Hematology Flashcards
What is the most common anemia?
Iron deficiency anemia
How do you know whether someone has anemia?
A reduction in one or more RBC measurements:
- Hemoglobin
- Hematocrit
- RBC count
What is the most common reason why people become anemic?
Blood loss
*Melena, hematemesis, trauma
What are other common reasons why people become anemic
- Sick bone marrow not making enough RBCs
2. RBCs are being destroyed at a rapid rate
Before making a diagnosis of anemia, always ask what question?
Who is my patient? Never presume that anemia in an older patient is due to aging. Although, up to 20% of older patients can have “idiopathic anemia of aging.”
What patients often have lower H&H?
Elderly
What patients often have a higher H&H?
People who live in higher altitudes (Ex. Denver).
*Rationale: oxygen is thin in higher altitudes and body compensates by making extra RBCs. Hematocrit will also be increased. Called polycythemia.
What patients are at risk of polycythemia (excess RBC)?
COPD & smokers because their tissues are chronically deprived of oxygen. When this occurs, as a compensatory mechanism, the body starts to pump out red bed cells resulting in increased numbers of Hgb & Hct.
Testosterone use can also result in polycythemia.
Every anemia is characterized by:
RBC size
RBC color
The suffix referring to cells:
Cytic
Define mico cytic?
Small cells
Define Normo cytic?
Normal-sized cells
Define Macro cytic?
Large cells
What makes a RBC red?
Hemoglobin
Define chromic suffix?
Color
Hypo chromic?
low in color (hgb)
Normo chromic?
normal color (hgb)
Hyper chromic?
too much color (hgb)
On a CBC, what describes the size of a patient’s RBC?
MCV (Mean Corpuscular Volume)
On a CBC, what describes the hemoglobin content of a patient’s RBCs?
MCH (Mean Corpuscular Hemoglobin)
In order to diagnose an anemia, what laboratory test are important to look at ?
MCV & MCH
What is RDW on a CBC?
Red Cell distribution width– variation of size of RBCs is ok but needs to be less than 15%.
Expectation that every red blood cell size should be within 15% of the next one. If the size varies by more than 15%, something is not right.
Remember story about donuts
What is a serum iron level?
How much iron is in circulation in the body.
What is a serum ferritin level?
How much iron is in storage.
Ferritin is a protein that stores iron
What is a reticulocyte count? What are reticulocytes? Where do they come from?
Reticulocyte is an immature RBC. Bone marrow spits out immature RBCs called reticulocytes. It takes about 24 hours for a reticulocyte to go from immature to mature
Why should reticulocytes be counted?
Reveals bone marrows ability to make RBCs when needed.
What lab test could be ordered to help determine whether a patient was taking an iron supplement daily for anemia?
Serum iron
*Rationale – when iron is taken by mouth, serum iron increases. If a patient is taking an iron supplement, the iron level should be high.
What question to always ask before ordering a serum iron level?
Are you taking an iron supplement or a multivitamin with iron.
*Rationale: If patient is taking iron, the serum iron levels will be increased, thus possibly causing a misdiagnosis of anemia.
What is a peripheral (blood) smear?
Drop of blood put on a slide and looked at under a microscope – measure the diameter of RBCs.
What is TIBC?
Total Iron Binding Capacity
Iron count is high = TIBC is low
Iron count is low = TIBC is high
*Iron binds to red blood cells; Iron does not like to swim around in bloodstream and always looking for somewhere to bind too. In an adult who is not deficient in iron, all of their iron binding sites will be full of iron. In an adult with iron deficiency anemia, there are plenty of sites where there is no iron sitting.
- **If there is plenty of iron, the capacity to sit iron is low, because all of the iron binding sites are full.
- **If deficient in iron, the capacity to sit iron is high because there is plenty of places where iron can come and bind.
***Ex. to help remember –> If an egg carton has 12 eggs in it, it’s full of eggs and the capacity to put another egg in it is low. Another carton has no eggs in it so the capacity to put eggs in is high. “Reciprocal relationship”
What is the most common anemia?
Iron deficiency anemia
What kind of anemia is iron deficiency anemia?
Microcytic anemia – small red blood cells
Classified as a microcytic hypo chromic anemia = small, pale cells
What is the most common cause of iron deficiency anemia?
Blood loss
When does a patient become symptomatic when they have iron deficiency anemia?
Most patients are asymptomatic until their H&H drops to about 30 & 10.
What are the classic findings (symptoms) of iron deficiency anemia in a young or middle aged adult?
Dizziness, fatigue, weakness, headache, irritability, exercise tolerance
What are the symptoms of an older adult with iron deficiency anemia?
Worsening of another existing disease
Ex. angina (not enough red cells bringing O2 to the myocardium), worsening dementia
What are the classic labs for iron deficiency anemia and will they be low or high values?
Hgb: low Hct: low Serum Fe: low Serum Ferritin: low MCV: low MCH: low TIBC: HIGH RDW: HIGH >15% (rationale for high RDW: when pt becomes anemic, the bone marrow starts shooting out small red blood cells that mix with the ones that are regular sized)
How do we help someone with iron deficiency anemia?
Get more iron in them
What foods are high in iron?
Organ meats (especially liver) Red meat Dried peas & beans Dark, green, leafy vegetables Whole grains Spinach
For vegetarian: recommend lentil soup or anything above besides meat
What supplements are options to treat iron deficiency anemia?
- Ferrous fumarate 325 mg (106mg elemental iron) (poorly tolerated & rarely given)
- Ferrous sulfate 325 mg (65 mg elemental iron) (given to most patients, except pregnant women; TID daily)
- Ferrous gluconate 325 mg (33 mg elemental iron) (use a lot w/pregnant women b/c it’s well tolerated but have to take about 8-10 pills a day)
How many milligrams of elemental iron should be given a day for iron deficiency anemia?
150-200mg of elemental iron
What are the symptoms to watch for when taking iron?
Constipation, heartburn, nausea
A 24 yr old female has iron deficiency anemia. She’s taking 200mg of elemental iron a day. She asks, “when should I expect to feel better?”
In about 2-4 weeks
Rationale: when given iron, bone marrow starts to shoot out reticulocytes. For 3-10 days, once given iron, she will be in high reticulocyte production. The reticulocytes will mature day by day and an increase in Hgb & Hct will occur in 2-4 weeks. When her H&H goes up, she will begin to feel better.
How long to keep patient on iron supplement?
4-6 months
How much do you expect for HCT & Hgb to go up in a month if pt is taking iron?
Hct: 3 points
Hgb: 1 point
What pts are at risk for IDA?
NSAID users --> (aspirin) highest risk d/t GI bleeds Pregnant women Older adults Alcohol abusers Women w/heavy menses Vegetarians, vegans
How are thalassemia described?
Microcytic, hypo chromic anemia – small/pale red blood cells
-most common genetic disorder in the world
Pts with thalassemia should not be inappropriately exposed to what?
Iron
What differential diagnosis should be included in a patient suspected of thalassemia?
Iron deficiency anemia
Never load a patient up with what when they have thalassemia?
Iron
How do you differentiate between iron deficiency anemia & thalassemia?
IDA: iron measures are out of whack; RDW is not normal
Thalassemia: do not have an iron problem; RDW is normal
What advice should be given to women patients who are diagnosed with thalassemia?
“Do not take iron on your own; someone needs to be monitoring you”… Avoid excessive iron
(Pertains to men as well)
What’s another name for anemia of chronic disease?
Anemia of chronic inflammation
How is anemia of chronic disease described?
Normocytic, normochromic – normal size & color
What do patients with anemia of chronic disease have a problem if their cells are normal size and color?
Because they do not have enough red blood cells
Rationale: Red cells do not live the full life span.
Ex. A diabetic pt who has a blood sugar of 300. Red blood cells have to swim through blood vessels and when the blood is thick & sticky because of glucose being 300, the RBCs have to put in more work to move along. Therefore, the RBC cannot live a normal life. Normal RBC lives 100-120 days. When RBCs are stressed, they only live 2-3 months (60-90 days), dying early. The problem is that the bone marrow can’t keep up with making RBC.
What lab might be elevated in a pt with anemia of chronic disease?
Sed rate d/t inflammation
Rationale: this is a clue to not give iron but to find out what else might be going on with the patient.
What supplement do you not give a patient with anemia of chronic disease?
Iron
Rationale: serum iron may be low but giving iron will not help because iron is low d/t the chronic disease.
How do you treat a patient with anemia of chronic disease?
Get better control of their underlying condition; unless they have an occult malignancy
Ex. Diabetes: A1C is 10; once getting A1C down to 7/6; anemia will go away
When patients have a macrocytic anemia, what do they have?
Vitamin deficiency
What group of people are susceptible to macrocytic anemias?
- Elderly patients –> absorbs less B12 & folate with aging d/t the PH in stomach rising; needs an acidic PH environment to absorb B12 & folate
- Alcoholics
What two vitamins go together?
B12 & folate
-When ordering a B12 level, also order a folate level; those two deficiencies go together
What is B12 responsible for?
- helps RBCs mature
- good nerve health
A 45 year old patient has suspected B12 deficiency. What typical symptoms might he exhibit?
Burning in the hands & feet
Rationale: B12 deficiency causes paresthesia, typically the peripheral nerves
What is the management for B12 deficiency?
B12 Injections
What is the management folate deficiency?
Folic acid by mouth
Rationale: folate is a vitamin but you do not supplement patient with folate but rather folic acid
How long does it take for a patient with B12 & folate deficiency to feel better?
One week
Does a patient with B12 deficiency need lifelong replacement (injections)?
Yes
-after correcting anemia, pt continues to receive monthly injections
Does a patient with folate deficiency need lifelong replacement (supplementation)?
No
-one corrected, pt does not need to continue to take folic acid. However, it is a water soluble vitamin, so people often continue to take it because they cannot become toxic.
What is it called when so many petechiae coalesce?
Purpura
What is petechiae and purpura significant for?
Bleeding
What lab to assess bleeding issues? What specific lab test to look at?
CBC –> low PLT count
What is a low PLT count called?
Thrombocytopenia
What does the PLT count have to be in order to be thrombocytopenia?
PLT count < 150, 000
What can cause a patient to have low PLTs?
- Sick bone marrow not producing enough
- Bone marrow may be producing enough but something else is causing PLTs to die very quickly (ex. Lupus, drug-induced, Leukemia)
When thrombocytopenia is recognized, what do you do next?
Refer to hematology
What is idiopathic thrombocytopenia purpura (ITP)?
Cause is unknown of why pt does not have enough PLTs
If healthy today, the white blood cell that’s present in the greatest quantity?
Neutrophils (60-70%)
What are two other names for neutrophils?
Segs
Polys
If healthy today, the white blood cell that’s present in the second greatest quantity?
Lymphocytes (20-25%)
With CBC interpretation, when poly & lymphs (ex. poly 46.5, lymph 43.1) are close in # together, think what?
Viral
What are the two “1st responder” WBC?
Poly & lymphs – respond within 2 hours
Monocyctes respond when? What does it tell you?
Respond in 24 hours …if monocytes are elevated, pt has been sick for over 24 hours
When do you see an elevated eosinophils?
Allergic Reactions
Parasitic infections
When poly & lymphs are far apart in numbers on a CBC (Ex. poly 81, lymph 2), think?
Bacterial
What are “bands?” (CBC interpretation)
Immature white blood cells
What are immature white cells supposed to be?
Bone marrow until they mature
Why does bone marrow let out immature white cells?
Because it believes there is a bad infection; unaware if viral or bacterial
Rationale: Bands sent to central circulation instead of maturing in bone marrow to help fight infection w/poly, lymph, & monocytes.
Differential on CBC should add up to what percent?
100%
