L68-72 Flashcards
Compliance = ?
Change in V/Change in P
When is compliance increased?
Loss of elastic recoil (emphysema)
When is compliance decreased?
Increased elastic recoil (pulmonary fibrosis)
Why is there no blood flow through zone 1 of the lungs normally?
Alveolar pressure»_space; arteriole and venous pressures
What happens to minute ventilation and PaCO2 during exercise?
Minute ventilation increases
PaCO2 is normal
What happens to minute ventilation and PaCO2 during a panic attack?
Minute ventilation increases
PaCO2 decreases
What happens to minute ventilation and PaCO2 with increased dead space and intact CNS?
Minute ventilation increases
PaCO2 is normal
What happens to minute ventilation and PaCO2 with increased dead space but without an intact CNS?
Minute ventilation is normal
PaCO2 is increased
What happens to minute ventilation and PaCO2 with PE?
Minute ventilation is increased
PaCO2 is decreased
What is PaO2?
Partial pressure of oxygen in the veins
What is SaO2?
Saturation of Hgb - how much of your available Hb sites around bound to oxygen?
What is CaO2?
Content of O2 in the blood - how much oxygen is contained per dL of blood?
What is DaO2?
Delivery of O2 - how much O2 is delivered to the periphery?
What is saturation at PO2 of 40? 60?
75%
90%
What happens to PaO2, SpO2, CaO2, and DaO2 in lung disease?
All are low
What happens to PaO2, SpO2, CaO2, and DaO2 at altitude?
All are low
What happens to PaO2, SpO2, CaO2, and DaO2 in CO poisoning?
All BUT PaO2 are low
SpO2 is normal by pulse ox
What happens to PaO2, SpO2, CaO2, and DaO2 in anemia?
PaO2 and SpO2 are normal; CaO2 and DaO2 are low
What happens to PaO2, SpO2, CaO2, and DaO2 in cardiomyopathy?
All but DaO2 (low) are normal
A-a gradient = ?
P(alv)O2 - PaO2
P(alv)O2 = ?
[(P(B) - P(H2O)) x FiO2] - (PaCO2/RQ)
What is a normal PmvCO2 and PmvO2?
PmvCO2: 45 mmHg
PmvO2: 40 mmHg
What is a normal PaCO2 and PaO2?
PaCO2: 40 mmHg
PaO2: 95 mmHg
What is a normal A-a gradient?
(Age/4) + 4
What happens to A-a gradient in most diseases?
Increases (but not with altitude, decreased FiO2, or hypercapnea)
What is the barometric pressure at 15,000 feet?
450 mmHg
What causes the Oxy-Hgb dissociation curve to shift right?
Increased temperature
Increased 2-3 DPG
Decreased pH
(Decreases affinity)
What is VQ mismatch?
Decreased V relative to Q
What is Shunt?
No O2 reaches capillaries
Diffusion-perfusion impairment is occasionally seen in ___.
Cirrhosis
What is the first stage of RBC released from the marrow into peripheral blood?
Reticulocyte
What is the normal life-span of RBCs?
120 days
What is the unique structure of the RBC membrane and what are its components?
Membrane skeleton; spectrin fibers + ankyrin
Heme consists of four ___ groups joined into a large ring with a ___ ion incorporated into the center.
Pyrrole; ferrous
Two ___ dimers form hemoglobin.
Globin
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
What are 3 ways to categorize anemia (according to lecture)?
- Blood loss (acute vs. chronic)
- Increased rate of destruction (hemolytic anemias)
- Impaired red cell production (diminished erythropoiesis)
How are hemolytic anemias further categorized?
Intrinsic vs. extrinsic abnormalities of RBCs
How can intrinsic abnormalities of RBCs be further categorized?
Hereditary vs. acquired
How can hereditary intrinsic abnormalities of RBCs in hemolytic anemia be further categorized?
- Red cell membrane disorders
- Red cell enzyme deficiencies
- Disorders of hemoglobin synthesis (structural abnormality vs. deficient globin synthesis)
What are the extrinsic abnormalities of RBCs in hemolytic anemia?
- Ab mediated
- Mechanical trauma
- Infections
- Chemical injury
- Sequestration
What is an example of a red cell membrane disorder?
Hereditary spherocytosis
What is an example of a red cell enzyme deficiency?
G-6-PD deficiency
What is an example of abnormal globin production?
Sickle cell anemia
What is an example of deficient globin production?
Thalassemias
What is an example of an acquired intrinsic abnormality of RBCs?
Paroxysmal noctural hemolysis
What is an example of a mechanical trauma-related extrinsic abnormality?
Microangiopathic hemolytic anemia
What are two ways to categorize impaired red cell production anemia?
- Disturbances of proliferation/differentiation of erythroblasts
- Disturbances of proliferation/differentiation of stem cels
What are three ways to categorize disturbances of proliferation/differentiation of erythroblasts?
- Deficient heme synthesis
- Deficient DNA synthesis
- Multiple mechanisms
What is an example of deficient heme synthesis?
Iron deficiency anemia
What is an example of deficient DNA synthesis?
Megaloblastic anemia/B12/folate deficiency
What is an example of disturbances of proliferation/differentiation of erythroblasts caused by multiple mechanisms?
Anemia of chronic disease