Breathing systems

Description

The function of breathing systems is to deliver oxygen and anaesthetic gases to patients and eliminate carbon dioxide. All breathing systems are composed of similar components but are configured differently. The common components include: fresh gas flow, tubing to direct gas flow, an adjustable pressure limiting valve to control pressure within the system & allow scavenging of waste gas and a reservoir bag to store gas and assist with ventilation. Each breathing system receives three sources of gas: fresh gas, exhaled dead space gas and exhaled gas from the alveoli. The proportions of each within the system are most greatly influenced by fresh gas delivery. Gas is delivered to spontaneously breathing patients at sub-atmospheric (negative) pressure during inspiration and atmospheric pressure during exhalation. Conversely, ventilated patients receive gas at positive pressure during inspiration and atmospheric pressure during exhalation. In this presentation, different components and types of breathing systems are discussed.