What could be wrong with my son?

So my son is in da hospital h heas rsv :/ he is in the icu because we hes a sleep his heart ratw and oxygen drops the doctors say evrythings fine dey still trying to figure out why this happens has this happened to anyone? We are in childrens hospital and he has exersizze asthma and hes only ten months old he alSo had twin twin transfusion syndrom so he has been suffering since before he was born idnt know what to do we are always in hospitals :(