How is ARDS defined and managed in obstetrics?

How is ARDS defined and managed in obstetrics?

• A. PaO2/FiO2 < 200 with unilateral infiltrates; conservative ventilation
• B. PaO2/FiO2 < 300 with bilateral infiltrates not due to cardiac failure; ventilatory support with low tidal volume, manage infection/sepsis
• C. PaO2/FiO2 < 100; high tidal volume ventilation
• D. ARDS is not applicable in obstetrics

Answer: (B)

ARDS in obstetrics is defined by acute onset hypoxemic respiratory failure with a PaO2/FiO2 ratio ≤300, accompanied by bilateral infiltrates on imaging that are not fully explained by cardiac failure or fluid overload. In pregnancy, the goal is to support oxygenation while protecting the lungs from further injury, since maternal oxygen delivery directly affects fetal well-being. The best approach matches this definition and management: a PaO2/FiO2 ratio under 300 with bilateral infiltrates not due to cardiac failure, plus ventilatory support using low tidal volumes to minimize volutrauma and adjust PEEP as needed, along with treating any underlying infection or sepsis. The other options don’t fit: unilateral infiltrates contradict the bilateral edema pattern of ARDS, a very low PaO2/FiO2 with high tidal volumes promotes lung injury, and ARDS can and does occur in pregnancy, so saying it’s not applicable is incorrect.

ARDS in obstetrics is defined by acute onset hypoxemic respiratory failure with a PaO2/FiO2 ratio ≤300, accompanied by bilateral infiltrates on imaging that are not fully explained by cardiac failure or fluid overload. In pregnancy, the goal is to support oxygenation while protecting the lungs from further injury, since maternal oxygen delivery directly affects fetal well-being. The best approach matches this definition and management: a PaO2/FiO2 ratio under 300 with bilateral infiltrates not due to cardiac failure, plus ventilatory support using low tidal volumes to minimize volutrauma and adjust PEEP as needed, along with treating any underlying infection or sepsis. The other options don’t fit: unilateral infiltrates contradict the bilateral edema pattern of ARDS, a very low PaO2/FiO2 with high tidal volumes promotes lung injury, and ARDS can and does occur in pregnancy, so saying it’s not applicable is incorrect.