Lecture 8 - Blood Flashcards
What does a CBC measure?
A count of the patients complete blood cells: WBCs, Plts, and RBCs
What colour is the vial that blood is usually collected in for a CBC?
Purple
Erythrocytes have which role?
Transfer oxygen throughout body to deliver to organs and tissues.
What is polycythemia?
Increased RBC count
What is anemia?
Deficiency in the number or volume of RBCs, the quality or quantity of Hb or a combination of factors
What is the normal RBC count?
Female: 4.2-5.4 x 10^12/L
Male: 4.7-6.2 x 10^12/L
Note: The slides say the unit is x1012/L. This is incorrect.
What does Hb measure?
Gas carrying capacity of the RBC
What might cause low Hb?
Low RBC production - such as aplastic anemia
RBC destruction - Sickle cell
Hemodilution, bleeding and dehydration can also reduce Hb.
What are normal lab values for Hb?
Female - 120-160 g/L
Male - 140-180 g/L
What is considered a critical hemoglobin level and must be reported to the provider immediately?
<70 g/L for both sexes
What does Hct measure?
Packed cell volume of RBC as a percentage (% of blood cells compared to total blood volume)
What is the normal hematocrit
Female: 37-47%
Male: 42-54%
What does MCV measure?
Mean corpus volume measures the size of RBCs
What does MCH measure?
Mean corpuscular hemoglobin measures the average weight of Hb/RBC
What does the MCHC measure?
Mean corpuscular hemoglobin concentration measures the concentration of Hbg in the RBC
What does RBC morpholology measure?
Examines the size and shape of RBC
What does reticulocyte count measure?
The number of immature RBCs released from the bone marrow into the blood
What does the WBC differential tell us?
The percentage of each type of leukocyte
What is leukocytosis? What might cause it
Increased WBC (> 10x10^9/L)
–> Infection, extreme stress, leukemia
What is leukopenia? What might cause it?
Decreased WBC (< 4x10^9/L)
–> Autoimmune conditions, immunocompromising medications, sepsis, cancer, HIV/AIDS
What is the normal WBC?
4-10
unit is x10^9/L
What do neutrophils help with? What is their normal range?
Bacterial infections
–> 3.0-5.8 x 10^9/L
What do eosinophils help with? What is their normal range?
Allergy response, asthma, parasites
–> 3.0-5.8 x 10^9/L
What do basophils help with? What is their normal range?
Inflammatory and allergy response
–> 0.01-0.05 x 10^9/L
What do lymphocytes help with? What is their normal range?
Viruses
–> 1.5-3.0 x 10^9/L
What do Monocytes help with? What is their normal range?
Fighting infection
–> 0.3-0.5 x 10^9/L
What is neutropenia and what might cause it?
When the bone marrow does not produce enough neutrophils (count lower than 1x 10^9/L)
–> Caused by leukemia, bone marrow depression - increased risk for sepsis related death
What must we do when a patient has neutropenia?
Reverse Isolation
–> Gown/gloves, minimal contact with family members/friends
What is the normal platelet count range?
150-400x 10^9/L
What is considered thrombocytopenia?
Platelets below 150x 10^9/L
–> Significant risk for hemorrhage
What is thrombocytosis?
Plt above 400 x 10^9/L
–> Increased risk for clotting
What does PT measure? What is the average PT?
Prothrombin time is a measure of how long it takes the blood to clot extrinsically in seconds
Specifically, it measures the effects of factors: I, II, V, VII, X
–> Ave is 11-12.5 seconds
What is INR? What is the average?
The international normalized ratio is a standard system of comparing PTs
–> Ave is 0.9-1.1
What is the target INR for someone on warfarin?
2-3
Why might we choose to use an older anticoagulant like warfarin for someone who is elevated risk for falls or other injuries?
Unlike warfarin, low molecular weight heparins (like apixaban) do not have an antidote that we can administer in emergency situation
The antidote for warfarin is Vit K
What does an elevated INR mean?
Higher INR means higher longer time bleeding - elevated bleed time and longer time taken to form a clot.
What blood type allele is recessive?
O
Why would a bilirubin test be ordered?
TO measure the degrees of RBC hemolysis or the liver’s inability to excrete normal quantities of bilirubin
Why would a Coombs test be ordered? What is a direct and indirect Coombs test?
To differentiate between different kinds of hemolytic anemias, to detect immune antibodies, or to detect Rh factor.
Direct - antibodies attached to RBCS
Indirect - antibodies in serum
Why would an erythropoietin test be ordered?
to measure the degree of hormonal stimulation from the kidneys of the bone marrow released to RBCs
Why would a ferritin test be ordered?
Ferritin is a major iron storage protein, it is usually present in blood in concentrations directly related to iron storage
Why would a folate test be ordered?
Folate is necessary for RBC production