Neonatal Nurse Practitioner Practice Exam

What indicates uncompensated metabolic acidosis regarding CO2 levels?

1. Normal CO2

2. Increased CO2

3. Decreased CO2

4. Fluctuating CO2

The correct answer is: Normal CO2

In uncompensated metabolic acidosis, the key factor to consider is the body's response to acid-base imbalances. In this condition, the primary disturbance is a decrease in bicarbonate levels (HCO3-), leading to a decrease in blood pH. To assess the respiratory response, it is important to look at carbon dioxide (CO2) levels. Normally, in response to metabolic acidosis, the respiratory system attempts to compensate by increasing ventilation, which helps to blow off CO2 and raise the pH back to normal levels. However, in uncompensated metabolic acidosis, this compensatory mechanism has not yet kicked in effectively, resulting in CO2 levels remaining within the normal range. The body's inability to adequately reduce CO2 in response to the acidotic state indicates a lack of compensation. This understanding of the relationship between bicarbonate levels and CO2 is crucial in determining whether the metabolic disturbance has been compensated adequately or remains uncompensated. Therefore, normal CO2 levels strongly suggest that the body has not yet started its compensatory mechanisms to address the acidosis, marking the state as uncompensated.