LP 4: Respiratory Failure

Question 1

What happens in RF? (Common 3)

Answer 1

1) Failure of gas exchange
2) Inability to maintain normal blood gases
3) Low PaO2
(Can have rise of PaCO2)

Question 2

What is T1 RF and causes?

Answer 2

Hypoxia

C: V/Q mismatch due to alveolar hypoventilation, high altitude, shunt and diffusion impairment

Question 3

What is T2 RF and causes?

Answer 3

Hypoxia and Hypercapnia

C: Inadequate Alveolar Vent as V breathing effort & SA and NM problems

Question 4

What effect does hypoxia have on P-V’s?

Answer 4

Vasoconstricts, so redirects blood to O2 rich alveoli

Question 5

How does hypoxia cause Respiratory Alkalosis?

Answer 5

Leads to Hyperventilating, as try to inhale more O2, so lose lots of CO2

Question 6

How does Hypoxia affect systemic vessels?

Answer 6

Vasodilation

Question 7

Why is there a decreased response to Hypoxia and Hypercapnia in an ageing lung?

Answer 7

Lung more vulnerable and decreased awareness so delay in detection of problem

Question 8

What is the respiratory drive?

Answer 8

Determinant of intensity of output of respiratory centres, determines mechanical output of RM

Question 9

Which gas is RD more sensitive to?

Answer 9

Very sensitive to CO2, so is a greater drive, as small change in PaCO2 leads to large vent change