Topic 4: Anemias Foundations Flashcards
What is anemia?
Decrease in the body’s ability to carry oxygen
A reduction below normal in either the RBC count or the Hb concentration
Is the Hb or RBC count usually used to determine if a patient is anemic?
Hemoglobin
What are the symptoms of anemia?
- shortness of breath (dyspnea)
- fatigue
- dizziness
- tachycardia: heart compensates for anemia by increasing contraction to and heart rate
- pale skin: due to decreased oxygenated Hb which is red
What are hemolytic anemias?
Type of anemia where RBCs are being destroyed at an increased rate
Hb is released from the destroyed RBCs and the heme is converted to bilirubin which is yellow
If there’s enough bilirubin, patients sclera, mucous membranes and skin turn yellow = jaundice
What do anemia symptoms depend on?
Certain symptoms don’t necessarily correlate with a particular Hb or hematocrit level
Symptoms largely depend on how quickly the anemia develops as well as the cardiac reserve of the patient
Ex. Athlete wouldn’t have difficulty till Hb is 8 while COPD patient would have issues with a Hb=10 aka cardiac reserve
Ex. A drop in Hb from 14 to 10 over a few hours would cause more symptoms than someone who is chronically at Hb=9
What are the three ways you can get anemic?
- Lose blood
- Make too little blood
- Destroy too much blood
Why does losing blood cause anemia?
Losing blood = takes time for BM to replace RBCs
In this time, RBC in blood will be low = anemia
Eventually your RBC count will go up and anemia will go away as long as your BM is working properly
What causes anemia due to decreased RBC production?
- lack of necessary building blocks like iron or B12
- lack of room in the BM like if the BM is full of malignant cells there’s not enough room for RBCs to grow
What causes anemia due to increased RBC destruction?
A problem within the RBC itself like an abnormal cell membrane or abnormal form of Hb or lack of an enzyme that helps detoxify the cell
All of these shorten RBC lifespan
Other times, RBC destruction comes from outside like antibodies that mark the cell for destruction or strands of fibrin draped across the vessel lumen that rip the RBCs apart as they pass by
What type of anemia is due to blood loss?
Anemia of blood loss!
Just one (:
What types of anemia are due to decreased RBC production?
- Iron deficiency anemia
- Anemia of chronic disease
- Megaloblastic anemia
- Aplastic anemia
- Sideroblastic anemia
What anemias are due to increased RBC destruction?
- Hereditary spherocytosis
- G6PD déficit y
- Sickle cell anemia
- Thalassemia
- Autoimmune hemolytic anemia
- Micro angiopathic hemolytic anemia
What are the groups of anemias based on RBC size?
Size is the RBC feature used when we classify anemias by morphology aka how they look under the microscope
- Anemias with smaller than normal RBC = microcytic
- Anemias with larger than normal RBC = macrocytic
- Anemias with normally sized RBC = normocytic
Why would we want to use size of RBC to categorize anemias?
Because there’s a test in the CBC called the mean cell volume (MCV) that tells you how big on average a patients RBC are
So you can look at the MCV and easily categorize the anemia they could have to narrow down the diagnosis
Which anemias are microcytic?
- Iron-deficiency anemia
- Thalassemia
- Sideroblastic anemia (lead poisoning)
TAILS Thalassemia Anemia of Chronic Disease Iron deficiency anemia Lead poisoning Sideroblastic anemia
