Session 1- Clinical Application in Ventilation and Lung Mechanics

Question 1

Atelactasis

Answer 1

Complete or partial lung collapse

Impaired pulmonary surfactant production

Question 2

Interstitial lung disease

Answer 2

Lung expansion difficult secondary to stiff lungs from increased collagen in alveolar walls – decreased compliance/increased elastic recoil

Question 3

hypoventilation

Answer 3

Inability to expand chest and ventilate

Question 4

Pneumothorax

Answer 4

Air in the intrapleural space with loss of pleural seal

Question 5

Obstructive lung disease- COPD and asthma

Answer 5

Increase in airways resistance and, in emphysema decreased elastance/elastic recoil secondary to loss elastic fibres – compliance increased but elastic recoil decreased

Question 6

Respiratory distress syndrome new born

Answer 6

Decrease in surfactant leads to increased surface tension and decreased compliance

Question 7

What is COPD

Answer 7

Clinical syndrome characterised by chronic respiratory symptoms with associated pulmonary abnormalities- all conditions share impaired airflow that is not fully reversible

• chronic bronchitis
• emphysema

Question 8

Chronic bronchitis

Answer 8

A disease of the small airways- inflammation in the smaller bronchi and bronchioles- airways chronically inflamed

– Increased air flow resistance– worse on expiration
– Alteration of airway surface tension(increased) predisposing to small airway
collapse - worse on expiration

Question 9

Pathology of chronic bronchitis

Answer 9

• Mucous hypersecretion
• Reduced cilia and impaired function – mucous is not cleared effectively - narrows airways
• Epithelial remodelling - also narrows airways
• Loss of small airways
• Increased airway surface tension - fewer clara cells (less surfactant-like material in airways)

Question 10

What is COPD emphysema

Answer 10

Abnormal permanent enlargement of the air spaces distal to the terminal bronchiole with destruction of alveolar walls

Inflammatory cells accumulate
-release elastases and oxidants which destroy alveolar walls

Reduced elastic recoil

• harder to exhale
• small airways collapse

Question 11

Difference between structure of bronchus and bronchiole

Answer 11

Bronchus has small islands of cartilage and glands in submucosa

Bronchiole has no cartilage or glands

Question 12

How do bronchioles stay open

Answer 12

Radial traction

Question 13

What is radial traction

Answer 13

Outward tugging action Prevents collapse of bronchioles during expiration

Question 14

What is Barrel chest

Answer 14

Increased air flattens diaphragm- cant contract as effectively- impaired inspiration

Question 15

Airway obstruction in COPD

Answer 15

Small airways narrowed through thickened bronchioles periphery wall causes by inflammation and field narrowing asa result of fibrosis

Luminal occlusion by mucus and inflammatory exudate

Question 16

Compression alectasis aetiology

Answer 16

Pressure on alveoli

• air in pleural cavity
• Fluid in pleural cavity
• abdominal obesity
• GI surgery post-opp distension pushing up and compressing alveoli

Question 17

Resorption collapse

Answer 17

is a form of lung collapse that is due to obstruction of the airways supplying a lung segment or lobe
Alveoli collapse

Question 18

What is contained within the interstitium between the alveolus and capillary

Answer 18

Elastin fibres

Collagen

Fibroblasts

Matrix substance

BASEMENT MEMBRANE

Question 19

What is the state of the pulmonary interstitium in pulmonary fibrosis

Answer 19

Thickened which increases diffusion distance for 02 and c02

Impairs gas exchanges

Question 20

Interstitial lung disease lung mechanics

Answer 20

Lung compliance is reduced- lungs re stiff and harder to expand

Elastic recoil of the lungs is increased - he resting lung volume is smaller than normal

Restrictive type of ventilators defect

Question 21

Interstitial lung disease symptoms

Answer 21

– Dry cough
– Dyspnoea on exertion progressing
to at rest
– Fatigue

Question 22

Signs of interstitial lung disease

Answer 22

• decreased lung excursion on palpation
• bi-basal end inspiratory lung crackles

-Finger clubbing - Small pleural effusions

Question 23

In diffuse pulmonary fibrosis will functional residual capacity be reduced or increased

Answer 23

Decreased

Question 24

Functional residual capacity

Answer 24

Volume of air in the lungs at the end of quiet expiration

Question 25

What produces surfactant

Answer 25

Type 2 pneumocytes

Question 26

When is the amount of surfactant surffienct

Answer 26

35-36 weeks

Question 27

Neonatal respiratory distress syndrome

Answer 27

Lac of surfactant in pre term babies

Lung expansion is incomplete
Some alveoli remain collapsed
Lung is stiff
Increased effort is required to breathe

Question 28

Neonatal respiratory distress syndrome signs

Answer 28

Ø Grunting,
Ø Nasal flaring,
Ø Intercostal and subcostal retractions
Ø Rapid respiratory rate (tachypnoea)
Ø Cyanosis

Question 29

In COPD emphysema will FRC at the end of quiet expiration be reduced or increased

Answer 29

Increased

Increased compliance due to low of elastic tissue which means decreased elastic recoil

Question 30

Problem with airflow in emphysematous dominant COPD

Answer 30

• loss of elastic tissue
• increased compliance and reduced elastic recoil
• hyper inflated
• small airways collapse in expiration
• air trapping
• increased FRC

Question 31

Problem with airflow in pulmonary fibrosis

Answer 31

• increase of fibrous tissue
• less compliant
• smaller lungs
• decreased FRC
• no airway obstruction

Question 32

What would h happen if the pleural seal was broken

Answer 32

Collapse

Question 33

What happen s in pneumothorax

Answer 33

• Chest wall or the lung is
breached - tear in parietal or
visceral pleura
• A communication is created
between pleural space and
atmosphere
• Air flows from atmosphere
(higher pressure) à into the
pleural cavity (lower pressure) • Until the pleural pressure =
atmospheric pressure
• The pleural seal is lost
• Lung elastic recoil not
counter-balanced by negative
pleural pressure/chest wall • Lung collapses to unstretched
size
`

Question 34

What is hypoventilation

Answer 34

Failure to breathe rapidly enough or deeply enough