#1. I suggest you look up the causes of low potassium; I think you'll find your answer there. Potassium in IV fluids is standard with one of the issues your patient has.
#8. You've got repositioning, check vitals, notify MD, start O2 if indicated. Rachael mentioned a complete, thorough respiratory assessment. How does she look? Is she short of breath? Does she have a cough, and if so, is it productive? What are her respirs like--shallow, fast, slow (could she be over sedated, or could she not be breathing deeply because of the pain? Has she been sleeping hard?) How does she appear after repositioning--did her sats/respirs improve? How does she feel--does she feel short of breath, ill, fatigued; or is she feeling pretty good? What do her tests say? Didn't she have a CXR this morning? What about labs, did they do a CBC?
#9 Absolutely you are going to premedicate if necessary. What else can you do to relieve her pain--how about a splint pillow for when she coughs or repositions? You should also educate her and her family on the potential for post-surgery lung complications, and you are going to educate her on the use that ISP and encourage her to do it at least every two hours while she's awake. ISP is VERY important. Maybe you could get her up to a chair for meals TID after she has successfully dangled, in addition to making sure she ambulates. Educate, educate, educate, reinforce education, provide written info if possible, support, and educate!!!
#12. The only thing I would add is that with pneumonia, they often order RT tx. With atelectasis, unless the pt is having a hard time, we typically do more ISP, TDB&C, and increased activity.
You're doing well!