So I am new to Long term care coding, and having a hard time understanding the sequencing of dx’s. As I know you always code the reason for admit first, but very confused is it the accidental overdose or the acute on chronic respiratory failure

This is one I am working now,

Patient admits to the STCH with acute respiratory failure due to an accidental drug overdose. The patient transfers to the LTCH for continued treatment of acute on chronic respiratory failure.

Thanks for any help given!