Some experimental aspects of the pulmonary mechanics

Abstract

The pleural pressures can be qualitatively and quantitatively substituted by the esophagic pressures when the balloon catheter is introduced un-inflated.

Hysteresis phenomena, subsequent elasticity and relaxation in the «in situ» and isolated lungs are described.

The elasticity curve has an elongated S form with a compliance of 0.028 liters per cm. of H2O, on its central zone which is straight, which gives an elasticity module similar to man’s.

The compliance of the isolated lung is lower to that of the «in situ» lung, and that of this last one is lower than the dinamic compliance of the living dog. With the injection of histamine (or acetylcholinc) we observed, after an apnea phase, a great increase in the pulmonary work and on its elastance which is related to a pulmonary vascular ingurgitation, being the bronchospasm light at first and inexistent at the end.

Prostigmin causes an increase in the pulmonary work which we relate to the bronchospasm which is very marked with this agent.