Ventilation

Question 1

CPAP stands for?

Answer 1

Continuous positive airway pressure

Question 2

BiPAP stands for?

Answer 2

Biphasic positive airway pressure

Question 3

How does CPAP fix a V/Q mismatch?

Answer 3

Increases the ventilation (for the OK Q) by recruiting alveoli for GE

Question 4

Name FIVE uses for CPAP

Answer 4

Cardiogenic APO
CHF
Pneumonia
Sleep Apnoea
Type I respiratory failure

Question 5

What is NIV - non-invasive ventilation?

Answer 5

AKA BiPAP provides both PEEP (what CPAP provides) as well as giving a PUSH of air into the lungs

Question 6

Name FIVE uses for BiPAP.

Answer 6

COPD
Pneumonia
Type II respiratory failure
To PREVENT intubation
To SUPPORT extubation

Question 7

What is TYPE I respiratory failure?

[state FOUR aspects]

Answer 7

HYPOXIC respiratory failure where PaO2 < 60 mmHg with normal PaCO2
MORE common type
Involves fluid filling or alveolar collapse

Question 8

Name THREE causes of Type I respiratory failure.

Answer 8

APO - cardiogenic or non-cardiac
pneumonia
pulmonary haemorrhage

Question 9

What is TYPE II respiratory failure?

Answer 9

HYPERCAPNIC respiratory failure where PaCO2 50 mmHg.

Question 10

Name FOUR causes of Type II respiratory failure.

Answer 10

Drug overdose
Neuromuscular disease
Chest wall abnormalities
Airway diseases (COPD, asthma)

Question 11

What is PEEP? What does it do? What units is it measured in?

Answer 11

Positive End Expiratory Pressure - what remains in the alveoli after exhalation
PEEP keeps the alveoli open.
PEEP is measured in cmH2O

Question 12

In BiPAP, what does the Inspiratory pressure IP do?
What units is IP measured in?
What lung parameter is affected by BiPAP?

Answer 12

IP is the PUSH that accompanies inspiration
IP is measured in cmH2O
IP helps INCREASE tidal volume

Question 13

What tidal volume is aimed for (in ml/kg)?

Answer 13

6-8 ml/kg

Question 14

FiO2 stands for?

What does FiO2 of 1.0 mean?

Answer 14

Fraction of inspired Oxygen.

FiO2 of 1.0 = 100% oxygen.

Question 15

What is the FiO2 of room air?

Answer 15

0.21 or 21%

Question 16

Compare CPAP with BiPAP (or NIV)

Answer 16

CPAP:
high flow O2 + PEEP
Recruits alveoli
corrects V/Q mismatch
Type I RF
NIV:
IP + PEEP
increases TV & decreases CO2
Type II RF

Question 17

How much supplemental Oxygen should be delivered?

Answer 17

Enough to oxygenate the patient:
young & usually fit: 97-100%
older: 94-97%
COPD: 88-92% (hypercapnia)

Question 18

Using nasal cannula, how much oxygen in L/min & as a % is delivered?

Answer 18

2-4 L/min

28-35%

Question 19

Using a hudson mask, how much oxygen in L/min & as a % is delivered

Answer 19

4-6 L/min

35-50%

Question 20

Venturi masks allow for different oxygen delivery - how much

Answer 20

24-60% depending on flow rate

Question 21

When (and why) should you use humidified high flow oxygen?

Answer 21

When they are likely to be on more than 6L for more than 6 hours.
Oxygen is very drying; humidifying it will improve patient comfort.

Question 22

Using a non-rebreather mask, how much oxygen in L/min & as a % is delivered

Answer 22

12-15 L/min

upto 85%

Question 23

For a non-rebreather mask to work properly what THREE conditions must be met?

Answer 23

flow must be 12-15 L/min
mask must be tight fitting
bag must be pre-inflated

Question 24

What flow rate is required for a nebuliser mask

Answer 24

6-8 L/min
too low - insufficient to nebulise
too high - back flow counter productive

Question 25

How does CPAP differ from BiPAP?

Answer 25

CPAP only offers PEEP

BiPAP offers PEEP and IP