Certified Medical-Surgical Registered Nurse Practice Exam

In a patient with ARDS on mechanical ventilation, what intervention is likely to improve Pao2 without raising Fio2?

1. Time-cycled ventilation.

2. Volume-cycled ventilation.

3. Pressure support.

4. PEEP.

The correct answer is: PEEP.

In a patient with Acute Respiratory Distress Syndrome (ARDS) who is on mechanical ventilation, the use of Positive End-Expiratory Pressure (PEEP) is particularly beneficial for improving oxygenation. PEEP works by maintaining a certain level of pressure in the airways at the end of expiration, which prevents alveolar collapse and increases functional residual capacity. This recruitment of collapsed or under-inflated alveoli allows for better gas exchange and improved PaO2 levels without the need to increase the fraction of inspired oxygen (FiO2). Using PEEP can enhance oxygenation in ARDS patients while minimizing the risk of oxygen toxicity that can occur with high FiO2 levels. In clinical practice, applying PEEP helps optimize lung volume and improve ventilation-perfusion matching, subsequently leading to enhanced oxygen delivery to the bloodstream. Therefore, implementing PEEP is a key strategy in managing ARDS patients on mechanical ventilation to improve oxygenation effectively.