PCO2
The PCO2 is the partial pressure of carbon dioxide (CO2) in the blood. Usually the arterial blood is the relevant context; the symbol for PCO2 in arterial blood is PaCO2. Measurement of PaCO2 in the systemic circulation indicates the effectiveness of ventilation at the lungs' alveoli, given the diffusing capacity of the gas. It is a good indicator of respiratory function and the closely related factor of acid–base homeostasis, reflecting the amount of acid in the blood (without lactic acid).
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