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paba
Forum Senior

Topics: 15
Posts: 57

04/21/06 - 06:35 AM

A 40 yr old man is admitted to hospital because of chronic cough and dyspnea.Pulmonary function tests and an arterial blood sample reveals following:

End tidal air PO2 =95mmHg
Vital capacity =1.5L below normal
FRC =0.8L above normal
RV =0.4L above normal
PaO2 =72mmHg
PaO2(breathing enriched O2) =95mmHg

Which is the most likely cause of hypoxemia?

A.Decreased pulmonary diffusion capacity
B.Generalised hypoventilation
C.Lt. to Rt.shunt
D.Rt.to Lt.shunt
E.very low V/Q ratio

robin082006
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Topics: 471
Posts: 5,125

04/21/06 - 09:23 AM

B, this patient has COPD

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paba
Forum Senior

Topics: 15
Posts: 57

04/23/06 - 06:48 AM

Given Answer is A.

Geroo
Forum Guru

Topics: 114
Posts: 799

04/23/06 - 08:54 AM

the A-a gradient is large so it can't be hypoventilation,A is the right answer.

robin082006
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Topics: 471
Posts: 5,125

04/23/06 - 09:43 AM

What is the minimum of A-a gradient that can be considered abnormal?

Edited by robin082006 on 04/23/06 - 10:14 AM

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ramo7
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Topics: 15
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04/23/06 - 03:47 PM

answer is A

cool_guyp4u
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Topics: 12
Posts: 124

04/24/06 - 09:08 AM

A and it is tough to make a definitive/ differential diagnosis with the info given.

paba wrote:
A 40 yr old man is admitted to hospital because of chronic cough and dyspnea.Pulmonary function tests and an arterial blood sample reveals following:

End tidal air PO2 =95mmHg
Vital capacity =1.5L below normal
FRC =0.8L above normal
RV =0.4L above normal
PaO2 =72mmHg
PaO2(breathing enriched O2) =95mmHg

Which is the most likely cause of hypoxemia?

A.Decreased pulmonary diffusion capacity
B.Generalised hypoventilation
C.Lt. to Rt.shunt
D.Rt.to Lt.shunt
E.very low V/Q ratio

doc179
Forum Guru

Topics: 67
Posts: 1,217

04/24/06 - 09:32 AM

in physio the normal A-a gradient ranges from 5 - 10. But I think Goljan said in his audio that if the gradient is more than 30 it is considered abnormal. need to look it up somewhere else

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