Modular drainage apparatus having excess negativity control

摘要

A modular drainage apparatus has a plurality of preformed plastic bodies supported by a header. One of the bodies includes a collection chamber connected to the pleural cavity of a patient and connected to a first passage formed in the header. A second body includes a U-shaped liquid seal chamber having one end connected to the first passage and its other end connected to a second passage formed in the header. The second passage is connected to a vacuum pump, which creates a suction within the collection chamber through the liquid seal chamber. A third body includes a U-shaped chamber to regulate the negative pressure produced by the vacuum pump to a desired negative pressure. The second body also includes a second U-shaped chamber having one end connected to the atmosphere and its other end connected to the liquid seal chamber adjacent its connection to the first passage. By filling each leg of the second U-shaped chamber of the second body to a selected level with a liquid, the negative pressure in the collection chamber is maintained at a selected maximum above the pressure maintained in the collection chamber by the vacuum pump and regulated by the U-shaped chamber of the third body.