Mechanical Insufflation - Exsufflation (MI-E)

Question 1

What are the typical patient groups who use MI-E?

Answer 1

• Motor neurone disease
• Spinal muscular atrophy
• Muscular dystrophy
• Spinal cord injuries
• Acute exacerbations of chronic lung conditions (where cough is ineffective due to fatigue)
• Post-polio syndrome (still common in Africa, South-East Asia)
• Myasthenia gravis

Question 2

What are some absolute contraindications for MI-E?

Answer 2

• Undrained pneumothorax (can cause it to expand)
• Severe/Uncontrolled bronchospasm
• Head injury with intracranial pressure (ICP) > 25mmHg
• Severe arterial hypotension
• Trache-oesophageal fistula
• Significant haemoptysis

Question 3

What are some relative contraindications for MI-E use?

Answer 3

• Proximal tumour or obstruction
• Emphysematous bullae
• Recent oesophageal or lung surgery e.g. lobectomy
• Spinal instability
• Severe exacerbation of COPD / bronchospasm
• ARDS
• Raised intracranial pressure (ICP)
• Hypotension (Systolic <80)
• Cardiovascular instability / arrythmias
• Acute head injury
• Unexplained haemoptysis
• High respiratory rate
• Subcutaneous emphysema
• Recent meal
• Undrained pleural effusion
• Recent facial fractures, maxfax surgery or burns

Question 4

What is MI-E known as?

Answer 4

Cough Assist

Question 5

What does MI-E do?

Answer 5

Delivers a positive pressure on inspiration and a negative pressure on expiration.

Question 6

What is sputum retention typically due to with MI-E?

Answer 6

• Respiratory muscle weakness
• Reduced peak cough flow (<160L/min)
• Bulbar muscle involvement preventing ability to breath-stack