FN: Respiratory failure

Question 1

TYpe 1

Answer 1

PaO2

Question 2

Type 2

Answer 2

PaO2 6kPA

Alveolar hypoventilation ±V/Q mismatch

Question 3

Causes

Answer 3

V/Q mismatch
Alveolar hypoventilation
Diffusion failure

Question 4

V/Q mismatch (raised A-a gradient)

Answer 4

Vascular:
1. PE
2. PHT
3. Pulmonary shunt (R--> L)
Asthma (early0
Pneumothorax
Atelectasis

Question 5

Alveolar Hypoventilation

Answer 5

Obstructive vs restrictive

Question 6

Obstructive

Answer 6

COPD
Asthm
Bronchiectasis
Bronchiolitis
Intra- and Extra-thoracic (Ca, LN,, Epiglottis)

Question 7

Restrictive

Answer 7

reduced drive: CBS sedation , trauma, tumour
NM disease: cervical cord lesion, polio, GBS, MG
Chest: flail, kyphocoliosis, obesity
Fluid and fibrosis

Question 8

Diffusion failure

Answer 8

Fluid:

1. Pulmonary oedema
2. Pneumonia
3. Infarction
4. blood

Fibrosis

Question 9

A-a gradient

Answer 9

PAo2 = (95 x FiO2) - (PaCo2/0.8)

raised (PAO2 - PaO2) suggest lun pathology

Question 10

Clinical features of hypoxic acute

Answer 10

Dyspnoea
Agitation
Confusion
cyanosis

Question 11

Clinical features of hypoxia chronic

Answer 11

Polycythaemia
PHT
Cor pulmanle

Question 12

Hypercapnoea symptoms

Answer 12

Headache
Flushing and peripheral vasodilation
Flap
Confusion - coma

Question 13

Management

Answer 13

Rx the underlying cause

Question 14

Type 1 management

Answer 14

Give oxygen to maintian SpO2 94-98%

Assisted ventilation if PaO2

Question 15

Type 2

Answer 15

Controlled O2 therapy @ 24% Oxygen aiming for SpO2 88-92% and a PaO2 >8kPa
Check ABG fter 20 min
1. If PaCO2 steady or lower can raised FiO2 if neccessary
2. If PaCO2 raised >1.5 kPa and pt. still hypoxic, consider NIV or respiratory stimulant (e.g. doxapram)

Question 16

Oxygen therapy principles

Answer 16

Critcal patients high flow immediately

Targeted to reach sats of 98 + unless COPD

Question 17

PAtients at risk of hypercapnic resp failure management

Answer 17

1. Start Oxygen therapy at 24% and do an ABG - blud venturi @2-4l/min
   Clinically: reduced RR with Oxygen may be a useful sign
   If PCI2 6kPA: maintain target SpO2

Question 18

Mechanisms of oxygen delivery

Answer 18

Nasal specs
Simple face mask
Nonrebreathe
Venturi mask

Question 19

Nasal prongs dosage

Answer 19

1-4L/min = 24-40% O2

Question 20

Non-rebreathe mask

Answer 20

REservoir bag allows delivery of high concentrations of O2: 60-90% at 10-15L

Question 21

Venturi mask

Answer 21

yellow: 5%
White; 8%
Blue: 24%
Red: 40%
Green:60%