What anesthetic do you think should be used for diana's surgery? explain your reasoning?

The anesthetic that should be used is Propofol.  Propofol would be the ideal choice for this long operation, the patient would be put to sleep and feel no pain so the surgeon can proceed with the operation and Propofol is used to help you relax before and during general anesthesia for surgery or other medical procedure and critically ill patients who require a breathing tube connected to a ventilator. 

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.