Oxygen Saturation

nurse assessed the following three fx

-ventilation = determines RR, depth, rhythm, EtCO2

-perfusion and diffusion = determines peripheral O2 sat (SpO2)

capnography

measures partial pressure CO2 (PaCO2) in the blood at the end of exhalation or EtCO2

hypercarbia

increased arterial CO2 → brainstem triggers hyperventilation (out CO2 in O2)

diffusion

movt of CO2 and O2 in alveloi

perfusion

RBS are distributed to and from pulmonary capillaries

arterial O2 saturation

the amount of O2 that pairs with a hemoglobin =SaO2

normal range - 95-100%

venous O2 saturation

O2 saturated in the venous = SvO2

normal range = 70%

peripheral O2 sat (SpO2)

normal range - 95-100%

Spo2 is a reliable estimate of SaO2 as long as the Sao2 is greater than 70%

Sp 02 Less than 90% = clinical emergency