L68-72 Flashcards
1
Q
Compliance = ?
A
Change in V/Change in P
2
Q
When is compliance increased?
A
Loss of elastic recoil (emphysema)
3
Q
When is compliance decreased?
A
Increased elastic recoil (pulmonary fibrosis)
4
Q
Why is there no blood flow through zone 1 of the lungs normally?
A
Alveolar pressure»_space; arteriole and venous pressures
5
Q
What happens to minute ventilation and PaCO2 during exercise?
A
Minute ventilation increases
PaCO2 is normal
6
Q
What happens to minute ventilation and PaCO2 during a panic attack?
A
Minute ventilation increases
PaCO2 decreases
7
Q
What happens to minute ventilation and PaCO2 with increased dead space and intact CNS?
A
Minute ventilation increases
PaCO2 is normal
8
Q
What happens to minute ventilation and PaCO2 with increased dead space but without an intact CNS?
A
Minute ventilation is normal
PaCO2 is increased
9
Q
What happens to minute ventilation and PaCO2 with PE?
A
Minute ventilation is increased
PaCO2 is decreased
10
Q
What is PaO2?
A
Partial pressure of oxygen in the veins
11
Q
What is SaO2?
A
Saturation of Hgb - how much of your available Hb sites around bound to oxygen?
12
Q
What is CaO2?
A
Content of O2 in the blood - how much oxygen is contained per dL of blood?
13
Q
What is DaO2?
A
Delivery of O2 - how much O2 is delivered to the periphery?
14
Q
What is saturation at PO2 of 40? 60?
A
75%
90%
15
Q
What happens to PaO2, SpO2, CaO2, and DaO2 in lung disease?
A
All are low
16
Q
What happens to PaO2, SpO2, CaO2, and DaO2 at altitude?
A
All are low
17
Q
What happens to PaO2, SpO2, CaO2, and DaO2 in CO poisoning?
A
All BUT PaO2 are low
SpO2 is normal by pulse ox
18
Q
What happens to PaO2, SpO2, CaO2, and DaO2 in anemia?
A
PaO2 and SpO2 are normal; CaO2 and DaO2 are low
19
Q
What happens to PaO2, SpO2, CaO2, and DaO2 in cardiomyopathy?
A
All but DaO2 (low) are normal
20
Q
A-a gradient = ?
A
P(alv)O2 - PaO2
21
Q
P(alv)O2 = ?
A
[(P(B) - P(H2O)) x FiO2] - (PaCO2/RQ)
22
Q
What is a normal PmvCO2 and PmvO2?
A
PmvCO2: 45 mmHg
PmvO2: 40 mmHg
23
Q
What is a normal PaCO2 and PaO2?
A
PaCO2: 40 mmHg
PaO2: 95 mmHg
24
Q
What is a normal A-a gradient?
A
(Age/4) + 4
25
What happens to A-a gradient in most diseases?
Increases (but not with altitude, decreased FiO2, or hypercapnea)
26
What is the barometric pressure at 15,000 feet?
450 mmHg
27
What causes the Oxy-Hgb dissociation curve to shift right?
Increased temperature
Increased 2-3 DPG
Decreased pH
(Decreases affinity)
28
What is VQ mismatch?
Decreased V relative to Q
29
What is Shunt?
No O2 reaches capillaries
30
Diffusion-perfusion impairment is occasionally seen in ___.
Cirrhosis
31
What is the first stage of RBC released from the marrow into peripheral blood?
Reticulocyte
32
What is the normal life-span of RBCs?
120 days
33
What is the unique structure of the RBC membrane and what are its components?
Membrane skeleton; spectrin fibers + ankyrin
34
Heme consists of four ___ groups joined into a large ring with a ___ ion incorporated into the center.
Pyrrole; ferrous
35
Two ___ dimers form hemoglobin.
Globin
36
How are RBCs catabolized?
Removed by mononuclear phagocytic engulfment in the spleen
Heme is divided into iron (recycled) and porphyrin (bilirubin) and globin is dismantled into amino acids
37
What are 3 ways to categorize anemia (according to lecture)?
1. Blood loss (acute vs. chronic)
2. Increased rate of destruction (hemolytic anemias)
3. Impaired red cell production (diminished erythropoiesis)
38
How are hemolytic anemias further categorized?
Intrinsic vs. extrinsic abnormalities of RBCs
39
How can intrinsic abnormalities of RBCs be further categorized?
Hereditary vs. acquired
40
How can hereditary intrinsic abnormalities of RBCs in hemolytic anemia be further categorized?
1. Red cell membrane disorders
2. Red cell enzyme deficiencies
3. Disorders of hemoglobin synthesis (structural abnormality vs. deficient globin synthesis)
41
What are the extrinsic abnormalities of RBCs in hemolytic anemia?
1. Ab mediated
2. Mechanical trauma
3. Infections
4. Chemical injury
5. Sequestration
42
What is an example of a red cell membrane disorder?
Hereditary spherocytosis
43
What is an example of a red cell enzyme deficiency?
G-6-PD deficiency
44
What is an example of abnormal globin production?
Sickle cell anemia
45
What is an example of deficient globin production?
Thalassemias
46
What is an example of an acquired intrinsic abnormality of RBCs?
Paroxysmal noctural hemolysis
47
What is an example of a mechanical trauma-related extrinsic abnormality?
Microangiopathic hemolytic anemia
48
What are two ways to categorize impaired red cell production anemia?
1. Disturbances of proliferation/differentiation of erythroblasts
2. Disturbances of proliferation/differentiation of stem cels
49
What are three ways to categorize disturbances of proliferation/differentiation of erythroblasts?
1. Deficient heme synthesis
2. Deficient DNA synthesis
3. Multiple mechanisms
50
What is an example of deficient heme synthesis?
Iron deficiency anemia
51
What is an example of deficient DNA synthesis?
Megaloblastic anemia/B12/folate deficiency
52
What is an example of disturbances of proliferation/differentiation of erythroblasts caused by multiple mechanisms?
Anemia of chronic disease
53
What is an example of disturbances of proliferation/maturation of stem cells?
Aplastic anemia
54
What is MCV?
Mean cell volume - volume of the red cell
55
What is MCH?
Mean cell hemoglobin - amount of Hgb/red cell
56
What is MCHC?
Mean cell hemoglobin concentration - amount of Hgb/volume of red cell
57
What is RDW?
RBC distribution width (variation of red cell volume or shape)
58
What is a large variation in red cell volume?
Anisocytosis
59
How are anemias classified by MCV?
1. Microcytic (<80 fL)
2. Macrocytic (>100 fL)
3. Normocytic (80-100 fL)
60
When is sideroblastic anemia seen?
1. Lead poisoning
2. Vitamin B6 deficiency
3. Drugs
4. Chronic alcoholism
5. Myelodysplastic syndrome (malignant)
61
What is the difference between intra/extravascular hemolysis?
Intravascular: RBCs destroyed within vascular compartment
Extravascular: RBCs destroyed by tissue macrophages
62
What is the most common abnormality in hereditary spherocytosis?
Deficiency of spectrin
63
What is the most frequent mutation in the AD form of hereditary spherocytosis?
Mutation in ankyrin gene; leads to reduced synthesis of ankyrin and a secondary reduction in spectrin assembly
64
What is mutated in the AR form of hereditary spherocytosis?
Alpha-spectrin gene
65
What are the clinical features of hereditary spherocytosis?
Anemia
Splenomegaly
Jaundice
66
What is the inheritance pattern of G6PD deficiency?
X-linked
67
What is G6PD used for?
Reforming NADPH, which is used to reduce glutathione to prevent damage from oxidative stress
68
What happens in G6PD deficiency?
H2O2 accumulates and oxidizes sulfhydryl groups of globin chains. Hgb denatures, forming precipitates known as Heinz bodies. These attach to the RBC membrane, causing damage. RBCs with Heinz bodies pass through splenic cords. Macrophages bite out Heinz bodies. Spherocytes form.
69
What is the mutation in sickle cell disease?
Point mutation leading to substitution of Valine for Glutamic Acid at the 6th position of the beta-globin gene - results in HgbS
70
What are a group of genetic disorders characterized by the lack, or decreased synthesis, of either alpha or beta-globin chains of HgbA?
Thalassemias
71
What are the hematologic consequences of thalassemias?
Low intracellular Hgb (hypochromia)
| Relative excess of other chain
72
What codes for alpha-globin chains?
2 alpha-genes on each chromosome 16
73
What are the 4 types of alpha-thalassemias?
1. Silent carrier (1 deletion)
2. Alpha-thalassemia trait (2 deletions)
3. HbH disease (3 deletions)
4. Hydrops fetalis (4 deletions)
74
What codes for beta-globin chains?
1 beta-globin gene on each chromosome 11
75
What is beta degree thalassemia?
Lack of beta-globin expression
76
What is beta + thalassemia?
Decreased beta-globin expression
77
What happens in beta-thalassemia major?
Expanded marrow space, skeletal deformities, hepatosplenomegaly
78
What happens in PNH?
Mutation in PIGA gene leads to deficiency of GPI anchor and lack of GPI-linked protein expression
79
What are 3 important GPI-linked proteins and what are they involved in?
CD55, CD59, C8 binding protein
Inactivating complement
80
What happens to TIBC in iron deficiency anemia?
Increases
81
What are symptoms of iron deficiency anemia?
Spoon-shaped nails, smooth tongue, intestinal malabsorption, esophageal webs (rare)
82
What is nuclear-cytoplasmic asynchrony and where is it seen?
Cellular nuclei are immature and cytoplasm is fully mature
Megaloblastic anemia
83
What are causes of B12 deficient megaloblastic anemia?
1. IF deficiency
2. Pancreatitis
3. Gastrectomy
4. Ileal resection
5. Regional enteritis
6. Parasites (fish tapeworm)
84
___ applies to Vitamin B12 deficiency secondary to atrophic gastritis with failure of IF production.
Pernicious anemia
85
Vitamin B12 is an essential cofactor for 5-methyltetrahydrofolate homocystein methyltransferase, aka ___. Deficiency leads to decreased availability of ___.
Methionine synthase; THF
86
Vitamin B12 is involved in isomerization of ___ to succinyl CoA. Deficiency leads to increased ___.
Methylmalonyl CoA; methylmalonate
87
What are clinical findings of megaloblastic anemia - Vitamin B12 deficiency?
Alimentary tract: atrophic glossitis, chronic gastritis
Blood and bone marrow: megaloblastic anemia, leukopenia with hypersegmented granulocytes, mild to moderate thrombocytopenia
CNS: subacute comined degeneration
88
What clinical finding of Folate deficiency/megaloblastic anemia is unique?
No CNS abnormalities
89
Anemia of chronic disease is caused by high levels of plasma hepcidin - what does this do?
Blocks transfer of iron from macrophages to erythroid precurosrs
90
In ___ anemia, there is failure or suppression of stem cells leading to hypocellular marrow. What are the peripheral blood findings?
Aplastic
Pancytopenia
91
What does the reticulocyte count measure?
Hypo vs. hyperproliferative
92
Where does the name reticulocyte originate from?
From the mesh-like/reticular ribosomal RNA visible under the microscope
93
What does a high reticulocyte count reflect?
Adequate response of the bone marrow
94
What does a low reticulocyte count reflect?
Inadequate response of the bone marrow
95
What is the RI?
Corrected reticulocyte count - % of reticulocytes x (Hct/45)
96
What is a normal RI?
0.5-2.0%
97
What is a normal absolute reticulocyte count?
25,000-75,000 microL
98
What is a virus which replicates in erythroid precursor cells and kills them, leading to aplastic anemia in persons with chronic hemolytic anemias?
Parvovirus B19
99
What are physical exam findings of anemia?
1. Conjunctival pallor
2. Koilonychia
3. Papillary atrophy
4. Angular stomatitis
5. Slapped cheek rash (Parvovirus)
6. Scleral icterus
7. Jaundice
100
MCH = ?
(Hgb x 10)/RBC
101
MCHC = ?
Hgb/Hct
102
What happens to MCH and MCHC in hypochromic anemias?
Both decrease
103
What happens to MCHC in hyperchromic anemias?
Increased
104
Patients with ___ are at risk for infections with encapsulated bacteria.
Sickle cell anemia
105
Patients with malaria may develop symptoms of ___ upon treatment.
G6PD deficiency
106
What represents the amount of iron stored in the body?
Ferritin
107
What is the protein that transports iron through the blood?
Transferrin
108
What measures the body's ability to bind iron to transferrin?
TIBC
High - little iron in the blood, so transferrin is very available
Low - production of transferrin is decreased
109
What indicates how much of the transferrin that is available in the blood is actually boudn to iron?
Serum iron to TIBC ratio
Low - low levels of iron, high levels of transferrin
High - low levels of iron and very low levels of transferrin
110
What are the two most common blood types?
O+, A+
111
What is the difference between the A and B Ags?
A has an extra GALNAC
112
What are RBC isoagglutinins?
Ab against the dominant polysaccharide, naturally occurring
113
RBC isoagglutinins are typically ___ (which Ab). Do they activate complement? What type of hemolysis do they cause?
IgM
Yes
Fast intravascular
114
List the Ab found in plasma and the Ag on the RBC for each blood type.
Group A: anti-B, A Ag
Group B: anti-A, B Ag
Group AB: no Ab, A and B Ag
Group O: anti-A and anti-B, no Ag
115
What is the universal RBC?
Group O
116
What is the universal plasma?
Group AB
117
What are alloantibodies and how do we get them?
Ab against Ag we lack; exposure to Ag on RBCs through pregnancy, transfusion, transplantation
118
Alloantibodies are typically ___ (which Ab). Do they activate complement? What type of hemolysis do they cause?
IgG
Most do not
Slow extravascular
119
Compare and contrast autoantibodies (temperature, Ig type)
Warm: react at 37 C, IgG
Cold: IgM, activate complement
Both have positive DAT/IAT
120
What happens in type and screen?
Determination of ABO and Rh type
121
What happens in forward typing?
Mix patient's RBCs with Antibodies (against A, B, D)
122
What happens in reverse typing?
Mix patient serum with A and B cells
123
What happens in an IAT?
Patient serum + donor blood - look for anti-RBC Ab in serum
124
What happens in a DAT?
Patient RBC + anti-human Ab - look for Ab on RBCs
125
What are possible causes of a positive DAT?
Acute and delayed hemolytic transfusion reactions
Autoimmune hemolytic anemia
Hemolytic diseases of the newborn
126
What are the pre-requisites to develop HDN?
1. Mom lacks Ag and is exposed by pregnancy/transfusion
2. Baby possess Ag
3. Mom produces IgG Ab
127
What are clinical findings of HDN?
1. Hemolysis (anemia, jaundice)
2. Accelerated red cell destruction, followed by compensation (hepatomegaly)
3. Edema (hydrops fetalis)
4. Fetal death
128
When is RhIg administered?
At 28 weeks + within 72 hours postpartum
129
What is autoimmune hemolytic anemia (AIHA)?
AutoAb against RBC Ags
130
What is TRALI?
Transfusion related acute lung injury
Acute onset of respiratory distress during or within 6 hours of transfusion caused by donor HLA Ab against recipient WBCs
131
What is TACO?
Transfusion related circulatory overload
