Suggest Cure For Congestion In The Esophagus

I am a nurse taking care of a 1 year old boy, (diagnosis is sketchy) possible cross between Rett s syndrome and Angelman s . He has been throwing up for sometime. Only drinks formula for now due to vomiting. He has had lots of congestion in his esophagus on 2 occasions. Both times chest X-rays were clear. He ran a low grade fever and was given an antibiotic. He is also kyphotic and has developmental delays: does not cry , hold head up or sit up yet. His mother tells me his 3 years old sister who died last year had similar symptoms. She said his esophageal sphinter never closed and his kyphosis crushed his lungs. The father seems to be in denial. I love this baby and need help taking care of him successfully, I dont want the family to know that I have consulted anyone. Can your help me with positioning, should he not be lying flat at anytime? I believe this congestion is more from the vomiting and spitting up than a sinus infection.