Just in case others have the same question or concern, here is what happened in my case.
I was admitted the day before surgery and Hephrin drip started. This IV was used throughout my stay at the hospital (5 days) until my Coumadin/Warfarin #'s were regulated. I could have went home on day four but was kept as a precaution. From what I understand, the Hephrin can be turned off 30 minutes before surgery and started afterward where the Coumadin had to be stopped four days prior to surgery and weaned back in.
Hephrin (fast acting) and Coumadin (long acting, stays in system).
Surgery went well for my Lap Band. I experienced a lot of shoulder pain from the gas and the first week was a lot harder than I expected but I am older (51). I was glad that I was in the hospital for that week due to the pain involved while I adjusted to the new me. I was back to work the following week although I did not stay a full day for a few days but day by day, I did better, felt better, etc. I am loving the results and would definitely do this again.
Hope this helps to all others on Coumadin.