Respiratory Failure and ARDS

Question 1

What are the three types of respiratory failure?

Answer 1

Hypoxemic
Hypercapneic
Mixed

Question 2

What causes hypoxemic respiratory failure?

Answer 2

Inadequete oxygenation from impaired transport. Includes alveolar filling (edema, pneumonia, hemorrhage, ARDS) and extra-alveolar processes (pulmonary vascular disease and shunts)

Question 3

What causes hypercapneic respiratory failure?

Answer 3

Inadequete ventilation from obstructive or restrictive lung disease or central hypoventilation.

Question 4

What cause mixed respiratory failure?

Answer 4

Diseases like emphysema which impair both transport and ventilation.

Question 5

How does hypoxemic failure appear on blood gas?

Answer 5

Low PaO2, high A-a gradient.

Question 6

What are the four main variable for mechanical ventilation?

Answer 6

FiO2, PEEP, RR, TV.
(FiO2 and PEEP determine oxygenation)
(RR and TV determine ventilation)

Question 7

How is ARDS defined?

Answer 7

1) Diffuse bilateral infiltrates

2) PaO2/FiO2

Question 8

What are common causes of ARDS?

Answer 8

Sepsis, pancreatitis, trauma, aspiratin, tranfusion

Question 9

How is ARDS managed?

Answer 9

Low tidal volume ventilation, some prone positioning