American Board of Internal Medicine (ABIM) Certification Practice Exam

What is an important criterion for a successful spontaneous breathing trial in patients requiring mechanical ventilation?

1. Ability to tolerate a trial for 30 minutes

2. Respiration rate of less than 40/min

3. Oxygen saturation of 85% or more

4. Stable heart rate above 80 bpm

The correct answer is: Ability to tolerate a trial for 30 minutes

The criterion of being able to tolerate a spontaneous breathing trial for 30 minutes is fundamental because it assesses a patient’s readiness to wean off mechanical ventilation. During this time, healthcare providers monitor the patient's ability to breathe independently without the assistance of a ventilator. Successfully completing a trial for this duration suggests that the patient can maintain adequate ventilation and oxygenation without requiring mechanical support, indicating that they are likely ready for extubation. The duration of 30 minutes is a practical threshold that helps indicate whether the patient can sustain a spontaneous breathing effort. If a patient can manage this period without signs of respiratory distress or failure, it provides confidence in their respiratory functional capacity and stability. It is, therefore, a critical marker in the weaning process from mechanical ventilation.