Some surgeries take longer than others depending upon the complexity. It really depends upon your overall health to determine if it is safe.
it is certainly acceptable to undergo a facelift, rhinoplasty, and chin surgery at the same setting. These procedures should only take approximally 4 hours under general anesthesia not 8. It's very important to make sure that the surgery is performed in a certified ambulatory surgery center setting, with a board certified physician anesthesiologist in attendance.