the TPN related cholestasis is common in long term TPN, however it ca be delayed if the TPN used carefully,
it is unlikely to see cholestatic jaundice before 4-6weeks of starting TPN.
but if you are careful it can be delayed for 6 and even 12 months after initiating the TPN and this is few tips to decrease the risk like --
1- give cyclic TPN
2- alternative days lipids
3- protein not to exceeds 2.5g/kg/day
4- recurrent sepsis increase the risk of choestasis
4- start the treatment early as mentioned by Stefan Johansson