Suction devices

Suction devices have widespread uses in the clinical environment. The process of suction is the removal of fluid or other debris using a vacuum, and the properties of suction devices are governed by the physics of the flow of fluid through a tube. The rate of flow is dependent on the radius, length and pressure difference across the ends of the tube. A pump is used to create the vacuum, the efficiency of which depends on the maximum displacement and degree of sub-atmospheric pressure that is generated. A high-efficiency, high-pressure system is used for the removal of vomit and secretions from the airway; a low-pressure system is used for intercostal drains. A central electrically driven pump is utilized in most clinical areas, but portable systems are available. The main components of a suction device are the pump, control box, reservoir, transfer tubing and suction catheter. Safety features prevent contamination of the pump and atmosphere by waste particles. Adverse effects of airway suction by rigid or flexible catheters include soft tissue trauma and airway obstruction as well as hypoxaemia, atelectasis and cardiovascular instability.