The portable closed-wound drainage system draws drainage from a wound site, such as the chest wall postmastectomy (shown at left), by means of a Y tube. To empty the drainage, remove the plug and empty it into a graduated cylinder. To reestablish suction, compress the drainage unit against a firm surface to expel air and, while holding it down, replace the plug with your other hand (as shown in the center). The same principle is used for the Jackson-Pratt bulb drain (shown at right).
