Cardiothoracics

Question 1

How can the risks associated with lung resection be quantified preoperatively?

Answer 1

• ASA class
• respiratory mechanics; PPO FEV1
  • Low risk >40%
  • Mod risk 30-40%
  • High risk <30%
• Parenchymal function; PPO DLCO
  • increased risk if<40%
• cardiorespiratory interaction; VO2 max
  • Low risk >20ml/kg/min
  • Mod risk 15-20ml/kg/min
  • High risk <15ml/kg/min
  -V/Q scan to modify PPO measures

Question 2

What are the indications for one lung ventilation?

Answer 2

Absolute indications;
Lung protection to prevent contamination
Control of ventilation (bronchopleural fistula, pneumothorax, bronchial disruption, surgery on main bronchus)
Unilateral lung lavage

Relative indications;
Surgical access i.e. thoracic aorta, pneumonectomy/low back to me, VATS surgery, mediastinum/oesophagus surgery

Question 3

How do you manage the development of hypoxaemia during one lung ventilation?

Answer 3

Increase FiO2
Check positioning of double lumen tube or bronchial blocker
Rule out pneumothorax of dependent lung
Improve ventilation parameters of dependent lung; PEEP, I:E
Insufflate oxygen via catheter into non-dependent lung
CPAP of non-dependent long
Intermittent ventilation of both lungs
Abandon operation
Clamp pulmonary artery of non-dependent lung