Acute Resp

Question 1

Differentiate type 1 and type 2 respiratory failure. Which is focal and which is global?

Answer 1

Type 1: hypoxia. Focal. V/Q (ventilation/ perfusion) mismatch
Type 2: Hypoxia and hypercapnia, global, alveolar hypoventilation.

Question 2

Give 7 causes of Type 1 respiratory failure.

Give 5 causes of Type 2 respiratory failure.

Answer 2

Type 1:

• Acute asthma
• Atalectassis
• ARDS
• Pneumonia
• Pneumothorax
• Pulmonary oedema
• PE

Type 2:

• Acute severe asthma
• COPD
• Upper airway obstruction
• Neuropathies: GBS, MND
• Drugs (opiates)

Question 3

Give 3 risk factors for pneumothorax

Answer 3

• Male
• Smoking
• Marfanoid habitus (not strictly those with Marfan’s)

Question 4

Give 2 classifications of pneumothorax.

What type would be expected in a young person? What would be the cause?

Answer 4

• Traumatic vs spontaneous

- Primary vs secondary. Primary usually young healthy person. Due to pleural blebs or pleural adhesions forming.

Question 5

Give 3 signs of lung compression in tension pneumothorax.

Give 2 signs of mediastinal shift in tension pneumothorax.

Answer 5

Lung compression:

• Severe dyspnoea
• Tracheal deviation away from lesion
• Silent chest, hyperresonance, reduced expansion on lesioned side.

Mediastinal shift

• Hypotension
• Tachycardia

Tension pneumothorax is a one way valve, the pneumothorax only gets larger.

Question 6

What is the immediate management for a tension pneumothorax

Answer 6

• Wide bore cannula inserted into 2nd Intercostal space, mid-clavicular line. Orange or grey cannula.

Place just above 3rd rib to avoid neuromuscular bundle of 2nd rib.

Question 7

Outline the treatment for primary and secondary pneumothorax

Answer 7

Primary:

• If no SOB or <2cm: discharge
• > 2cm/ SOB: Needle aspirate then observe with O2
• If unsuccessful chest drain.

Secondary:

• If no SOB or <1cm: observe with O2
• 1-cm: Needle aspirate and observe. If unsuccessful chest drain.
• > 2cm or SOB: Chest drain.

Question 8

What is the mnemonic for patients at risk of PE?

What investigation is needed for a suspected PE?

Answer 8

CT S’il Vous Plait- here are the trickier examples.

• Cancer/ factor C deficiency
• Trauma
• Factor S deficiency
• Virchow’s triad, Factor V Leiden
• Pregnancy

Investigation is a CTPA.

Question 9

Which scoring system is used to investigate a PE?

What are the score dependent investigations to be carried out after?

Answer 9

Well’s score:

• > /= 4, CTPA, high risk
• <4: D-dimer, low risk

Question 10

Give 3 signs of an acute massive PE: sudden complete occlusion of pulmonary artery.
Give 3 ECG changes of an acute massive PE

Answer 10

• Collapse
• Central crushing chest pain
• Severe dyspnoea
• S1Q3T3 pattern: indicative of RV strain. Prominent S Wave in lead I. Q wave and inverted T wave in lead III
• RAD- right axis deviation
• RBBB

Question 11

Give 3 signs of acute small PE: sudden incomplete occlusion of pulmonary artery.

Give 1 ECG change of an acute small PE

Answer 11

• Pleuritic chest pain
• Haemoptysis
• Dyspnoea
• Sinus tachycardia

Question 12

Give 1 sign of chronic PE: chronic occlusion of pulmonary vasculature.

Give 1 CXR finding with a high predictive value for PE, even though it only occurs in 10% of cases.

Answer 12

• Exertional dyspnoea.

- Westermark sign. Shows translucent region distal to occluded pulmonary artery.

Question 13

In the prevention of PE, give 1 mechanical and 1 pharmacological prevention step.

Answer 13

• Mechanical: thrombosis-embolic deterrent stockings.
• Pharmacological: Low molecular weight heparin- tinzaparin.

“TEDs and Tinz”

Question 14

What is the key question for the management of PE? What are the conclusions of a positive or negative answer?

Answer 14

Is patient haemodynamically stable- SBP >90. Worried about low blood pressure

Yes: Sub-acute/ chronic PE
No: Massive PE

Question 15

Give the 2 management steps and 2 medications for a sub-acute/ chronic PE (haemodynamically stable)

Answer 15

• Respiratory support
• Anticoagulation

Anticoagulants:

• Fondaparinux/ Heparin for 5 days
• Warfarin for 3 months

Question 16

Give the 3 management steps and 3 medications for massive PE (not haemodynamically stable)

Answer 16

• Respiratory support
• 1st line: thrombolysis
• 2nd line: Embolectomy

IV thrombolytics:

• Alteplase
• Streptokinase
• rt-PA

Question 17

What is the pathophysiology of ARDS

Answer 17

ARDS is a form of hypoxaemic acute lung injury.

• Body responds with profound inflammatory response
• Increase in vascular permeability
• Fluid enters lungs in similar way to pulmonary oedema
• Build up of fluid in lungs increases pressure in alveoli
• Alveolar collapse reduces surface area for gas exchange, increases diffusion distance.

ARDS = non-cardiogenic pulmonary oedema.

Question 18

Give a simplified version of the Berlin criteria for the definition of ARDS

Give 3 investigations for ARDS.

Answer 18

A- Alternative cause to Pulmonary oedema.
R- Rapid onset <1 week
D- Dyspnoea
S- similar on CXR: ABCDE

• ABG (PF ratio)
• CXR/ CT
• Echocardiogram

ABCDE: Alveolar oedema (batwing), Kerley B lines, Cardiomegaly, dilated upper lobe vessels, pleural effusion.