Anesthetic Equipment & Monitors : Breathing Systems

Breathing Systems

Breathing systems provide the final conduit for the delivery of anesthetic gases to the patient. Breathing circuits link a patient to an anesthe-sia machine (Figure 3–1). Many different circuit designs have been developed, each with varying degrees of efficiency, convenience, and complexity.

Most classifi cations of breathing systems artifi-cially consolidate functional characteristics (eg, the extent of rebreathing) with physical characteristics (eg, the presence of unidirectional valves). Because these seemingly contradictory classifications (eg, open, closed, semiopen, semiclosed) often tend to confuse rather than aid understanding, they are avoided in this discussion.