I think that with an ageing ex pat community, many of whome maybe dont speak spanish and dont have family here there is a room for such work. Im not sure how one would go about setting up, but I think if it was done properly it could be a good business / service to offer.
People here look after their own, so fo those who dont have a lot of family to hand it can be a lnely and worrying experience to grow old here. There simply isnt provision made.
For me just wonderful that people do take care of their ageing relatives but for those who dont have that luxury of family,not so wonderful.
There are a few people doing it already helping hands, starlight and a german company too, maybe start by asking them?