Lecture 8 - Blood Flashcards
1
Q
What does a CBC measure?
A
A count of the patients complete blood cells: WBCs, Plts, and RBCs
2
Q
What colour is the vial that blood is usually collected in for a CBC?
A
Purple
3
Q
Erythrocytes have which role?
A
Transfer oxygen throughout body to deliver to organs and tissues.
4
Q
What is polycythemia?
A
Increased RBC count
5
Q
What is anemia?
A
Deficiency in the number or volume of RBCs, the quality or quantity of Hb or a combination of factors
6
Q
What is the normal RBC count?
A
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.
7
Q
What does Hb measure?
A
Gas carrying capacity of the RBC
8
Q
What might cause low Hb?
A
Low RBC production - such as aplastic anemia
RBC destruction - Sickle cell
Hemodilution, bleeding and dehydration can also reduce Hb.
9
Q
What are normal lab values for Hb?
A
Female - 120-160 g/L
Male - 140-180 g/L
10
Q
What is considered a critical hemoglobin level and must be reported to the provider immediately?
A
<70 g/L for both sexes
11
Q
What does Hct measure?
A
Packed cell volume of RBC as a percentage (% of blood cells compared to total blood volume)
12
Q
What is the normal hematocrit
A
Female: 37-47%
Male: 42-54%
13
Q
What does MCV measure?
A
Mean corpus volume measures the size of RBCs
14
Q
What does MCH measure?
A
Mean corpuscular hemoglobin measures the average weight of Hb/RBC
15
Q
What does the MCHC measure?
A
Mean corpuscular hemoglobin concentration measures the concentration of Hbg in the RBC
16
Q
What does RBC morpholology measure?
A
Examines the size and shape of RBC
17
Q
What does reticulocyte count measure?
A
The number of immature RBCs released from the bone marrow into the blood
18
Q
What does the WBC differential tell us?
A
The percentage of each type of leukocyte
19
Q
What is leukocytosis? What might cause it
A
Increased WBC (> 10x10^9/L)
–> Infection, extreme stress, leukemia
20
Q
What is leukopenia? What might cause it?
A
Decreased WBC (< 4x10^9/L)
–> Autoimmune conditions, immunocompromising medications, sepsis, cancer, HIV/AIDS
21
Q
What is the normal WBC?
A
4-10
unit is x10^9/L
22
Q
What do neutrophils help with? What is their normal range?
A
Bacterial infections
–> 3.0-5.8 x 10^9/L
23
Q
What do eosinophils help with? What is their normal range?
A
Allergy response, asthma, parasites
–> 3.0-5.8 x 10^9/L
24
Q
What do basophils help with? What is their normal range?
A
Inflammatory and allergy response
–> 0.01-0.05 x 10^9/L
25
What do lymphocytes help with? What is their normal range?
Viruses
--> 1.5-3.0 x 10^9/L
26
What do Monocytes help with? What is their normal range?
Fighting infection
--> 0.3-0.5 x 10^9/L
27
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
28
What must we do when a patient has neutropenia?
Reverse Isolation
--> Gown/gloves, minimal contact with family members/friends
29
What is the normal platelet count range?
150-400x 10^9/L
30
What is considered thrombocytopenia?
Platelets below 150x 10^9/L
--> Significant risk for hemorrhage
31
What is thrombocytosis?
Plt above 400 x 10^9/L
--> Increased risk for clotting
32
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
33
What is INR? What is the average?
The international normalized ratio is a standard system of comparing PTs
--> Ave is 0.9-1.1
34
What is the target INR for someone on warfarin?
2-3
35
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
36
What does an elevated INR mean?
Higher INR means higher longer time bleeding - elevated bleed time and longer time taken to form a clot.
37
What blood type allele is recessive?
O
38
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
39
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
40
Why would an erythropoietin test be ordered?
to measure the degree of hormonal stimulation from the kidneys of the bone marrow released to RBCs
41
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
42
Why would a folate test be ordered?
Folate is necessary for RBC production
43
Why would a haptoglobin test be ordered?
Haptoglobin is a serum glycoprotein that binds to HB releases into the bloodstream by hemolysis.
Decreased - RBC hemolysis
Increased - infection, inflammation, cancer
44
Why would an iron test be ordered?
Serum iron is a reflection of the amount of iron combine with proteins in serum and is an accurate indication of status of iron storage and use.
45
What can anemia cause?
Hypoxia
46
How can we diagnose anemia?
CBC, reticulocyte count, peripheral blood smear.
47
Patients are usually asymptomatic of anemia until...
Hemoglobin is below 60.
48
What are some general symptoms of anemia?
--> Pruritis, jaundice
--> Tachy, increased pulse pressure, systolic mumer, MI, tachypnea
--> Bone pain, weight loss
--> Blurred vis, retinal remorrhage
--> Irritability, depression, impaired thought process palpations, headache
49
Usually RBCs are destroyed and lost at the same rate. Decreased erythrocyte production can lead to....
IDA
50
What is the typical lifespan of an RBC?
120 days.
51
What is the most common nutritional deficiency in the world?
IDA
52
What kind of surgeries/illnesses can cause IDA?
GI surgery, gastric bypass, blood loss, peptic ulcers
53
What are the symptoms of IDA?
Often symptoms free, but can be:
--> Pallor, glossitis, cheilitis
54
What are the treatment goals of IDA?
Treat the underlying cause.
55
What medications can treat IDA? What are potential side effects?
Oral iron pills
--> Best taken with vit c for absorption
Notable side effect: Constipation
Mitigate by walking, taking fiber, stool softener as needed, stay hydrated
56
What should you be aware of for a patient taking liquid iron supplement?
It stains teeth, and should be taken with a straw.
57
What are some iron rich foods?
Red meat, beans, eggs, nuts, spinach, oats, whole wheat
58
What are the priorities in acute blood loss (hemorrhage)?
1. Replace blood volume to prevent shock (IV fluids like NS/RL, transfusions)
2. Identify and stop source of the bleed.
59
What are some causes of chronic blood loss? How do we treat it?
Caused by: Hemorrhoids, menstruation, postmenopausal blood loss, ulcers
Stop the bleed if possible, and provide oral iron supplements.
60
What are some causes of anemia?
--> Decreased erythrocyte production
-->IDA
--> Acute or Chronic blood loss
--> Increased erythrocyte destruction: SCD
61
What is sickle cell anemia?
A group on inheritied recessive disorders where hemoglobin S is produced.
Hg S causes RBC stiffens and elongated (sickle shape) when exposed to low oxygen.
These cells can stick together, block vessels and become ischemic, and cause pain crises.
62
What environmental factors can cause a decrease in oxygen that results in cells with Hg S to take on sickle shape?
Changes in altitude, dehydration, infection, cold temperatures, emotional and physical stress, surgery, blood loss.
Sickling episode can also happen without obvious cause.
63
How long do sickle cells survive?
Up to 20 days.
64
What is normal hemoglobin called?
Hemoglobin A
65
Describe what occurs during a sickling crisis?
Low oxygen in blood --> RBCs sickling --> vaso-occusive crisis --> vasospasm further restricts blood flow --> tissue ischemia, infraction, necrosis --> shock (life threatening)
66
What are some symptoms of a sickle cell crisis? What about complications?
Specific to the person, however:
-->Pain, fever, swelling, tenderness, tachypnea, tachy, HTN, N/V
Complications include kidney and liver disease d/t hypoxia
Infection --> treat fever as emergency
67
Which areas of the body are usually most affected by during of a sick cell crisis?
Back, chest, extremities, abd
68
How can we treat sickle cell crisis.
--> O2
--> DVT prophylaxis (anticoagulants)
--> Fluids/electrolytes
Treat pain aggressively with multidisciplinary approach: NSAIDS, local nerve blocks, TENS machine, PCA, acupuncture
69
Should a blood transfusion be used to treat a sickle cell crisis?
No, blood transfusions are not used.
70
What three factors usually manage hemostasis?
Vascular endothelium, platelets, coagulation factors.
71
What are the three major disorders of hemostasis?
1. Thrombocytopenia
2. Hemophilia
3. DIC
72
Platelets below 150 x 10^9/L is considered thrombocytopenia. However, we aren't majorly concerned about hemorrhagic event until...
Platelets are below 50 x 10^9/L
73
What are the three causes of thrombocytopenia?
1. Immune thrombocytopenia purpura (most common)
2. Thrombotic thrombocytopenic purpura
3. Heparin Induced
74
What is immune thrombocytopenia purpura?
Body produces antibodies against the platelets, resulting in abnormal destruction
--> Most common cause of thrombocytopenia
75
What is thrombotic thrombocytopenia purpura?
Aggregation of platelets form microthrombi that form throughout small BVs like arterioles and capillaries. Results in many blood clots forming throughout the body.
--> Rare, idiopathic
76
What is considered heparin induced thrombocytopenia? How long after initiation of treatment is its onset?
Complication of using heparin that occurs 5-10 days after initiation of treatment. Occurs when Plt count drops below 150 x 10^9/L OR when count drops by 50% prior to treatment.
77
What are the symptoms of thrombocytopenia?
Many people are asymptomatic
--> Bleeding, petechiae, hemorrhage
78
What is petechiae?
Small, flat, pinpoint red or brown microhemorrhages
79
How do we diagnose thrombocytopenia?
Test with Plt count
80
A plt transfusion is necessary when plt count it as what level?
less then 10 x 10^9/L
--> Pt is at risk of spontaneous hemorrhage.
81
How can we treat immune thrombocytopenia purpura?
--> Steroids
--> Splenectomy
--> IV Immunoglobulin (WinRho)
--> Tranexamic acid (TXA)
--> Plt transfusion
82
What does tranexamic acid do?
Decreases the speed at which currently existing blood clots break down
83
How can we treat thrombotic thrombocytopenic purpura?
--> Steroids
--> Immunosuppressants
--> Splenectomy
84
How can we treat heparin induced thrombocytopenia?
Stopping the heparin is primary intervention
--> Direct thrombin inhibitor (Argatroban)
--> Indirect thrombin inhibitor (Fondaparinux)
--> Plasmapheresis (exchange)
can switch patient onto Warfarin instead of heparin in later stages to prevent reoccurrence. Only switch once thrombocytopenia has ceased (plts are above 150 x 10^9/L)
85
What gauge needles are needed for blood component infusion?
22-20 G or smaller preferred to push more fluid faster
86
PRBCs requires what specific tubing?
Filtered tubing at 170-260 microns
87
What components are considered blood therapy?
Plts, PRBCs, plasma, albumin
88
What does albumin do? What concentrations is it available in?
Moving water from intravascular to intracellular spaces
--> 5% and 25% solutions
89
What are some indications for albumin administration?
Hypovolemic shock, after large volume paracentesis, liver failure.
90
What is paracentesis?
Draining the peritoneal cavity of fluid in pts wit ascites.
91
What is fresh frozen plasma?
Liquid portion of blood - rich in clotting factors and contains no platelets.
92
What are the indications for fresh frozen plasma administration?
Bleeding related to clotting factor deficiency
--> DIC, hemorrhage, massive transfusion, liver disease, vit K deficiency, excessive warfarin
93
Platelets are prepared from whole blood and often pooled from multiple donors. What are indications for administration?
Bleeding related to thrombocytopenia and platelets lower than 10 x 10^9/L
94
What are the steps to administering blood products?
1. Check your type and cross
2. Ensure order and signed consent
3. Ensure filtered tubing is primed with NS only
4. Obtain double nurse verification and VS before transfusion
5. Start at 50mls per hour for first 15 minutes, then obtain second VS sign
6. If all is well, increase infusion rate to desired rate.
7. Once transfusion is finished you must obtain VS every 30 mins for 1-2 hours.
95
Reactions are most common in the first ___ minutes of administering a blood product?
15
96
What changes in the patient would indicate a reaction to blood product?
--> Temp increase by 1°C (or 38.5°C)
--> Chills, nausea, emesis
--> Back, chest, flank, transfusion site pain
--> Changes in BP
--> Changes in breathing or O2 sats
--> Hash/hives
--> Angioedema
--> Bleeding at site
If noted, immediately stop transfusion and notify provider.
97
With which pt populations should blood not be administered too quickly?
--> Over 70
--> Hx of MI, HF, renal failure
98
Blood is only safe outside of the blood bank for ___ hours
4 hours.
99
What are the different kind of transfusion reactions?
Acute Hemolytic Reactions
Febrile
Allergic
Circulatory Overload
Sepsis
Acute Lung Injury
Massive Blood Transfusions Reaction
100
What is an acute hemolytic reaction?
When there is a mix between type A/B blood types
101
What causes febrile reactions during transfusions?
Incompatibility between leukocytes
--> Risk when more than 5 transfusion has occurred and pt has developed antibodies
102
Who is at risk for circulatory overload during infusions?
Pts with HF, renal failure
--> Infuse over longer time
103
What is a transfusion related acute lung injury?
Sudden development of pulmonary edema
104
When can a massive blood transfusion reaction occur?
When a patient receives a large volume of transfusions in a 24 hours period.
105
What are the symptoms of a delayed transfusion reaction? When does this occur?
Delayed reaction that may include fever, jaundice, delayed hemolysis, decreased Hgb, iron overload, Hep B/C.
--> Occurs 24 hrs - 14 days post transfusion
106
In what situations does iron overload occur as a delayed transfusion reaction?
Pt that receive over 20 units for chronic anemia over.
