Acute Respiratory/Distress

Question 1

What is Acute Respiratory Distress syndrome defined as?

Answer 1

Defined as an acute condition characterized by bilateral pulmonary infiltrates and severe hypoxemia (PaO2/FiO2 ratio < 200) in the absence of evidence for cardiogenic pulmonary oedema

Question 2

What are some causes of Acute Respiratory Distress syndrome?

Answer 2

• Sepsis
• Direct lung injury
• Trauma
• Acute pancreatitis
• Long bone fracture or multiple fractures (through fat embolism)
• Head injury (causes sympathetic nervous stimulation which leads to acute pulmonary hypertension)

Question 3

What are clinical features of Acute Respiratory Distress syndrome?

Answer 3

• Acute dyspnoea and hypoxaemia hours/days after event
• Multi organ failure
• Rising ventilatory pressures

Question 4

How is Acute Respiratory Distress managed?

Answer 4

• Treat the underlying cause
• Antibiotics (if signs of sepsis)
• Negative fluid balance i.e. Diuretics
• Recruitment manoeuvres such as prone ventilation, use of positive end expiratory pressure
• Mechanical ventilation strategy using low tidal volumes, as conventional tidal volumes may cause lung injury (only treatment found to improve survival rates)

Question 5

What are key indications for Non-Invasive Ventilation?

Answer 5

• COPD with respiratory acidosis pH 7.25-7.35*
• Type II respiratory failure secondary to chest wall deformity, neuromuscular disease or obstructive sleep apnoea
• Cardiogenic pulmonary oedema unresponsive to CPAP
• Weaning from tracheal intubation

Question 6

What is anaphylaxis?

Answer 6

-SERIOUS allergic reaction

Question 7

What causes Anaphylaxis?

Answer 7

• Sensitised individual exposed to specific antigen
• Commonly from insects bites/ stings, food, medications

Question 8

What is the immunological respose to expose to the specific antigen?

Answer 8

• IgE exposed to antigen
• Activation of mast cell & basophils
• Release of histamine leading to angiodema and widespread vasodilation

Question 9

What are the symptoms to Anaphylaxis?

Answer 9

• Pruritus
• Urticaria & Angioedema
• Hoarseness
• Stridor & Bronchial obstruction
• Wheeze & chest tightness from bronchospasm

Question 10

How is Anaphylaxis managed?

Answer 10

• Remove trigger, maintain airway
• 100% O2
• Intramuscular adrenaline 0.5 mg (Repeat every 5 mins as needed to support CVS)
• IV hydrocortisone 200mg
• IV chlorpheniramine 10 mg
• If hypotensive: lie flat and fluid resuscitate
• Treat bronchospasm: NEB salbutamol
• Laryngeal oedema: NEB adrenaline

Question 11

How is Massive Haemoptysis classified?

Answer 11

>240mls in 24 hours OR >100mls / day over consecutive days

Question 12

What is the management of Massive Haemoptysis?

Answer 12

• ABCDE
• Lie patient on side of suspected lesion (if known)
• Oral Tranexamic Acid for 5 days or IV
• Stop NSAID’s / aspirin / anticoagulants
• Antibiotics if any evidence of respiratory tract infection
• Consider Vitamin K
• CT aortogram – interventional radiologist may be able to undertake bronchial artery embolisation