Acute Respiratory Failure Flashcards

By the Berlin definition, ARDS is characterized by bilateral infiltrates and a PaO2/FiO2 ratio of:

Answer: ≤ 300 mmHg with PEEP ≥ 5

ARDS requires a P/F ratio ≤ 300 with at least 5 cm H2O of PEEP or CPAP.

The Berlin criteria require that ARDS-related respiratory failure is NOT fully explained by:

Answer: Cardiac failure or fluid overload

Hydrostatic edema from cardiac failure or volume overload must be excluded as the primary cause.

Which lung-protective tidal volume target is recommended for a patient with ARDS?

Answer: 6 mL/kg of predicted body weight

Low tidal volume ventilation at 6 mL/kg predicted body weight reduces ventilator-induced lung injury.

In ARDS lung-protective ventilation, plateau pressure should generally be kept below:

Answer: 30 cm H2O

Keeping plateau pressure < 30 cm H2O limits alveolar overdistension and barotrauma.

Which positioning intervention improves oxygenation and mortality in moderate-to-severe ARDS?

Answer: Prone positioning

Prone positioning improves V/Q matching and recruits dorsal lung regions, reducing mortality in severe ARDS.

Permissive hypercapnia during ARDS ventilation is acceptable as long as:

Answer: pH remains within a tolerable range (generally > 7.20)

Allowing CO2 to rise is tolerated to protect the lungs, provided pH stays in an acceptable range.

What is the primary pathophysiologic hallmark of the exudative phase of ARDS?

Answer: Increased alveolar-capillary membrane permeability with protein-rich edema

Diffuse alveolar damage increases capillary permeability, flooding alveoli with protein-rich fluid.