Mechanical Ventilation Flashcards

High-frequency oscillatory ventilation (HFOV) uses:

Answer: Very small tidal volumes at very high rates (3–15 Hz)

HFOV delivers very small tidal volumes (often less than anatomical dead space) at very high frequencies, maintaining lung recruitment while minimizing pressure swings.

The spontaneous breathing trial (SBT) is used to assess:

Answer: Patient readiness for extubation

An SBT evaluates whether a patient can sustain adequate ventilation and oxygenation without mechanical ventilator support before extubation is attempted.

The rapid shallow breathing index (RSBI) predicts weaning success. A favorable RSBI is:

Answer: Less than 105 breaths/min/L

An RSBI below 105 (f/VT ratio) is associated with successful weaning; values above 105 suggest the patient is unlikely to tolerate extubation.

Which alarm condition most urgently requires immediate assessment and intervention?

Answer: Apnea alarm with absent patient effort

An apnea alarm with absent patient effort indicates the patient is not breathing, requiring immediate assessment and intervention to prevent hypoxia.

Endotracheal tube cuff pressure should be maintained at:

Answer: 20–30 cmH2O

ETT cuff pressure of 20–30 cmH2O (or 15–22 mmHg) provides an adequate seal to prevent aspiration while avoiding mucosal ischemia.

Inverse ratio ventilation (IRV) is characterized by:

Answer: Inspiratory time equal to or longer than expiratory time (I:E ≥ 1:1)

IRV reverses the normal I:E ratio so inspiration is as long as or longer than expiration, recruiting alveoli and improving oxygenation in severe ARDS.