![Shunt vs dead space usmle](https://cdn3.cdnme.se/5447227/9-3/1_64e61dfaddf2b33c615a3cd3.png)
![shunt vs dead space usmle shunt vs dead space usmle](https://rc.rcjournal.com/content/respcare/58/7/1143/F7.large.jpg)
Type 2 – Hypercapnea (Hypoventilation): There are three generalized causes of hypercapneic respiratory failure: Either the CNS is not adequately responding to the increased, the respiratory muscles aren’t adequately responding to the nervous system, or there’s been an increase in dead-space ventilation (so it doesn’t matter if the respiratory muscles adequately contract or not – air still can’t get out). So Type 1 respiratory failure is unique in that this hypoxemia will necessarily be resistant to supplemental oxygen.
![shunt vs dead space usmle shunt vs dead space usmle](https://breathphys.com/wp-content/uploads/2020/04/image-11.jpeg)
![shunt vs dead space usmle shunt vs dead space usmle](https://www.online-sciences.com/wp-content/uploads/2021/07/Regional-difference-in-ventilation-99.jpg)
Note that since it’s the oxygen exchange that’s impaired, it makes sense that just adding more oxygen won’t fix the problem – the oxygen still won’t be able to cross the barrier of the fluid in the alveoli. The shunting is often due to cases of alveolar flooding (pulmonary edema, ARDS, CHF, pneumonia, alveolar hemorrhage). Type 1 – Shunting: You can think of this hypoxemic respiratory failure as failure of oxygen exchange itself.
![shunt vs dead space usmle shunt vs dead space usmle](https://i0.wp.com/airwayjedi.com/wp-content/uploads/2013/01/cover-shadow.jpg)
Using this mnemonic, you can simplify the order of the four types of respiratory failure as Shunting, increased CO2 (hypoventilation), Atelectasis, and Hypoperfusion.
![Shunt vs dead space usmle](https://cdn3.cdnme.se/5447227/9-3/1_64e61dfaddf2b33c615a3cd3.png)