Editing Maternal and Newborn Nursing (section)

=== Respiratory ===

Progesterone increases tidal volume and minute ventilation, creating a compensated '''respiratory alkalosis''' with a lower normal PaCO2 (roughly 27 to 32 mm Hg). Oxygen consumption rises about 20 percent and functional residual capacity falls, so a pregnant patient desaturates fast during apnea. Dyspnea on exertion and nasal stuffiness are common and benign; dyspnea at rest, orthopnea, or chest pain is not.