View Full Version : Another V/Q question

04-02-2006, 11:11 PM
Now you have a patient with an embolism occluding his pulmonary artery, so tell me

what is going to be his V/Q ratio?

In a blood flow obstruction the V/Q will be infinite, NO gas exchange in a lung that is ventilated but not perfused

04-04-2006, 11:14 AM
Yes you are right!!!

In an embolism of the pulmonary artery there is a decrease of perfusion wich is the denominator of the formula V/Q so the ratio will iincrease
mmm....and Let me see,
Ventilation with no blood flow, looks like a dead space to me!! what do U think?

Yes it acts like a dead space because there is enough air but no blood flow exctaly the same that happend at alveolar dead space

04-04-2006, 12:14 PM
What happens if it's an airway obstruction?

V/Q would be close to or approaching zero; and it is most likely due to a shunt.

08-30-2006, 09:30 PM
also, during increasing V/Q ratio think about it that ur at apex of lung(high ratio= high lung ie Apex, low ratio= low lung i.e. Base).

@ Apex w/ high V/Q ratio(overventilated), high Po2, high pH(this means low PC02)
@ Base lung low V/Q(underventilated), low po2, low pH(high Pco2)

just easier to remember....

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