Need help with physiology problems

[jcosler2357]

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Thank you for your patience/time to look at this thread.
I know this is not supposed to be the tutoring site, but these three physiology problems are just driving me crazy. Any input is appreciated.
Thank you so much.
PLZ help this poor physiology student.
Question 1) Why would it help an emphysema patient by increasing the ventilation rate and increasing the percent of oxygen in the air that patient is breathing?
Question 2) If the patient is suffering from emphysema that has removed 1/4 of the surface area from 1/2 of their alveoli, why would increasing the contraction of the diaphragm and increasing the percent of oxygen in the air that patient is breathing wouldn't help this patient?
Question 3) If the patient has pulmonary edema that has increased the distance between their alveolar space and capillary blood by 40%, why would increasing the contraction of the diaphragm and increasing the percent of oxygen in the air that patient is breathing wouldn't help this patient?
My thoughts on Q1) As far as I understand it, emphysema patients don't have hard time breathing in. They have hard time breathing out. So, why is it necessary to increase the ventilation rate/percent of oxygen in the air that emphysema patients are breathing if they're breathing in ok and get enough oxygen. Clueless on Q2. Again, clueless on Q3

 

[CJDocS]

Thank you for your patience/time to look at this thread.
I know this is not supposed to be the tutoring site, but these three physiology problems are just driving me crazy. Any input is appreciated.
Thank you so much.
PLZ help this poor physiology student.
Question 1) Why would it help an emphysema patient by increasing the ventilation rate and increasing the percent of oxygen in the air that patient is breathing?
Question 2) If the patient is suffering from emphysema that has removed 1/4 of the surface area from 1/2 of their alveoli, why would increasing the contraction of the diaphragm and increasing the percent of oxygen in the air that patient is breathing wouldn't help this patient?
Question 3) If the patient has pulmonary edema that has increased the distance between their alveolar space and capillary blood by 40%, why would increasing the contraction of the diaphragm and increasing the percent of oxygen in the air that patient is breathing wouldn't help this patient?
My thoughts on Q1) As far as I understand it, emphysema patients don't have hard time breathing in. They have hard time breathing out. So, why is it necessary to increase the ventilation rate/percent of oxygen in the air that emphysema patients are breathing if they're breathing in ok and get enough oxygen. Clueless on Q2. Again, clueless on Q3

Not an expert or anything, but from my understanding, patients who suffer from chronic emphysema have a difficult time during inspiration and expiration. Because of the breakdown of the alveoli in the lungs, there will be a ventilation and perfusion mismatch. Alveoli are replaced by air sacs, increasing the physiologic dead space. So, although the perfusion is ok, the gas exchange is compromised which is why the patient needs an increase in the percentage of O2 in the air they are breathing. Hypoxia is a great concern for patients with emphysema, leading to polycythemia. As far as the ventilation rate is concerned, I'm thinking is has to do with the susceptibility of a patient with emphysema to hypercapnia. I know this probably didn't answer you question exactly, but hope it helped.

 

[Buckeye(OH)]

V=(A/d)*D(P1-P2)

This equation determines rate of gas exchange. The A stands for surface area, and as a result an increase in surface area increases the rate of gas exchange. In emphysema, the surface area is decreased due the alevolar destruction as mentioned above. Increasing the ventilation rate and the %O2 will aid in gas exchange because it will increase the partial pressure gradient between the arterial PO2 and the alveolar or inspired PO2. The pressure gradient is the P1-P2 you see in that equation.

 

[Buckeye(OH)]

Question 3 is very similar to Question 1. Same equation. The little d you see is the distance that the gas must diffuse across. Thus, diffusion rx is inversely proportional to diffusion distance. Edema/fibrosis/pneumonia increase that distance. One way of counteracting that is by increasing the partial pressure of the inspired air. Remember by increasing the percentage of o2 in a gas mixture, you are decreasing the partial pressure and thus the percent composition of other gasses.

 

[Buckeye(OH)]

My guess for the increased diaphragm contraction is the following. There are two types of work, elastic work and resistive work. People that have emphysema want to minimize resistive work or reduce the resistive cost of breathing. To do this they take very long, very deep breaths. That means the try to take large tidal volumes. One way to increase your tidal volume is to increase the volume of the chest cavity, and that can be done by further contracting the diaphragm.

 

[jcosler2357]

Thank you so much 😀 😀