When there is active bleeding associated with prolonged PT,APTT , giving vit k 5mg IV for one dose or repeated dose for 3 days (once/ day for 3 d) ass with plasma

My preference will be to give FFP only after assessing the whole situation (i.e address the etiology). In my unit all the babies get VitK at birth and we rarely repeat it. There is plenty of evidence that initial vit K given IM works as a depot and therefore provides sufficient duration of additional vit K to protect for deficiency.

FFP with single dose 1 mg vit k would suffice

Most of the time this prolonged PT/PTT is due to sepsis induced DIC. I see no harm in repeating a dose in addition to the FFP. But giving it for 3 days is more convention then evidence