Mechanical Ventilation Flashcards

The lung-protective ventilation strategy for ARDS recommends tidal volumes of:

Answer: 6 mL/kg ideal body weight

The ARDSNet protocol demonstrated improved survival with tidal volumes of 6 mL/kg IBW compared to conventional 12 mL/kg volumes.

Which waveform is characteristic of volume-controlled, constant-flow ventilation?

Answer: Square (constant) flow waveform

Volume control with constant flow produces a square (rectangular) flow waveform, resulting in a linearly increasing pressure waveform.

A patient's peak airway pressure suddenly increases with no change in plateau pressure. This suggests:

Answer: Increased airway resistance (e.g., bronchospasm, secretions)

A rise in peak pressure with unchanged plateau pressure indicates increased airway resistance because resistance affects dynamic (peak) but not static (plateau) pressure.

Permissive hypercapnia in ARDS management allows PaCO2 to rise to reduce:

Answer: Barotrauma and volutrauma from aggressive ventilation

Permissive hypercapnia accepts elevated PaCO2 to enable lower tidal volumes and pressures, minimizing ventilator-induced lung injury.

Which mode is most appropriate for weaning a patient from mechanical ventilation?

Answer: Pressure support ventilation (PSV) with gradually reduced support

PSV weaning allows clinicians to progressively reduce inspiratory support as the patient's spontaneous breathing strength improves, facilitating a smooth transition to extubation.

Synchronized intermittent mandatory ventilation (SIMV) delivers mandatory breaths that are:

Answer: Synchronized to patient inspiratory effort when present

SIMV attempts to time mandatory breaths to coincide with the patient's own inspiratory effort to reduce patient-ventilator asynchrony.