American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the recommended mode for mechanical ventilation to minimize risk of lung injury?

1. Pressure-controlled ventilation

2. Volume-controlled continuous mandatory ventilation

3. Spontaneous ventilation

4. Assist-control mode

The correct answer is: Volume-controlled continuous mandatory ventilation

Volume-controlled continuous mandatory ventilation is considered the recommended mode for mechanical ventilation to minimize the risk of lung injury, particularly in patients with conditions like Acute Respiratory Distress Syndrome (ARDS). This ventilation mode delivers a preset volume of air with each breath, ensuring that the patient receives adequate tidal volume while maintaining consistent minute ventilation. In the context of lung protection, the key advantage of volume-controlled ventilation is its ability to set and limit the tidal volume, which helps to avoid overdistension of the alveoli. This is crucial because high tidal volumes can contribute to ventilator-induced lung injury (VILI) by causing barotrauma and volutrauma. By using this mode, clinicians can manage ventilation carefully, ensuring that airway pressures remain within safe limits and minimizing the risk of further lung damage. In contrast, other modes such as pressure-controlled ventilation may inadvertently allow for variable tidal volumes depending on lung compliance and resistance. Spontaneous ventilation might not provide adequate control and consistency in oxygen delivery for patients in critical care, especially those not able to maintain sufficient ventilation on their own. Assist-control mode, while improving patient-ventilator synchrony, can also lead to higher tidal volumes if the patient's respiratory efforts trigger larger volumes than intended, posing a similar risk to