The proliferation of HD regimens during the past few decades has generated much confusion and alphabet soup of terms without a firm structure or consistency.  The terminology used in the literature to describe the various HD regimens is confusing, inconsistent and at times simply incorrect (i.e. “daily-nightly HHD”).  In an attempt to improve communication, let us first define a few selected terms frequently used to describe HD regimens:

Quotidian – Daily, recurring every 24 hours, includes nightly.  Generally applied to therapies practiced 5 to 7 days per week.

Hemeral – Refers to therapy provided at home.

Enhanced – As applied to dialytic therapy, the term generally denotes a frequency of every other day or elimination of the two day hiatus without dialysis (3.5 to 4 times per week).  The term “second-daily” is often used in Australia and New Zealand interchangeably with enhanced.  We propose the term HD_3.5 to denote every other day.

Nocturnal – Performed at night.

Nightly – Performed every night or 5 to 7 nights per week.

Daily – Performed every day or 5 to 7 days per week.

Conventional – As applied to hemodialysis, denotes center, hospital or satellite therapy 3 times per week.

We propose the following nomenclature and structure to describe the various regimens and prescriptions of HD, regardless of the location where dialysis is administered (center, home, satellite):

1. Time or duration of dialytic session (qualitative) denoted in lower case
2. Modality (HD, home HD, hemodiafiltration [HDF]) denoted in upper case
3. Frequency of dialysis (sessions per week) denoted numerically in subscript

For example, short daily HD, 5 x/week would be shown as:

Description of typical HD prescriptions