Swan-Ganz, also known as a PA catheter, is an invasive monitoring device used to take all kinds of different measurements of cardiac function (giving some indications as to what might be going on with many body systems).
The open and closed drain would be from a ventriculostomy drain, for CSF drainage. If someone has an elevated ICP and the drain is clamped (or closed), one of the first things to do is open the drain to hopefully get rid of some excess fluid (causing increased pressure).
Interesting flow chart. I have never seen a Swan put in for a neuro patient in the early stages of TBI or other neuro insult. Is that routine somewhere??