Clinical Evaluation of Anemia Flashcards
What is the definition of anemia?
How is it measured?
It is a decrease in circulating RBC mass measured by Hb or Hct (percentage of blood made up by RBC).
Hct = 3x Hb
What are the 5 ways the body tries to compensate for anemia?
- Increase erythropoietin, RBC production
- Increase 2,3 DPG to release O2 to tissue easier
- shunt blood from periphery to central organs
- Increase CO
- Increase pulmonary respirations
A patient is considered to be anemic if the Hb concentration is more than _____________ below the mean for their age and sex.
2 SD
What are the three basic causes of anemia?
- Decreased RBC production
- Increased RBC destruction/consumption
- Blood loss
Symptoms of anemia can vary depending on what three patient factors?
- age
- CO/respiratory function
- onset of anemia
Rapid onset of anemia from acutre bleeding is __________________ symptomatic than chronic anemia and any given Hb. Why?
Acute is more symptomatic because chronic allows time for compensatory mechanisms
Why might a person with anemia present with:
- pallor
- fatigue and weakness
- palpations, chest pain
- shortness of breath
- Bone abnormalities
- shunting of blood
- tissue hypoxia due to decreased O2 delivery
- Increased CO
- Increased respirations
- Increased marrow to compensate
What six questions asked in the history will help narrow down what the cause of the anemia is ?
- Food intake
- Alcohol
- Duration of the anemia
- Blood loss
- family history
- medications
What three symptoms and signs would you look for in suspected Fe deficient anemia?
- angular cheilosis- dermatitis at mouth corners
- Koilonychia - spoon shaped nails
- Pica - aggressive ice eating, soil eating, etc
What secondary symptom would you notice with a B12 deficient anemia?
Neurological changes due to subacute degeneration of the cord
What 4 symptoms and signs would you look for in suspected hemolytic anemia?
- Jaundice due to increased serum UCB
- Dark urine due to bilirubinuria
- Pigmented gallstones
- skeletal changes-tall skull, high cheekbones
What signs and symptoms can tell you that the anemia may be due to :
- cancer
- infection
- Renal failure
- weight loss, pain, a mass
- fever, sweats, cough, UTI symptoms
- Nausea, fluid retention
What are the three potential causes of decreased RBC production?
- ineffective erythropoiesis/ maturation defects
- Marrow failure (due to chemo/radiation etc)
- Anemia of chronic disease
What is the normal level of reticulocytes in the peripheral blood?
What happens with decreased red cell production anemia?
What happens with blood loss or hemolytic anemia?
0.5-1.5% of the peripheral blood is reticulocytes
In decreased RBC production anemia, reticulocyte counts decrease.
In hemolytic or blood loss anemia, the reticulocyte count increases
What is the most common source of bleeding that causes anemia (specifically in older people)?
What are the 3 ways this can present?
Bleeding of the GI tract in men and post-menopausal women.
- Hematemesis- vomiting blood
- Melena- high GI bleed (stomach, duodenum) that comes out black bc its older
- Hematochezia- low GI bleed because its fresh blood so colon/rectum
What are the things you need to assess on a patient suspected of anemia secondary to blood loss?
- Check acute bleeding with tilt test and orthostatic BP and pulse tests.
- Check on-going bleeding with stool guaiac, gastric lavage, urinanalysis
- Check “other” bleeding like bruises, petichiae
What is the tilt test?
A test to check for acute blood loss.
You take the patients BP and pulse lying down and standing up.
If the BP drops and pulse goes up when they stand, it is a positive tilt test showing acute blood loss
What is the time frame for hemodilution after an acute bleed?
What does this mean for CBCs and smears?
24 hours
Within the first 24 hours of the bleed, the blood will be normocytic and normochromic and Hb levels will be normal (because they are a percentage of blood and whole blood was lost).
What would you see on CBC for early chronic blood loss? Late chronic blood loss?
Early:
Normocytic and normochromic with elevated reticulocytes
Late:
microcytic and hypochromic with reduced reticulocytes due to acquired Fe deficiency
What condition is determined by the presence of :
- Howell-Jolly bodies
- Pappenheimer bodies
- Heinz bodies
- Asplenia
- Asplenia
- clumped Hb in oxidized states (G6PD deficiency)
If you see a microcytic anemia with low reticulocyte count, is the anemia likely due to blood loss, RBC destruction or impaired RBC production?
What are the possible underlying causes?
Low reticulocytes imply it is a problem with RBC production.
- Fe deficiency
- ACD (Fe stored away)- cancer/inflammation
- Thalassemia, Hemoglobinopathy (would have target cells, low RDW and REALLY small cells)
- Sideroblastic anemia (REALLY uncommon)
What test would allow you to differentiate between Fe deficiency and ACD?
In ACD, ferritin will be high, as will hepcidin
In Fe deficiency, ferritin will be low
How do you diagnose a thalassemia?
A sideroblastic anemia?
Thalassemia-
Run Hb electrophoresis. If decreased HbA, and increased HbA2 and HbF this suggests B thalassemia
Sideroblastic anemia-
Bone biopsy to reveal # of sideroblasts in marrow
Describe what you would see in Fe deficient anemia in terms of:
- serum Fe
- Total Fe Binding capacity
- % saturation
- Ferritin
- decrease
- increase
- decrease
- decrease