repeated hospital admissions for young child, what next?

My 17 month old grandson was diagnosed after being in PICU for several days on a ventilator in early March. Prior to this he'd been in and out of hospital and prescribed salbutamol - they said his breathing difficulties were a result of contracting bronchiolitis in Sept 2010. He is now on Salbutamol, Beclomethosone(Brown inhaler) and Montelukast ( for the last 3 weeks) Since coming out of intensive care he has been admitted a three more times and given oral steroids, nebulised salbutamol and oxygen each time until his SATS return to normal. It seems that following discharge he's OK for about 3 weeks then gets a runny nose fore a couple of days, followed by a cough, refuses to eat, vomits and then gets the intercostal reactions and flaring nostrils - this happens within a few hours of the onset of cough. He also sweats a lot on his head and has quite a protruding chest. It seems that they tweak his meds but the end result is the same A&E and a very poorly little boy and no offer of any further tests. They just patch him up and send him home.

I wonder if anyone can recommend any tests? or has any similar experience? We just don't feel that the problem is being addressed - this must be a pretty severe case if he's been admitted to hospital so many times and he's in again tonight.