Hi welcome to the board A few questions for you
Have you seen a vet in the last year or so i assune you have since he is renal problems
whats the kitty's name BTW?
Screaming at night can be a number of things maybe he wants some company or is gtting anxious cause he cant hear to well .
IF he is coughung more than normal i wouddefinitly say a vet visit is in order
esp with an older cat