Scared of Hospital

If appropriate, you could look up some details of the ward he will be in.
And/ or the type of procedure he will need.
It would take away some of the unknown element for him.

It's very natural for him to be scared. I would be too. I guess all you can do is try to reassure him, and tell him, quite truthfully, that most hospitals take very good care of older patients, and that you will be with him every step of the way.

I hope he gets a bed very soon so it can be over and done with and he can be home again and much more confortable.

As one who fears the worst before going in hospital, I've always found my fears are unfounded when I'm settled in, but I tell the nurses how I feel because they need to know which patients need that bit more reassurance. They will treat and watch bed sores carefully and make sure your DH moves around so they don't worsen. There are special mattresses to ease pressure on sensitive areas. He'll probably have company on the ward and you should soon find he's feeling a bit more confident. Having you there whenever you can will help, too - if there's anything missing from his care, you're there to speak up for him. Perhaps he'll have some visits from the relatives? I hope it goes well and he's back home quickly.

Your husbands fears are understandable but perhaps you could reassure him that we only hear the horror stories not the thousands upon thousands of patients who are cared for daily with precision and skill. Our doctors and nurses are still among the best in the world. their sole purpose is to make people better- they get no satisfaction from causing you pain and distress. Clearly your husband really needs this admission and he must be feeling very ill so after initial fears which by the way its a good idea to share with the doctors and nurses they will do their very best to allay these perhaps a mild sedative may be prescribed. Hospitals are not the austere places they used to be. Staff are friendly and routines are informal. I'm sure you will be staying with him as much as possible which will comfort him enormously. As to the pressure sores hospital beds are designed to relieve the pressure in a much better way than a domestic bed can and the nusring staff are usually expert in these matters. Many hospitals also have Tissue Viability Nurse who you can ask to see for on-going advice and treatment for the ones he currently has.
I wish you both good care and comfort and that he is home with you again very soon.

If you have time you could perhaps visit the hospital and the ward where he'll be, to see what it's like and meet the staff. If this is allowed.
Also ask about visiting and whether you would be allowed to stay with him.
And find out the procedure for removing fluid and discuss it with him.
Good luck!