elastance
Pronunciation: ee-LAS-tance
Measure of lung stiffness calculated as driving pressure divided by tidal volume, used to guide ventilator management in ARDS.
Full Definition
Elastance is a measure of the elastic properties of the respiratory system, representing the pressure required to achieve a given change in lung volume. In mechanical ventilation, it is calculated as driving pressure (plateau pressure minus PEEP) divided by tidal volume, expressed in cmH2O/mL. Elastance reflects lung stiffness and compliance, with higher values indicating stiffer lungs. It has gained importance as a bedside parameter for personalizing PEEP settings and tidal volumes in patients with ARDS, as it may better predict ventilator-induced lung injury risk than traditional parameters like plateau pressure alone.
Usage
Usage note: Include units (cmH2O/mL) and distinguish from compliance (reciprocal relationship).
In Context
- "The patient's elastance increased from 15 to 25 cmH2O/mL, suggesting worsening ARDS." — Respiratory therapy assessment
- "PEEP was titrated to minimize elastance while maintaining adequate oxygenation." — Mechanical ventilation protocol