Velocity of ether absorption from visceral pleura; pleura-to-tongue circulation time.

The visceral pleura and its ability to absorb matter either liquid or particulate has been demonstrated.1 These studies dealt with the site and character of absorption, rather than with the readiness with which the injected material is removed.2 In the present communication are certain observations on the velocity with which ether in sterile isotonic solution of sodium chloride placed on the visceral pleura is absorbed and the time required for the same to be tasted. The required time is named the pleura to tongue circulation time, knowing that readily diffusible substances are absorbed directly into the blood vessels.3 Material and Method of Study: Eighteen patients receiving artificial pneumothorax for pulmonary tuberculosis were selected for this study. In all, excepting patients No. 9 and 18, the disease was quiescent. With care for asepsis, 0.3 cc. of ether, and 0.3 cc. of isotonic solution of sodium chloride were drawn into a 2 cc. syringe. After shaking the contents gently five or six times, the solution was dropped directly upon the surface of the visceral pleura through a 20 gauge needle, not taking more than two seconds to do so. The needle for this procedure was inserted in the fourth intercostal space at the midaxillary region. The point of the needle was held at a right angle to the projected spot of the pleural surface to be deluged. Care was taken to prevent the ether from coming in contact with the parietal pleura because when this occurred, the patient felt pain in the thoracic wall. Furthermore, the ether in isotonic solution of sodium chloride was intended to be absorbed by the intrapulmonary vessels and not by the vessels of the thoracic wall. In nine patients, the velocity of absorption of the right lung was studied, and in the rest that of the left lung. The interval between the instillation of the solution and the tasting of ether by the patient is timed and regarded as the velocity of ether absorption or the pleura-to-tongue circulation time.