Map which Chapter 8 bases apply, then show the need is daily and can be met only in a SNF (the practical-matter test). This is what a coverage reviewer looks for on a Part A day.
Observation & assessment of an unstable condition
A recovering COPD exacerbation carries a reasonable potential for a recurring exacerbation or respiratory failure; the oxygen-target assessment and exacerbation surveillance require nursing judgment daily.
Covered skilled procedure; teaching
Oxygen management and nebulized treatments are covered services under Chapter 8, and inhaler/action-plan teaching to competence is a covered skilled service that reduces readmission.