Hello @abidjan
I am quite new to this group so I do not know any background to your post. I will offer this observation: I imagine that if you are asking this question it is because you have good reason to believe that your brief visit and exit will, indeed, upset him more than it will provide reassurance. If that is the case then, in your shoes, I would follow my informed intuition and not go.

You can put a safety net under that plan by asking the doctors to let you know if their observations of him or their cumulative experience indicates that it is valuable for you to go. In that case, they should give you instructions on what kind of communication would be helpful to his recovery.

It is such a difficult situation. My heart goes out to you. The important thing is that you are ensuring that he gets the medical care that he needs and that which can enable you two to move forward safely You are doing the right things. Bless you.