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Question 1

What other drug can be used for an asthma attack in addition to SABA & ipatropium?

Answer 1

I.v. steroids - hydrocortisone (reduce airway inflammation)

Question 2

What FEV1:FVC ratio would be indicative of obstructive airway disease?

Answer 2

Less than 0.7/70%

Question 3

What would be the difference between asthma and COPD in FEV1 after using a bronchodilator?

Answer 3

More than 12% improvement with a bronchodilator (asthma)

Question 4

How would you describe pneumonia on an x-ray?

Answer 4

Opacification

Question 5

Why does pneumonia cause hypoxaemia?

Answer 5

Ventilation perfusion mismatch

Question 6

Why could pneumonia cause a metabolic acidosis rather than a respiratory acidosis? What systemic signs would be present?

Answer 6

Septic shock causes lactic acidosis (accompanied with high HR & low BP)

Question 7

What type of immunity develops following exposure to the TB bacillus?

Answer 7

Cell mediated immunity

Question 8

What giant cell is associated with TB?

Answer 8

Langhans giant cell

Question 9

How would you describe TB on a CXR?

Answer 9

Patchy opacification / Opacification with cavitation

Question 10

What area of the lung does post primary TB usually occur?

Answer 10

Upper lung zone

Question 11

How would you diagnose active TB?

Answer 11

TB on sputum smear/culture
Nucleic acid amplification test on sputum sample

Question 12

Why is non-compliance an issue with TB treatment and how can we solve this?

Answer 12

6 months of abx (patient feels better within few weeks so stops taking them)

Directly Observed Treatment

Question 13

Why does a baby with Respiratory distress syndrome of the newborn find respiration difficult?

Answer 13

1. Surfactant reduces the surface tension of the fluid lining the alveoli
2. No surfactant means higher surface tension of the fluid which reduces lung compliance
3. lungs are harder to expand/more stiff due to reduced compliance/increased elastic recoil

Question 14

Why does NRDS cause hypoxaemia?

Answer 14

Ventilation-perfusion mismatch
(poorly ventilated, collapsed alveoli still perfused)

Question 15

How could a bronchial carcinoma cause left vc paralysis?

Answer 15

Left RLN descends into the thorax, winds around the aortic arch and travels back up to the larynx

Question 16

Describe the cough reflex

Answer 16

1. Deep inspiration following closure of glottis
2. Strong contraction of the expiratory muscles
3. Sudden opening of the glottis causes an explosive discharge of air

Question 17

Why does the cough reflex become less effective following a L RLN palsy?

Answer 17

Glottis unable to fully adduct, so muscle contraction cannot build up intrapulmonary pressure

Question 18

How would you describe a tumour on CXR?

Answer 18

Solitary mass

Question 19

What are some complications with spread of a bronchial carcinoma?

Answer 19

Paralysis of left hemidiaphragm due to phrenic nerve palsy (breathlessness)
Pneumonia distally to tumour
Pericardial effusion

Question 20

At the end of expiration what is the pleural pressure in relation to atmospheric pressure and why?

Answer 20

Below atmospheric pressure

Inward elastic recoil of lung vs outward recoil of the chest wall

Question 21

Why does air enter the pleural cavity in a pneumothorax?

Answer 21

1. Opening in the parietal/visceral pleura
2. Pleural cavity can communicate with the atmosphere
3. Air enters the pleural cavity down the pressure gradient until pleural pressure equilibrates with the atmospheric pressure

Question 22

Why does the lung collapse in a pneumothorax?

Answer 22

1. Pleural seal is broken
2. Lung is no longer adhered to chest wall
3. Inward elastic recoil of the lung is no longer counter balanced by chest elastic recoil
4. Lung collapses towards hilum

Question 23

What features of a patient history favour COPD rather than asthma?

Answer 23

Older
Constant breathlessness
Chronic rather than triggers
Productive cough vs dry asthma cough
No past of allergy
Smoker history

Question 24

What is the axis for a volume loop?

Answer 24

Flow and Volume
COPD has scooped/reduced expiration

Question 25

What clinical signs are associated with hypercapnia?

Answer 25

Warm hands & bounding pulse (peripheral vasodilatoin)
Flapping tremors (CNS impairment)
Drowsiness/confusion (CNS impairment)

Question 26

Causes of chronic cough?

Answer 26

COPD
Asthma
ACE-I induced
GORD

Question 27

Why does oxygen therapy cause hypercapnia to worsen? (V-Q mismatch)

Answer 27

1. Oxygen reduces the pulmonary vasoconstriction
2. Diverting blood to poorly ventilated alveoli instead of well ventilated alveoli
3. So worsens V-Q mismatch

Question 28

Why does oxygen therapy cause hypercapnia to worsen? (Haldane effect)

Answer 28

1. Oxygenated Hb has less affinity for CO2
2. Oxygen therapy increases oxygenated Hb levels
3. So more CO2 released in blood

Question 29

What adaptions are made with chronic hypercapnia with reference to Henderson-Hasselbach equation?

Answer 29

Central chemoreceptors:
1. ^CO2 across BBB
2. Shifts equation to R to lower pH

CNS:
1. Choroid plexus increases reabsorption of HCO3-
2. Pushing equation to L to restore pH

Renal:
1. Kidneys increase reabsorption of HCO3- and excrete H+
2. Pushing equation to L to restore pH

Question 30

How would you describe a pleural effusion on CXR?

Answer 30

1. Opacification with meniscus
2. Loss of hemidiaphragm/costo-phrenic/cardio-phrenic angles

Question 31

How can damage to the intercostal artery be avoided in a pleural aspiration?

Answer 31

Insert needle above the rib to avoid artery which runs along the lower border of each rib

Question 32

How can congestive HF result in a pleural effusion?

Answer 32

Increased hydrostatic pressure at the venous end of the capillaries of the parietal pleura
More fluid leaves the capillary

Question 33

What is the treatment for TB?

Answer 33

RIPE
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol