Neonatal Nurse Practitioner Practice Exam

What physiological changes are associated with right shift in the oxygen-hemoglobin dissociation curve?

1. Decrease in CO2 and temperature

2. Increase in 2-3DPG and acidosis

3. Increase in pH and HCO3

4. Decrease in pH and increase in HCO3

The correct answer is: Increase in 2-3DPG and acidosis

A right shift in the oxygen-hemoglobin dissociation curve indicates a decreased affinity of hemoglobin for oxygen, which facilitates oxygen release to the tissues. This shift is influenced by several physiological changes in the body. The correct answer emphasizes an increase in 2,3-Diphosphoglycerate (2,3 DPG) levels and acidosis. An increase in 2,3 DPG occurs in response to conditions such as chronic hypoxia, anemia, or high altitudes, where the body needs to release more oxygen to the tissues. In addition, acidosis, which is characterized by a decrease in pH (higher hydrogen ion concentration), also induces a rightward shift. This condition often arises from metabolic or respiratory processes that increase carbon dioxide levels, leading to more hydrogen ions in the blood, further promoting the release of oxygen. The other options do not align with the physiological mechanisms involved in a right shift. A decrease in CO2 and temperature would actually lead to a left shift, where hemoglobin holds onto oxygen more tightly. An increase in pH and bicarbonate (HCO3) reflects a more alkaline environment, which again typically results in a leftward shift. Finally, a decrease in pH alongside an increase in