Pulmonary Shunt/Dead-space Ventilation

smf0903 · Jan 25, 2015

Go to YouTube and search for "MedCram V/Q mismatch". There is a video series (5 videos if I recall) that do an superb job of explaining all of this. I also had a hard time wrapping my head around these topics, but the videos did an excellent job of explaining all of these!

Good luck!! :)

Esme12, ASN, BSN, RN · Jan 25, 2015

This may help as well....http://www.ccmtutorials.com/rs/mv/strategy/index.htm

Esme12, ASN, BSN, RN · Jan 25, 2015

Esme12, ASN, BSN, RN · Jan 25, 2015

Dead space is the volume of air which is inhaled but does not take part in gas exchange either because it remains in the conducting airways or in alveoli that are poorly perfused i.e. not all the air in each breath is able to be used for the exchange of oxygen and carbon dioxide.

The total dead space (also known as physiological dead space) is the sum of the anatomical dead space plus the alveolar dead space.

[h=2]Anatomic dead space[/h] Approx one-third tidal volume ~150mL in a healthy adult.

[h=2]Alveolar dead space[/h]

Sum of the volumes of alveoli which have little or no blood flowing through their adjacent pulmonary capillaries i.e., alveoli that are ventilated but not perfused, and where, as a result, no gas exchange can occur.
Alveolar dead space is negligible in healthy individuals, but can increase dramatically in some lung diseases due to ventilation-perfusion mismatch.

https://www.boundless.com/biology/textbooks/boundless-biology-textbook/the-respiratory-system-39/breathing-221/dead-space-v-q-mismatch-840-12085/

nurseprnRN, BSN, RN · Jan 25, 2015

If you think about it, this is why rapid, shallow breathing results in lousy blood gases. The same air is being circulated up and down in the deadspace, but not much fresh is coming in or out, so CO2 rises and O2 falls.

MissChloe · Jan 27, 2015

Thank you! I have passed these answers/resources along to the others in our class and they are very helpful!