Darrow-Yannet Diagram

From USMLE Step One Wiki

Tell Volume and Osmolarity Changes of Body Fluids

[1]

Y axis is Solute Concentrations or Osmolarity

X aixs is the volume of ICF and ECF

Abnormalities:

Isosmotic Volume Contraction (Loss of Isotonic Fluid - like Diarrhea, Hemorrhage, Vomiting) - dec ECF Volume only

Isosmotic Volume Expansion (Gain of Isotonic Fluid - Like Isotonic Infusion) - inc ECF Volume only

Hyperosmotic Volume Contraction (Loss of Water - like Dehydration, Diabetes Insipidus) - dec ECF Volume, Inc Body Osmolarity, Dec ICF Volume

Hyperosmotic Volume Expansion (gain of NaCL - Excessive Salt Intake, Hypertonic Mannitol) - Inc ECF Voume, Inc Body Osmolarity, Dec ICF Volume

Hyposmotic Volume Contraction (loss of NaCl - like Adrenal Insufficiency) - Dec ECF Volume, Dec Body Osmolarity, Inc ICF Volume

Hyposmotic Volume Expansion (gain of water - like SIADH, Water Intoxication) - Inc ECF Volume, Dec Body Osmolarity, Inc ICF Volume

See Renal Physiology, Cardiovascular Physiology, Fluid Compartments