ED to observation to ED -E/M

[Sabrina.]

Hello all. Pt is in a CAH (which I do not think this would matter). Pt is in ED and admitted to observation. While in observation pt becomes "unstable for the location and is discharged from the nursing unit observation status to the emergency department for further care" and is next transferred to a higher level of care at a different hospital. So a pt needing to be more closely monitored by nursing staff should not reduce the pt admission status, correct? I've never seen a pt admit status reduced back to an ED much less trying to navigate coding the E/M levels for such. Any insight here? Guidelines that are referenceable? Thank you so much