Screening 4 Flashcards
polycythemia aka
erythrocytosis
Polycythemia occurs when there are too many
RBCs
In polycythemia, increased concentration of hemoglobin leads to
- increased blood volume
- increased blood viscosity
Increased blood volume and viscosity limits blood’s ability to
flow easily
What are the two forms of polycythemia?
- primary
- secondary
primary polycythemia aka
polycythemia vera
What is primary polycythemia?
rare bone marrow neoplasm
Primary polycythemia and RBC/WBC
- decreased RBC production
- increased # of RBCs
- usu causes excess WBC and platelet production
What happens to blood in the capillaries with polycythemia and what outward sign does this produce?
- viscous blood plugs capillaries
- get “hot bath sign”
Secondary polycythemia results from
decreased oxygen to the tissues
Secondary polycythemia may be due to (environmental)
- living at high altitudes
- smoking
- radiation
- chronic heart/lung disorders
Initial s/s of polycythemia
- usually vague
- watch for increased BP and hematocrit levels
Why are BP and hematocrit levels increased with polycythemia?
due to increased blood viscosity
What are the 2 features of sickle cell anemia?
- hemolytic anemia
- vasoocclusion
What genetic mutation is seen in sickle cell anemia?
RBCs contain an abnormal hemoglobin S
What does abnormal hemoglobin S cause?
- aggregation into long beta chains
- alters shape of cell
When hemoglobin S is exposed to low concentrations of O2, what happens?
develops sickle appearance instead off a biconcave disc
In addition to the shape change seen with sickle cell anemia, what else happens to the RBC? What does this cause?
- RBCs are highly fragile
- leads to serious anemia
What type of disease is sickle cell anemia?
- inherited
- autosomal recessive
sickle cell anemia: autosomal recessive means
both copies of the gene in each cell have mutations
Sickle cell anemia is the most common ________
inherited blood disorder in the US
sickle cell anemia: African Americans
1 in 500
sickle cell anemia: Hispanic Americans
1 in 1000
manifestation of sickle cell anemia is characterized by
- a series of “crises/episodes” of acute manifestations of the disease
- range in severity
sickle cell anemia: recurrent episodes result in
progressive damage to most organs
What medical issues are frequent and severe with pts who have sickle cell anemia?
- CVAs
- cognitive impairment
The hot bath sign causes:
Intolerable itching
Clinical signs of polycythemia are usually vague initially: what are some common things that happen?
- Decreased mental acuity
- Blurred vision
- Headaches
- etc.
With polycythemia, what values should you monitor closely and why?
monitor BP and hematocrit because of increased blood viscosity
