Changes in central venous to arterial carbon dioxide gap (PCO2 gap) in response to acute changes in ventilation.

Disturbances around the time of blood sampling can rapidly affect the PCO2, leading to inaccurate calculations of the ∆PCO2, resulting in misinterpretation of patient status. Care should be taken when interpreting blood gases, if there is doubt as to the presence of acute and transient changes in ventilation.