Describe a commonly used pleural drainage system.
Different drainage systems are in use. The most com-monly employed disposable system is a modification of the three-bottle system. It consists of a water seal, a low-negative-pressure water limiter bottle, and a dry trap. The low-negative-pressure water limiter bottle prevents application of excess pressure by allowing entrainment of atmospheric air. Use of only a dry trap bottle (single-bottle system) allows for reversal of air flow into the pleural space and for contamination of the suction source.
Clamping the chest tube is dangerous because it may lead to accumulation of air and fluid in the chest. Elevation of the underwater seal bottle above the patient allows water to flow into the pleural space. Patency of the chest tube is maintained by “milking” and “stripping” (squeezing the tube toward and away from the chest, respectively).