Breathing

Question 1

What are the applications of flexible bronchoscopy?

Answer 1

Therapeutic and Diagnostic

1. visualisation of pathology
2. sampling eg Bronchoalveolar lavage
3. Difficult intubations
4. Direct opening eg retrieval or stenting

Question 2

Why might you pick rigid vs flexible bronchoscopy?

Answer 2

Rigid allows for greater suction and more instrumentation

Question 3

What is Tidal Volume? and roughly what value is it?

Answer 3

Tidal Volume = volume in and out in one cycle

Roughly 7ml/kg ~500ml

Question 4

What are inspiratory and expiratory reserve volumes?

Answer 4

This is the volume above and below quiet respiration and tidal volume
IRV is around 3L
ERV is around 1.3L

Question 5

What is the Inspiratory Capacity?

Answer 5

Inspiratory Capacity = Tidal Volume + Inspiratory Reserve Volume

Question 6

What is Vital Capacity?

Answer 6

Vital Capacity = Tidal Volume + both inspiratory and expiratory reserve volumes

Question 7

What is Residual Volume?

Answer 7

Residual Volume = gas remaining after maximum expiration

Question 8

What is Total Lung Volume?

Answer 8

Total Lung Volume = Vital Capacity + Residual Volume

Question 9

What is Function Residual Capacity? and what increases it?

Answer 9

Functional residual capacity = Expiratory reserve + respiratory volume ~3L
This is increased in:
1. COPD/Asthma (obstructive)
2. PEEP eg CPAP

Question 10

How do you differentiate obstructive vs restrictive lung disease

Answer 10

Use spirometry:
Obstructive: FEV1/FVC < 0.8
Restrictive: FEV1/FVC > 0.8

Question 11

What is atelectasis?

Answer 11

Atelectasis is collapse (loss of gas) in any section of lung

Question 12

What is absorption atelectasis?

Answer 12

Oxygen is absorbed more readily than nitrogen

over oxygenation causes collapse

Question 13

What are the causes of post-op atelectasis?

Answer 13

1. Increased secretions
2. Pain causing reduced tidal volume
3. Over oxygenation and absorption atelectasis
4. Patient: High BMI, Smoking, COPD

Question 14

What is Bronchiectasis?

Answer 14

Irreversible dilatation of the bronchi (due to infection) and impaired clearance of secretions
Presents clinically as obstructive

Question 15

What are the common causes of bronchiectasis and how can they be categorised?

Answer 15

Congenital:
1. Cilliary Dyskinesia (Kartagener’s)
2. Cystic Fibrosis (most common)
3. Immunodeficiency (multiple infections)
Acquired:
1. Repeated acute and chronic inflammation (eg infection)
2. Obstruction (eg tumours/foreign body)
3. Others eg aspergillosis, Rheumatoid, UC

Question 16

What is the management of bronchiectasis?

Answer 16

1. Treat underlying cause (eg infections/airway obstruction)
2. Medical (eg bronchodilators and steroids)
3. Symptomatic (eg physio)
4. Definitive ( eg surgery - RARE)

Question 17

What is the definition of pneumonia?

Answer 17

Inflammatory condition of the lung, characterised by exudative consolidation

Question 18

What are the phases of lobar pneumonia?

Answer 18

1. Acute congestion (to day 2): hard, firm, lots of exudate
2. Red hepatisation (to day 4): firm, red, consolidated with red cells and inflammatory cells
3. Grey hepatisation (to day 6): firm, grey, consolidated with fibrin
4. Resolution (day 8 to 3 weeks): macrophages break down exudate

Question 19

What are the common complications of pneumonia?

Answer 19

1. Type I respiratory failure
2. Pleuritis (extensive adhesions)
3. Pleural effusion
4. Empyema
5. Abscess (local or systemic)
6. Sepsis

Question 20

What is the definition of ARDS?

Answer 20

1. Respiratory failure + persistent inflammatory disease

2. Causes: reduced compliance, hyperaemia, pulmonary oedema

Question 21

What are the phases of ARDS?

Answer 21

1. Inflammatory: local complement, immune cells, increased permeability
2. Proliferative: increased dead space with fibrosis and scarring
3. Progressive: extensive fibrosis and loss of alveolar structure

Question 22

Which cells produce surfactant?

Answer 22

Type 2 Pneumocytes

Question 23

How do you manage ARDS?

Answer 23

1. Manage initial insult
2. Nutritional Support
3. Mechanical ventilation to eliminate CO2
4. Smaller tidal volumes
5. Prone positioning
6. Fluid management
7. Nitric Oxide for vasodilatation

Question 24

Define Flail Chest

Answer 24

3 or more ribs broken in 2 or more places

Question 25

How does a flail segment present?

Answer 25

Paradoxical movement during respiratory cycle | Causes reduced tidal volumes and atelectasis

Question 26

What is a sucking chest wound?

Answer 26

Open chest wall injury larger than 2/3rds of trachea. air preferentially enters via this. causes a large tension pneumothorax treated with a flutter valve

Question 27

What are the risk factors for DVT?

Answer 27

``` Intrinsic: 1. Age 2. Cancer 3. Dehydration and sepsis 4. Haematological 5. Previous thrombotic events 6. Endocrine eg COCP Surgical: 1. Stasis from major surgery and immobilisation ```

Question 28

Where do DVTs usually occur?

Answer 28

Deep veins of the calves | venous plexus in soleus.

Question 29

What are you likely to see in obs and ABG of a PE?

Answer 29

hypoxia - V/Q mismatch due to decreased blood flow hypocarbia - due to hyperventilation tachycardia - due to right sided ventricular strain

Question 30

what is the treatment of a PE?

Answer 30

1. LMWH 2. Anticoagulation 3. Thrombolytic agents 4. Catheter dislodge or surgery

Question 31

What are the normal ranges of PaO2 and PaCO2?

Answer 31

PaO2: 10.6 - 13.3kPa PaCO2: 4.7 - 6.0kPa

Question 32

How do you classify Respiratory Failure?

Answer 32

Type 1: low O2 - V/Q mismatch. This causes increased CO2 which leads to hyperventilation. PaO2 <8kPa Type 2: ventilatory failure. alveolar hypoventilation causing hypercarbia. PaCO2 > 6.7kPa. Mixed = Type 1 causing tiredness and leading to type 2

Question 33

Examples of Type 1 Respiratory failure?

Answer 33

Shunting: Eisonmenger's, congenital shunt V/Q Mismatch: PE, Pneumonia, Pneumothorax, Oedema, Bronchiectasis, Fibrosis

Question 34

Examples of Type II Respiratory failure?

Answer 34

Lung parenchyma issues: COPD, asthma, fibrosis, OSA Neuro issues: stroke, head injury, drugs Neuromuscular: MND, guillan barré

Question 35

Outline the equipment and steps for a surgical chest drain.

Answer 35

Equipment: sterile pack - drapes, swab. Needles, scalpel. curved clamps, suture kit. Local anaesthetic. chest drain, tubing and drainage. Procedure: 1. Mark: based on CXR or 5th IC space 2. prep and drape clavicle to pelvis 3. Local: anaesthetic lidocaine layer by layer to pleura 4. Incision and blunt dissection 5. secure the incision 6. insert chest drain 7. connect to underwater drainage and check for bubbling.