My interviews are fast approaching and I am starting to freak out a little. I was wondering if you guys could help me with a few concepts.

1.When discussing PEEP, how in depth should I go? I have a basic understanding of what it does (keeps the alveoli open at end expiration and increasing the driving pressure of o2 so you can use a lower Fio2) and why it is used (drive lung water back into vascular space, helps with a shunt) but I am not sure how deep they will want me to answer. Will I need to get into increasing thoracic pressures thus reducing preload resulting in a drop in CO?

2. I cant seem to grasp how a balloon pump reduces preload. My best guess is by dispersing blood to to coronary arteries but I wouldn't think that would be more than a negligible decrease. I understand the afterload reduction.

3. I don't understand Train of 4.

Thanks for the help. This site is incredible.