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PHARMACOKINECTICS:

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-factors affecting inspiratory concentrations (FI)
-factors affecting alveolar concentrations (FA)
-factors affecting arterial concentrations (Fa)
-factors affecting elimination

FACTORS AFFECTING INSPIRED CONCENTRATIONS: (FI)

Inspired gas mixture generally depends on:
-fresh gas flow rate (FGF)
-volume of breathing circuit
-machine or breathing circuit absorption

ex. high FGF lead to a smaller breathing system volume and lower absortion by the circuit
therefore the inspired gas concentration will be closer to the fresh gas concentration

FACTORS AFFECTING ALVEOLAR CONCENTRATIONS (FA)
-uptake of anesthetics
-ventilation
-concentration effect
-second gas effect (concentrating effect, and augmented inflow effect)

FACTORS AFFECTING ARTERIAL CONCENTRATIONS (Fa)
-ventilation/perfusion mismatching