If the infant is experiencing a non-organic failure to thrive, the nurses should maintain a consistent, structured environment. This will help the infant learn how to thrive in his new living situation. The infant should also have as few caretakers as possible. This will keep the infant familiar with the caretaker.
There are many reasons this is why this is the case. The main reason, as the previous answer has stated, is that a structured environment will promote growth in the infant.
However, I am not a nurse. Nothing I have put into this answer should be considered sound medical advice, since it was hobbled together from what I found on the internet. However, it’s a good idea of what needs to be done.