Final answer:
Decreased PECO2 or PetCO2% with normal ventilation can be an indicator of respiratory alkalosis.
Step-by-step explanation:
Decreased PECO2 or PetCO2% with normal ventilation can be an indicator of respiratory alkalosis. Respiratory alkalosis occurs when there is excess CO2 elimination, leading to a decrease in the concentration of CO2 in the blood. This can be caused by hyperventilation, anxiety, or certain medical conditions.