IVC Collapsibility / Distensibility Index
IVC respiratory variation: distensibility (mechanical ventilation) or collapsibility (spontaneous breathing) from maximum and minimum IVC diameter; ~18% (mechanical) / ~42% (spontaneous) predicts a fluid response.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Ventilation mode
- Mechanical ventilation (distensibility index)
- Maximum IVC diameter
- 2.0 cm
- Minimum IVC diameter
- 1.6 cm
Result: IVC distensibility 25% (Dmax 2 / Dmin 1.6 cm): >= ~18% -- predicts a fluid response (mechanically ventilated).
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Mechanical
- distensibility dIVC = (Dmax - Dmin) / Dmin x 100; about 18% predicts a fluid response in the ventilated patient.
- Spontaneous
- collapsibility (caval) index = (Dmax - Dmin) / Dmax x 100; a high value (about 40-50%) suggests responsiveness. Match the index to the breathing mode.
What you enter
- Ventilation mode
- Maximum IVC diameter
- Minimum IVC diameter
How this is calculated
Barbier C, Loubieres Y, Schmit C, Hayon J, Ricome JL, Jardin F, Vieillard-Baron A. Respiratory changes in inferior vena cava diameter are helpful in predicting fluid responsiveness in ventilated septic patients. Intensive Care Med. 2004;30(9):1740-1746. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.