drainage /drā″nij/ [AS, drachen, teardrop] , the removal of fluids from a body cavity, wound, or other source of discharge by one or more methods. Closed drainage is a system of tubing and other apparatus attached to the body to remove fluid in an airtight circuit that prevents environmental contaminants from entering the wound or cavity. Continuous bladder irrigation is drainage in which a body area is washed out by alternately flooding and then emptying it with the aid of gravity, a technique that may be used in treating a urinary bladder disorder. Open drainage is drainage in which discharge passes through an open-ended tube into a receptacle. Suction drainage uses a pump or other mechanical device to assist in extracting a fluid. See also postural drainage, tidal drainage.
