Darrow Yannet diagram

Introduction:

• A Darrow Yannet diagram (D-Y diagram) is a schematic used in physiology to identify how the volumes of extracellular fluid and intracellular fluid alter in response to clinical conditions
• X axis represents volume
• Y axis represents solute osmolarity.

Principles:

1. Addition or loss of fluid occurs from the ECF only
2. ECF osmolality determines the shift of fluid
3. Shift of fluid occurs till osmolality of ECF & ICF are same.

6 types of diagrams:

Addition of isotonic fluid

Addition of hypotonic fluid

Ex: SIADH

Addition of hypertonic fluid

Loss of isotonic fluid

Ex: Hemorrhage/ Burns

Loss of hypotonic fluid

Ex: Diabetes insipidus (ADH deficiency)

Loss of hypertonic fluid

Ex: Addison’s disease (mineralocorticoid deficiency)