemia symptoms usually come on?
onset of sx are gradual & appear at different times based on the individual
when may some people begin to experience sx?
when hemoglobin is around 7-8 g/dl
What are some manifestations of iron deficiency anemia?
- non-specific sx
- pica
- epithelial tissue damage occurs
- koilonychia
- pallor of conjunctiva
What is koilonychia?
the “spooning” of the nail bed
What do you check to dx iron deficient anemia?
- hemoglobin
- MCV/MCH/MCHC
- bone marrow biopsy/aspirate
serum iron profile - iron
- TIBC
- transferrrin
- ferritin
what lab may be affected initially in iron deficient anemia?
ferritin
What may the MCV, MCH, & MCHC results be in iron deficient anemia?
MCV will be low (less than 80)
MCH/MCHC will also be low
How can you treat iron deficient anemia?
- iron salts: ferrous sulfate, ferrous gluconate
- orange juice to improve absorption
- carbonyl iron: pure elemental iron
- IV iron: dextran
What is the most common oral form of iron used?
ferrous sulfate
How much elemental ron does ferrous sulfate contain?
65mg
What are the side effects of ferrous sulfate?
- nausea
- heartburn
- constipation!
- black/dark green stool
- teeth staining
should you take ferrous sulfate with or without food?
with food
how can you help mitigate teeth staining when taking ferrous sulfate?
dilute in juice or other beverage
drink with straw
rinse mouth afterward
what should you avoid when taking ferrous sulfate?
avoid coffee, tea, soda, and all calcium-containing foods
concurrent administration of ferrous sulfate with antacids or tetracycline (increases/decreases) absorption
decreases
PPl and H2 blockers (decrease/increase) ferrous sulfate absorption
decrease
while slow-release ferrous sulfate is easier on the stomach, it is less effective. Why is that?
the acid in the duodenum protects the iron but the HCO3 from the pancreas can destroy it
What are the two options for IV iron?
- low molecular weight iron dextran
- ferric gluconate
how is IV ferric gluconate administered?
diluted in NNS & infused over 20-60 minutes depending on dose
What is done before a full dose of ferric gluconate is given?
a test dose (over 5 min) to be sure there is no reaction
What can ferric gluconate cause?
can cause prodromal sx & if bad, infusion is stopped & then often resumed
What are indications to receive IV iron?
- abnormal uterine bleeding
- postpartum
- inflammatory bowel disease
- chronic kidney disease
What are adverse effects that may occur with IV iron?
- hypotension
- anaphylaxis (triggered by dextran): less incidence with other forms of IV iron
What is the cause of megaloblastic anemia?
due to impaired DNA synthesis that causes ineffective erythropoiesis
- results in large stem cells that mature into large but fragile erythrocytes
- defective cells dying too early which decreases numbers in the circulation
What are CBC characteristic in megaloblastic anemia?
- anemia
- macrocytic
- normo or hyperchromic
What is megaloblastic anemia usually related to?
deficiencies in vitamin B12 & folic acid
When do megaloblastic anemia sx usually present?
when advanced, megaloblastic anemia has a slow progession
What is pernicious anemia a deficiency in?
vitamin B12
pernicious anemia is ____ if left untreated
fatal
why is pernicious anemia rare in the US?
vitamin B12 comes from animal products, milk & eggs
What is pernicious anemia thought to be?
an autoimmune disorder
What causes pernicious anemia?
- conditions that cause malabsorption of B12
- decreased intake of B12 products (vegans)
- defective gastric secretions of intrinsic factor from parietal cells of the gastric mucousa
- excessive alcohol use
B12 is needed for ____ ______ and nuclear maturity
DNA synthesis
What prevents abnormal fatty acids from affecting neural lipids which could result in myelin breakdown?
B12
Where does B12 come from?
animal sources
What does B12 bind to?
binds to intrinsic factor which is made from parietal cells in the stomach
What is necessary for B12 absorption?
intrinsic factor
Where is B12 released from intrinsic factor and crosses over to the blood stream?
the ileum
What does B12 bind to that takes it to the storage sites?
transcobalamin
What does type A chronic gastritis do?
destroys all cells that produce secretions in the stomach; affects B12 absorption
how do proton pump inhibitors affect vitamin B12?
decrease absorption; decrease in HCL-HCL needed for absorption
What are things that reduce or eliminate B12 absorption?
- anything that affects parietal cells
- autoimmune disorders or genetic changes
-H pylori infections - excessive ETOH
- smoking
- hot tea ingestion
- gastrectomy
- gastric bypass
What are the clinical manifestations of pernicious anemia?
- classic S & S of anemia
- slow development so sx appear in advanced disease
- fatigue; mood swings
- anorexia; weight loss
- hyperbilirubinemia
- hepatosplenomegaly (in severe cases)
What are the neurologic sx with severe anemia (hbg <7)?
- parethesia of hands & fingers
- ataxia
- memory loss
- vision changes
- weakness, clumsiness, & an unsteady gait
- loss of proprioception
how can pernicious anemia be dx?
CBC w diff
- low H & H
- MCV will be >100
- MCHC/ MHC will be normal
vitamin B12 levels
intrinsic factor
antibodies to parietal cells & IF will be found
bone marrow aspiration
How do you tx pernicious anemia?
vitamin B12
oral, if deficiency is not the problem
- prefered route
injection, if deficiency is the problem
- can be SQ, IM, or intranasal
How do you know treatment for pernicious anemia is working?
will know treatment working by rising reticulocyte count and should normalize in 6 weeks
What kind of anemia is caused by folic acid deficiency?
megaloblastic anemia (macrocytic & normochromic)
What is folic acid needed for?
DNA synthesis & red cell maturation (thymine & adenine)
is folic acid or B12 deficiency more common?
folic acid
What does folic acid deficiency lead to?
large ineffective RBC
In what foods is folic acid found?
- vegetables
- fruits
- cereals
- meat (lost in cooking)
How much folic acid is stored in the body?
500-20,000 mcg
How much folic acid is needed per day?
50-100 mcg/day
how quickly does dietary deficiency of folic acid result in anemia?
within a few months
Who are at risk for folic acid deficiency?
- pregnant & lactating women
- alcoholics
- fad diets
- individuals with celiacs or IBS
- those with chronic inflammatory disorders
Why are pregnant/ lactating women at risk for folic acid deficiency?
need increaes 5-10x. folic acid is needed for neural tube development
Why are alcoholics at risk for folic acid deficiency?
interferes with folate metabolism
why are those on fad diets at increased risk for folic acid deficiency?
decrease folate intake
What kind of chronic inflammatory diseases can result in folic acid deficiency?
- rheumatoid arthritis
- tuberculosis
- psoriasis
- bacterial endocarditis
- systemic infections
What are clinical manifestations are seen in megaloblastic anemia related to folic acid?
classic S&S of anemia
no neurologic sx
manifestations r/t malnourishment
- cheilosis
- stomatitis
- burning mouth syndrome
- dysphagia
- flatulence
- GI disturbances
undiagnosed IBD
how is folic acid deficiency diagnosed?
CBC
- changes in indices before hemoglobin
- MCV> 100
- MCHC & MHC normal
folic acid levels will be low
What is required for folic acid to be converted to active form?
B12
What are the two forms of folic acid that can be given?
active
inactive
is active or inactive folic acid more commonly given?
inactive
how can inactive folic acid be given?
folate (oral)
can be PO, IV, SQ, IM
treat with supplementation
What should you be monitoring when treating folic acid deficiency?
hemoglobin & reticulocyte count
What does aplastic anemia result from?
- breakdown in production in bone marrow stem cells that inhibit growth of RBC, WBC, & platelets
- a failure of the marrow to replace the senescent red cells as they are destroyed & leave the circulation
What is the cell size and color like in aplastic anemia?
normal size & normal color
What does aplastic anemia usually present as?
infection or bleeding
Why does aplastic anemia present as infection or bleeding opposed to anemia?
since WBC & platelets have a shorter life span
What is the onset of aplastic anemia usually like?
can be abrupt or gradual
What are causes of aplastic anemia?
- radiation exposure
- chemotherapy: inhibits hematopoiesis
- chemicals: benzene
- viral illness such as hepatitis, mono, HIV
- pregnancy
cytokines suppress normal stem cell development
cause of aplastic anemia is unknown in about _____ of cases
2/3
How is aplastic anemia dx?
CBC shows pancytopenia
WBC count <200: increasing risk for opportunistic infections
RBC: normocytic & normochromic
How do you treat aplastic anemia?
treat the cause
What may be needed to treat aplastic anemia?
BM transplant
immunosuppressive therapy
prophylactic antibiotics
platelet, RBC, or WBC transfusions
What are symptoms of aplastic anemia?
- infection
- present with fatigue, weakness, pallor
- petechiae/purpura
- ecchymosis
- bleeding from body orifices
who are the ideal donors for bone marrow transplants?
siblings
What are the two bone marrow stimulants that can be used to treat aplastic anemia?
filgrastim (Neupogen)
epoetin-alfa (epogen)
How long do bone marrow stimulants take to work?
about a month
What are the 4 ways hemolytic anemia is aquired?
- drug reactions
- infections
- transfusion reactions
- ABO or Rh factor incompatibility of mother or fetus
- autoimmune disease
What is hemolytic anemia cause by?
premature or accelerated destruction of RBCs
What are the inherited forms of hemolytic anemia?
structure deficits
enzyme deficiencies
defects in globin synthesis or stucture
- sickle cell
- thalassemia
How many people are affected by sickle cell in the US?
over 70k
What ethnicities have the highest concentration of sickle cell?
black people, middle eastern people, and Mediterranean people
How many births result in sickle cell?
1: 400-500
What is the cause of sickle cell?
inherited defect of hemoglobin S leads to hemolytic anemia & chronic organ damage
if someone has a defective sickle cell gene from 1 parent what are they considered?
a carrier; they do not have sickle cell
What must happen for someone to have sickle cell anemia?
must inherit the defective gene from both parents
sickle cell usually causes little problem when properly ___________
oxygenated
What happens when oxygen drops in sickle cell?
fluid polymers realign and cause cells to sickle
What does sickle cell depend on?
- hydration
- PH
- oxygenation
What do sickled cells do?
plug the blood vessels; increase the viscosity
What can sickled cells lead to?
- occlusion of the vessels
- pain
- infarction
- pool in the spleen and hemolysis & can infarct vessels in the spleen
Sickling is not always _________ as the other chains are normal and will produce ___________ ___
permanent; hemoglobin A
When do sickled cells return to normal?
after rehydration & oxygenation
What happens if plasma membrane damage occurs in sickle cell?
cell is irreversibly sickled
The higher the number of cells with hgb S the higher the risk for ___________ sickling - up to even __%
irreversible; 30%
do people with the sickle cell trait experience sx?
NO
Are infants affected by sickle cell anemia?
infants are initially okay because the primary component of their hemoglobin is Hgb F. it takes a few months for hbg S to take over
What are the three main crisis’ that result from sickle cell?
vaso-occlusive crisis
sequestration crisis
aplastic crisis
What happens during a vaso-occlusive crisis?
- sickling in microcirculation
- obstruction of blood flow
- creates a log jam; no blood can move through the vessel
what can a vaso-occlusive crisis cause?
severe pain
can lead to CVA or MI
How long can a vaso-occlusive crisis last?
days to weeks
What happens during a sequestration crisis?
- large amounts of blood pool in the liver & spleen
- causes CV collapse as 20% of blood can pool in the liver/spleen
in what age group do sequestration crisis’ occur?
small children
what is an aplastic crisis?
- extreme anemia from decreased RBC count
- sickled RBC only lives for 10-20 days
- compensatory mechanism in place but if dysfunctional aplastic anemia occurs
How is sickle cell dx?
- mandatory screening at birth using electrophoresis which identified the HB F from the hb A and hbS
- mandatory screening in college athletes NCAA regulations
How can you treat sickle cell?
- prevent complications & crisis
- hydroxyurea: produces more hbF & therefore displaces the hbS
- anticoagulants
- decrease inflammatory response
- pain management
