Effects of surgery

Question 1

Things that affect airway clearance post surgery?

Answer 1

→ Inhaled anaesthetic (during surgery)
→ Dehydration (during and after surgery)
→ Pain (after surgery)

All lead to impaired airway clearance which increases the risk of retained secretions.

Question 2

Effect of inhaled anaesthetic on airway clearance?

Answer 2

• irritates bronchial mucosa
• increases secretions
• inhibits ciliary movement

Question 3

Effect of dehydration on airway clearance?

Answer 3

• immobilises the cilia
• results in thick, sticky secretions which are difficult to expectorate

Question 4

Effect of pain after surgery on airway clearance?

Answer 4

Inhibits effective cough

Question 5

Things that affect lung volume after surgery?

Answer 5

→ Inhaled anaesthetic
→ Pain
→ Recumbency (decreases FRC)
→ Immobility and supine position (reduces FRC)

All of these may lead to atelectasis (collapse)

Question 6

Effect of inhaled anaesthetic on lung volume after surgery?

Answer 6

• reduces functional residual capacity
• reduces lung compliance (the ability of the lungs to stretch and expand) = reduced lung volume

Question 7

Effect of pain on lung volume and surgery?

Answer 7

• reduced residual lung capacity (volume in lungs after normal, passive exhalation)
• inhibits breathing and moving

Question 8

What factors increase closing capacity?

Answer 8

• age
• smoking history
• lung pathology

Question 9

What is closing volume?

Answer 9

The lung volume at which airway closure begins to occur

Question 10

Key points on effects of surgery?

Answer 10

• general anaesthetic + surgery increase mucus production and reduce lung volume
• patients at risk of chest infection and hypoxaemia
• factors about the operation can increase this risk
• factors about the patient can increase this risk
• preoperative examination + assessment can help to identify at-risk patients.