Effect of volume history on measurements of respiratory mechanics using the interrupter technique

The importance of the viscoelastic properties of the tissues of the respiratory system has recently been recognized, and lung models have been produced to describe the resistive and viscoelastic properties of the lung. The pulmonary mechanics of 10 rabbits were studied using the interrupter technique to assess the effect of volume history on the resistive and viscoelastic elements of the respiratory system. The influence of the tone of the muscles of respiration was also studied. In healthy lungs, the resistive and viscoelastic elements of the lung are dependent on the volume history of the respiratory system and are significantly lower if these elements do not reach a resting position before expiration. The chest wall made a significant contribution to the resistive and viscoelastic elements of the respiratory system, which was also dependent on the lung volume history. The tone of the muscles of respiration had no effect on the resistive or viscoelastic elements of the respiratory system.