According to Fick, thickness does matter
Using this gradient, you can distinguish between intrapulmonary and extrapulmonary causes of hypoxia
What is the A-a gradient?
Slide 10; IL 4
Normal: 5-10; increases with age
A FEV1/FVC ratio of less than 0.7 is seen in this class of lung diseases
What are obstructive diseases?
Slide 4
This is the dominant extracellular buffer system in the blood
What is the bicarbonate buffer system?
Slide 8; IL 10
pH = 6.1 + log([HCO₃⁻] / (0.03 × pCO₂))
Fetal hemoglobin has a higher affinity for oxygen than adult due to having a decreased affinity for this molecule
What is 2,3-BPG?
Slide 17
Has gamma chains
This faculty member used to be a historical archeologist
Who is Marcy Jastrab?
Ventilation and perfusion are greatest at this part/zone of the lungs
Bonus: Blood leaving what region/zone of the lungs has the highest PaO2?
What is the base (zone 3)?
Slide 29; IL 4
Bonus: The apex (zone 1)
Note: Although the ventilation and perfusion are the greatest at the base, the V/Q ratio is the lowest
Shunt = wasted perfusion (V/Q = 0)
Dead space = wasted ventilation (V/Q = ∞)
This test accesses how efficiently gasses diffuse from alveoli into the pulmonary capillary blood
What is DLCO?
Slide 10
Remember that DLCO does not distinguish between obstructive and restrictive, but intra- from extrapulmonary problems
This is the respiratory response for metabolic alkalosis
What is hypoventilation?
Slide 22; IL 10
The T form of hemoglobin has this level of affinity for oxygen
What is a low affinity?
Slide 10
This faculty member was both a girl scout and a boy scout
Who is Dr. Martin?
HCO3- leaves and enters RBCs using this ion channel
What is the HCO3-/Cl- exchanger?
Slide 14; IL 5
This type of lung disease would show a shrunken, normal-shaped flow-volume loop
What is a restrictive disease?
Slide 39
These two blood parameters are increased in people who have adapted to a high altitude.
What are EPO and 2,3-BPG?
Slide 13; IL11
Red blood cell size also increases
Carbon monoxide poisoning has this effect on the O2-hemoglobin dissociation curve
What is a left shift?
Slide 31
Remember that CO increases the other sites' affinity for O2
Note: Sickle cell (HbS) shifts the curve to the right
This faculty member played drums for his church
Who is Dr. K?
This effect describes the conformational change of hemoglobin in the lungs, in which the increased O2 promotes unloading of CO2
What is the Haldane effect?
Slide 20; IL 5
The Bohr effect describes the change in peripheral tissues (Increase in H+ and CO2 promote O2 unloading)
The expiratory limb shape in a flow-volume loop would have this appearance in a patient with COPD
What is a "scooped" or concave appearance?
Slide 31
A drug that inhibits this enzyme can be used to prevent acute mountain sickness
What is carbonic anhydrase?
Slide 12; IL11
Reduces bicarbonate reabsorption, speeding up accumulation
These are two treatments for methemoglobinemia
What are methylene blue and vitamin C?
Slide 19
Remember that nitrates/nitrites, sulfa drugs, local anesthetics (e.g. benzocaine), and dapsone can all cause methemoglobinemia
This faculty member played the trombone in the Cleveland Women's orchestra
Who is Dr. Theibert?
A crazy scientist, Dr. Shopley, is trying to turn humans into zombies. He has created gas Z, that has a diffusion coefficient of .7 and a 100mmHG partial pressure gradient across human lungs. Knowing that the thickness of the alveolar membrane is about 0.2 μm and has a surface area of 70 m², what is the rate gas transfer of gas Z?
Diffusion coeffect units: mL*m
mmHg*s
2.45×1010
Slide 18; IL 4
Rate = D*A*ΔP
T
Rate = 0.7 * 70 * 100
2×10−7
0.7 * 49 * 100 = 4900
Rate = 4900
2×10−7
= 2.45 × 1010 mL/s
A tracheal tumor would cause a flow-volume loop to have this shape
What is a box shape (equally plateaued limbs)?
Slide 41
A 26-year-old male is brought to the emergency department by EMS. The patient had recently torn his achilles and was told to take aspirin 2 times day after the surgery. He misheard the physician and took the entire bottle. An arterial blood gas was performed, with the following results:
pH: 7.6
PaCO2: 21 mmHg
[HCO3-]: 12 mEq/L
This is the initial acid-base disorder seen in this patient.
What is respiratory alkalosis?
Slide 12; IL 10, also Truelearn Q5
Acute salicylate poisoning causes hyperventilation; and a high anion gap metabolic acidosis usually follows just after. Continued use will result in respiratory paralysis and thus a respiratory acidosis.
Diagnose type of hypoxia:
PaO2: Normal
Total oxygen content of blood: Normal
Venous PO2: Increased
SpO2: Normal
Remember that hydroxocobalamin and nitrites are used to treat this
This faculty member was a club DJ in college
Who is Dr. Rolfs?