Hi Mohammed,

You don't mention the country or type of programme context. As a first step I would recommend consulting the national treatment guidelines since protocols may vary country to country and depend on the type of programme environment. 

Firstly, any child aged less than 6 months at presentation should be treated according to the protocols for a child aged less than 6 months irrespective of the weight. The type of milk given in the first stage will depend on their condition and on national guidance. If the infant has oedema they should be started on F75 using the protocol for an oedematous child. If there is no oedema then the child may be started on F75 or Diluted F100 depending on national guidance. 

If the child is aged more than 6 months and weighs less than 4kg the type of treatment also depends on the national guidance. In some guidelines this child would be treated in inpatient care. In other guidelines the weight cut off for inpatient care may be 3.5kg or 3kg, whilst in others there is no wieght cut off. In context where infants have access to skilled counselling in the outpatient setting, they may remain an outpatient unless there are complications requiring transfer to inpatient care (e.g. see WHO guideline updates from 2013).

The criteria for exiting the transition phase (to phase 2 or outpaitent care) depends on the programme context and how the transition phase care is delivered (e.g. using F75,  or F100 and RUTF or F100 alone). Regarding discharge, the 15% weight gain criterion has largely been abandoned but is still present in some guidelines. Discharge from treatment in an inpatient setting for children aged more than 6 months where there is no CMAM programme is more frequently based on absolute values of MUAC orweight for height, absence of oedema and clinical status.

For guidance on protocols for infants and children please see the WHO updates of 2013 https://www.who.int/publications/i/item/9789241506328 

National guidelines should take precendence. For an example of protocols for transition and discharge please see these generic guidelines for West Africa: https://tinyurl.com/mryrvn86 

WHO guidelines on the management of wasting and nutritional oedema are currently under review and should become available later this year or early next year. 

I hope this helps,