During the first 72 hours in the life of a healthy newborn,what changes would be expected in arterial blood gases?
I.pH would increase
II.PaCO₂ would decrease
III.HCO₃- would increase
IV.PaO₂ would increase

Question

Quizplus · Accepted Answer

During the first 72 hours of life, a healthy newborn's arterial blood gases undergo several changes as the baby adapts from a fetal to a neonatal circulation. The pH increases as the initial mild acidosis from birth is corrected. PaCO₂ decreases as the newborn begins to breathe air, eliminating carbon dioxide more effectively. PaO₂ increases as the lungs expand and the baby starts breathing oxygen from the air, improving oxygenation. HCO₃- (bicarbonate) levels may initially decrease as part of the compensation for the respiratory changes and the correction of acidosis, not increase, which is why option III is not expected.

During the First 72 Hours in the Life of a Healthy