Pulmonary, chest wall, and lung-thorax elastances in acute respiratory failure

Chest. 1981 Sep;80(3):304-11. doi: 10.1378/chest.80.3.304.


The usefulness of lung-thorax compliance (or elastance) as an index of pulmonary compliance (or elastance) was examined in 15 patients being ventilated for acute respiratory failure. Mean lung-thorax elastance (ELT) was 27.9 +/- 2.6 cm H2O/L, and the chest wall accounted for 34 +/- 2 percent of the mean total value. Changes in ELT caused by increments of positive end-expiratory pressure correlated only with changes in pulmonary elastance (r = 0.96; P less than 0.001) and not with chest wall elastance, although individual patients varied as to the contribution of the chest wall component. Lung-thorax elastance increased in direct proportion (1:1) to increases in pulmonary elastance, whereas the changes in lung-thorax compliance were only half those in pulmonary compliance. We conclude that elastance is a more useful clinical index than compliance.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acute Disease
  • Adult
  • Aged
  • Airway Resistance
  • Compliance
  • Female
  • Forced Expiratory Flow Rates
  • Humans
  • Lung / physiopathology*
  • Lung Volume Measurements
  • Male
  • Middle Aged
  • Respiratory Insufficiency / physiopathology*
  • Respiratory Insufficiency / therapy
  • Thorax / physiopathology*
  • Ventilators, Mechanical