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 AKI, advanced CKD/ESRD, or a dialysis-dependent course carries a reasonable potential for a rapid fluid-electrolyte change; monitoring volume, electrolytes, and the access requires daily nursing judgment.
Covered skilled procedure; management & evaluation
Dialysis-access care and IV medication are covered services under Chapter 8, and managing the renal fluid-electrolyte plan is a skilled service.