compliance
In respiratory therapy, the measure of lung and chest wall distensibility, calculated as change in volume per unit change in pressure.
Full Definition
Respiratory compliance describes the ease with which the lungs and chest wall can be inflated, expressed as the change in volume divided by the change in pressure (ΔV/ΔP). Normal static compliance ranges from 50-100 mL/cmH2O. Reduced compliance indicates stiff lungs or chest wall, commonly seen in conditions like ARDS, pulmonary fibrosis, or chest wall abnormalities. Increased compliance occurs in emphysema where lung elasticity is lost. Monitoring compliance helps respiratory therapists assess disease progression, optimize ventilator settings, and evaluate response to treatments. Dynamic compliance includes airway resistance effects, while static compliance reflects true lung and chest wall properties.
Usage
Usage note: Always specify units (mL/cmH2O) and distinguish between static and dynamic compliance.
In Context
- "Static compliance decreased to 25 mL/cmH2O, indicating worsening ARDS." — Ventilator assessment report
- "Improved compliance following bronchodilator therapy suggested reversible airway obstruction." — Respiratory therapy progress note