I would like some advice towards my mother's next trip.

We just returned from a convention in Las Vegas. While we were there, my mother's ankles got swollen something terrible. The swelling was not so much during flight (except the last leg DFW-YUL and they were swollen before boarding) but in the hotel (Rio Suites). On the last convention day, she spent most of it in her room with her feet up and iced -- the floor ran out of ice and the machine stayed empty for 12+ hours! The very last event, she attended in slippers.

Mom is a senior citizen and the walk between our room and the convention center was 10 minutes for me and 20 minutes for her: indoors, carpeting, no stairs, one not-steep incline.

My ankles held up much better, I can only remember one day of swelling after a lot of racing around. And I was on my feet more than Mom was.

Is there anything that can be done to prevent this happening next year? Does plane altitude play a factor? (we flew AA first class) Any and all replies appreciated.