I started my nursing career on a heavy medsurg/stepdown floor in a level 1 trauma center for 3 years and then decided to go to the Perioperative dept. Being in this type of hospital on a medsurg floor you get the heaviest of all medicine pts, the ones that other hospitals cant take care of so believe me you will get plenty of experience workin in a medsurg floor in a level 1 or level2 hospital to prepare you for the OR even though they are completely different. The basics you need to know is good anatomy -number one- then knowing how to accurately assess your patients and know what is going on with them when things go sour. Word of advice, most medsurg floors only require a BLS certification to work, go ahead and get ready to take tha ACLS because that is a requirement in the perioperative dept. I had to have a year of Medsurg before i could even qualify to take the ACLS. Know how to really assess the heart, brain, kidney functions including vascular, gastrointestinal, and neuro. If you really want to go into the OR the BEST place to start is on a surgical floor that specifically gets most if not all of the pts coming out of surgery to be admitted to that unit. Its still considered med/surg you just want to make sure it's a surgical unit, cause some medsurg depts are split up like that, the one i worked on saw mostly your chronic medicine pts, not ones needing surgery. For example, the CHF'ers, ESRD pts, Sickle Cell pts, Alcohol W/D pts, all the nursing home pt's with multiple pressure ulcers.
So my advice is, "yes" a med/surg will prepare you for the OR, but if you really want to get ahead of the game before you go into the OR, work on a "Surgical floor", they are the ones that are recovering these pts from surgery and changing theri dressings and reviewing their discharge instructions with them. Good Luck!