Learning objectives

• Describe the indications & contraindications of one-lung anesthesia
• Perform one-lung anesthesia
• Manage hypoxia during one-lung anesthesia

Background

• One-lung anesthesia defines the process of complete functional separation of the lungs
• Involves ventilating one lung and collapsing the other
• Facilitates certain types of surgery, but causes significant physiological disadvantages

Indications

• Protective isolation
  • Prevent contamination or spillage of infectious material (pus or secretions) from the contralateral lung
  • Prevent massive hemorrhage
• Control the distribution of ventilation between the two lungs in the presence of:
  • Bronchopleural fistula
  • Giant unilateral cyst/bulla
  • Surgical opening of major airway
  • Tracheobronchial tree disruption
• Unilateral bronchopulmonary lavage (e.g., for alveolar proteinosis)
• Video-assisted thoracoscopic surgery 
• Facilitate surgical exposure (e.g., pneumonectomy, lobectomy, thoracoscopy, esophageal surgery, thoracic aneurysm, thoracic spinal surgery)

Contraindications

• Patient dependent on bilateral ventilation
• Intraluminal airway masses 
• Hemodynamic instability
• Severe hypoxia
• Severe COPD
• Severe pulmonary hypertension 
• Known or suspected difficult intubation

Lung separation

• Double lumen tube: Allows rapid transition between one-lung ventilation and two-lung ventilation, most commonly used technique
• Bronchial blockers: Do not facilitate ventilation or suction distal to the blocker
• Uncut tracheal tube: Can be advanced into the relevant main bronchus, generally only used in emergency situations
• Papworth BiVent tube: New double lumen tube designed to facilitate rapid and reliable lung isolation using a bronchus blocker without endoscopic guidance

Technique (double lumen tube)

Complications

• Hypoxemia is one of the most important complications encountered during one-lung anesthesia
• Management of hypoxemia:
  • Increase inspired oxygen to 100%
  • Check the position of the tube with a fiberoptic bronchoscope
  • Ensure adequate blood pressure and cardiac output
  • Positive end-expiratory pressure 5-10 cmH2O to the dependent lung to decrease atelectasis and increase functional residual capacity
  • Continuous positive airway pressure 5-10 cmH2O with 100% oxygen to the non-ventilated lung
  • If hypoxemia is severe and does not resolve with the aforementioned steps: Abandon one-lung ventilation and intermittently ventilate the collapsed lung after warning the surgeon
  • Early clamping of the appropriate pulmonary artery to stop the shunt

Suggested reading

• Mehrotra M, Jain A. Single Lung Ventilation. [Updated 2022 Jul 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538314/
• Ashok V, Francis J. A practical approach to adult one-lung ventilation. BJA Educ. 2018;18(3):69-74.
• Pollard BJ, Kitchen, G. Handbook of Clinical Anaesthesia. Fourth Edition. CRC Press. 2018. 978-1-4987-6289-2.