The main cause of such leg swelling in his case is lack of exercise of the calf muscles. So the main solution is also exercise of the calf muscles.
This is what is most important for him to get the swelling down.
Although he has heart failure and you say he is sedentary, I assume that he is not completely bed ridden. Hence you must get him to walk about. Several sessions of a few minutes of walking every day will get the leg swelling down, this is by far the best way to reduce the swelling.
You should of course continue with the TED hose and Lasix, these are also important medications.
Besides the exercise, the other thing that I would recommend is to check for his posture. Often leg swelling gets aggravated due to the choice of recliners. It is most important to avoid recliners and armchairs where there is pressure on the calves. It is always better to lie down flat on the bed with the legs elevated for long periods.
You can look this up here for a personal discussion on this aspect: http://living-with-als.org/Diane/swelling.html
The third thing is a low salt diet. This is also effective in reducing swelling.
Hence, besides the treatment by doctors, these are the three aspects which you should look into which will control the swelling.
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