nbme 6 how does CPAP help in OSA??

[sadaca]

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could someone plz explain how CPAP helps exactly and how to choose between choices D E and A

god bless thank you
A 48-year-old man comes to the physician with his wife because of a 1 0-month history of headache and daytime sleepiness. His wife says that he snores at night and often stops breathing while sleeping He has no history of any major medical illness and takes no medications He is 173 cm (5 ft 8 in) tall and weighs 115 kg (253 lb) BMI is 39 kg/rn2. His blood pressure is 150/110 mm Hg Physical examination shows no other abnormalhes. Overnight polysomnography confirms the diagnosis Noctumnal treatment with nasal bi-level positive airway pressure is most approprate for this patient to accomplish which of the following?
A) Allowing the airway to remain patent for appropriate ventilation
B) Decreasing the work of breathing during the respiratory cycle
C) Reducing airway secretions during the ventilatory cycle
D) Stimulating increased lung compliance on inspiration and decreased lung compliance on expiration
E) Stimulating increased respirations by splinting the mouth and nose

 

[notbobtrustme]

It's positive pressure back into the airways, so it'll keep them open instead of allowing them to shut close without the pressure. Remember, OSA is basically a piece of garbage collapsing on the airway. If you apply a bit of air pressure back into the airway during expiration, you can keep that piece of garbage away from the airway and let the guy breathe normally.

It's the same principle behind why COPD patients breathe at a high volume with a prolonged FEV1. By applying back pressure, they can keep their airways open and keep breathing.

 

[sadaca]

okay I see, so you're saying A? b/c I was looking up CPAP online and it says it actually causes a "splint" .. And for COPD they have problem expiration so you do PEEP right to create a positive pressure to expire air out easier..and FEV1 is much lower..agree?

thanks!

 

[notbobtrustme]

okay I see, so you're saying A? b/c I was looking up CPAP online and it says it actually causes a "splint" .. And for COPD they have problem expiration so you do PEEP right to create a positive pressure to expire air out easier..and FEV1 is much lower..agree?

thanks!

yep, that's all right. Not sure where you got your information about a splint, but the wikipedia page on CPAP says what I was saying http://en.wikipedia.org/wiki/Continuous_positive_airway_pressure

COPD do PEEP by themselves, otherwise they collapse their airway and can't breathe. PEEP is more for hospitalized patients, IIRC, and helps get people off ventilators faster, but the principle is similar.

 

[sadaca]

Ok I see , thanks alot!
I have 2 behv qs could u see if you know these?

49 yo woman hasn't slept 2 wks, denies previous history of sleep difficulty, drunk 1 bottle of wine for the past week, but hasn't drunk in the past. Demands to be seen by the head of the department. Speech is rapid, pressured, she is irritable. She got major depressive disorder 6 years ago. What's her Dx now?
-alcohol withdrawal
-alcohol halucinosis
-alcoholism
-bipolar disorder
-cyclothymic disorder W( why not this? )

5-A study is done to determine the efficacy of fish oil in preventing progression of renal disease in patients with lgA nephropathy. 100 consecutive patients with newly diagnosed lgA nephropathy are entered into the study. The odd numbered patients are treated with fish oil and the even numbered patients are treated with olive oil, an inactive fatty acid. Over the next 5 years, all patients are followed for the development of end-stage renal disease. Results are shown:
. #reaching end Stage Renal Disease
Fish oil Group (n=50) 3
Olive oil Group (n=50) 17

The incidence of end stage renal disease in the fish oil group was significantly lower than in the Olive oil group (p<0.01). which of the following best describes the Study?
A. Case- Control
B. Case Series
C. Cohort ( why is this wrong, its being FOLLOWED over time)??
D. Controlled Trial
E. Crossover
F. Cross-Section