Anemia Flashcards
Define anemia
a reduction in one of the following components of the CBC: Hgb, Hct, RBC count
what is hematocrit?
percent of a sample of whole blood occupied by intact RBCs
What is normal Hgb for men vs. women?
(15.7 +/- 1.7) (13.8 +/- 1.5)
What Hgb is sufficient for people to live off of?
5
What is the reticulocyte count?
reflects rate of RBC production
What are the mean cell volume and RDW used for?
classifies the type of anemia
What is the first lab to respond to Tx of anemia?
reticulocyte count
True or false: symptoms of anemia are less likely if it evolved over a long period of time
TRUE
what are symptoms of anemia?
dyspnea at rest, fatigue, bounding pulses, palpitations
What is sxs onset of anemia dependent on?
compensatory mechanisms, related to O2 delivery and volume (if marked bleeding)
can anemia cause death?
yes, via CKD, malignancy, HF, older adults who are hospitalized
What can cause anemia?
decreased RBC rpoduction, increased RBC destruction, blood loss (MCC)
what is the lifespan of a RBC?
100 days
what are the morphological causes of anemia?
alterations in RBC size (MCV) and reticulocyte response
define macrocytic anemia
MCV >100/fL
Define normocytic anemia
MCV 81-99fL
Define microcytic anemia
MCV <80fL
Causes of microcytic anemia
iron deficiency, anemia of chronic disease
Causes of normocytic anemia
acute blood loss, hemolytic anemia, anemia of chronic disease
Causes of macrocytic anemia
B12 deficiency, folic acid deficiency, drug induced bone marrow toxicity
What is important to ask yourself when evaluating an anemic pt?
are they bleeding? Is there evidence of increased RBC destruction? Is the bone marrow suppressed? Is the pt iron deficient or deficient in folat or B12?
causes of iron deficiency anemia
diet (children, failure to absorb iron salts), increased utilization (pregnancy, adolescent growth), atransferrinemia, failure to utilize (lead poisoning, chronic disease), blood loss
developmental stages of iron deficiency anemia
depletion of iron stores, decreased ferritin, increased transferrin, fall in serum iron, development of normocytic normochromic anemia, development of microcytic hypochromic anemia
What are the lab values of iron deficiency anemia?
everything decreased, TIBC increased
How is iron deficiency anemia treated?
any iron salt, best place is red meat
what is the recommended daily intake of iron?
>200mg of elemental Fe/day
How much Fe is absorbed from iron salts?
5-10%, changes with bodily needs
ADR of iron
nausea, epigastric discomfort, abdominal cramps, constipation, diarrhea, black stool
what is the #1 drug known for poisoning children
iron
Why are sub-therapeutic doses of iron given?
chronic iron toxicity causes hemochromatosis
What is the most common cause of acute iron poisoning?
accidental ingestion in pediatrics
when is IV iron recommended?
pts with documented iron deficiency who are unable to tolerate or absorb oral iron (CKD, malabsorption syndromes, IBD)
IV iron drugs
iron dextran, ferric gluconate complex, iron sucrose, feraheme, injectafer
Which IV iron preparations can be used in CKD?
ferric gluconate complex, iron sucrose
how much elemental iron is in iron dextran?
50mg/ml
How much elemental iron is in ferric gluconate complex?
12.5mg/ml
How much elemental iron is in iron sucrose?
20mg/ml
What are the available dosage forms of vitamin B12?
injection, lozenge, nasal solution, tablet (ER/SL)
What are the available dosage forms of folic acid?
capsule, injection, tablet
How does folic acid work?
folic acid + CH3B12 decrease homocysteine, succinyl CoA and increase DNA
What should always be done first when prescribing iron dextran?
order test dose first and have nurses watch for anaphylaxis
what is needed to transport B12?
intrinsic factor
what labs should be taken in megaloblastic anemia in geriatrics?
serum folate/B12
what does vitamin B12 deficiency cause?
hematopoietic and neurological systems, abnormal DNA replication
What labs should be ordered when suspect B12 deficiency?
serum B12 and serum methylmalonic acid
What is folic acid deficiency linked with?
acute/chronic alcoholism (malnourished)
Where can B12 be supplied from in your diet?
animal byproducts, some legumes
What are some dietary sources of folate?
green vegetables, liver, some fruit - cooking at length can destroy folate
what can low folate cause in pregnancy?
neural tube defects
What IV should be given to alcoholics?
banana bags
ADR of B12 injectables
itching, dizziness, nausea, anaphylaxis
Folic acid ADR
none oral, IV has rare injection site reactions
What do erythropoeisis stimulating agents do?
“Colony stimulating fators”; glycoprotein hormones that regulate the proliferation and differentiation of hematopoietic progenitor cells in the bone marrow
What are the erythropoeisis stimulating agents
epoetin alfa, darbepoetin alfa
where is EPO made?
in the kidneys, release stimulated by hypoxia to increase differentiation of stem cells into RBCs
what are the effects of EPO?
increase RBC production, prevent apoptosis of erythrocytic progentiors, increase RBC viability
Which EPO stimulating agent is long-acting?
darbepoetin alfa
Which EPO drug can be used to treat HIV pts?
epoetin alfa
What is a therapeutic failure of EPO therapy?
no effect after 12 weeks
what is considered a positive reaction to EPO stimulating agents?
1g/dl of Hgb increase
What is always the preparation of EPO stimulating agents in pts on chemo?
IV
What is the target Hgb level of therapy?
10-12 g/dl, could cause HTN, thrombotic events
ADR of EPO stimulating drugs
HA, HTN, fever, nausea, pruritis, injection site reaction
Don’t initiate tx for anemia if Hgb is above…
10
Why is sickle cell anemia not a true anemia?
low Hct, Hgb, elevated reticulocytes
What are the reasons to be concerned with a patient who has sickle cell anemia?
problems in the microvasculature, veno-occlusive damage, organ damage
How are pts with sickle cell anemia treated?
analgesics, abx, blood transfusions, pneumococcal vaccine
What is the most frequent complication in sickle cell disease?
pain - treat with NSAIDs, acetominophen, opioids
How do anti-sickling agents work?
hydroxyurea increases RBC Hgb F levels, reduce polymerization of Hgb S, reduction of deformed RBCs, increases RBC water, alters RBC adhesion to enothelium
ADR of anti-sickling agents?
leukopenia, CNS, dizziness, disorientation, hallucinations, hepatotoxicity, hyperuricemia, dysuria
What labs should be used to monitor pts taking anti-sickling drugs?
renal function, liver function, serum uric acid
what should be done if leukopenia occurs with anti-sickling agents?
rechallange after labs normalize