Background and Significance/Preliminary Studies Carbon dioxide (CO2) measurement is part of the fundamental respiratory evaluation in an ICU, as both high and low values of CO2 can have detrimental effects on neonatal health. The partial pressure of CO2 reflects ventilation, which is the elimination of carbon dioxide. The ABG sample is the clinical tool most commonly used to evaluate acid-base physiology at the bedside. It directly measures the pH, arterial partial pressure of oxygen, and arterial partial pressure of CO2. Though direct measurement of CO2 in the arterial blood is the most accurate way to assess the amount of CO2, it requires blood sampling from the arteries and does not provide continuous monitoring of CO2.