What are the advantages and disadvantages of jet ventilation versus conventional ventilation during rigid bronchoscopy?

Advantages and Disadvantages of Jet and Conventional Ventilation During Rigid Bronchoscopy

For patients undergoing rigid bronchoscopy, both jet ventilation and controlled/spontaneous assisted ventilation are effective options with no significant difference in therapeutic success rates, complications, or mortality. 1

Jet Ventilation

Advantages:

• Provides unobstructed access to the airway as the proximal end of the bronchoscope remains open, allowing easier passage of instruments 1
• Associated with less significant hypercapnia compared to controlled ventilation 1
• Effective oxygenation and carbon dioxide removal even in cases of tracheal stenosis 2
• Can be delivered either manually (Sander's technique) at 10-14 breaths per minute or using high-frequency automated machines at 60-300 breaths per minute 1
• Superimposed high frequency jet ventilation (combining normal and high frequency) improves oxygenation by increasing lung volume and carbon dioxide removal 2

Disadvantages:

• Creates an open system that releases aerosols into the room, making it a high-risk procedure, especially during infectious disease outbreaks 1
• Requires high-pressure oxygen (typically 50 psi) which increases risk of barotrauma if ventilator settings aren't properly adjusted 2
• May be more difficult to monitor ventilation parameters compared to conventional methods 3
• Requires specialized equipment and expertise 2

Conventional Ventilation (Controlled/Spontaneous Assisted)

Advantages:

• Creates a closed circuit system that reduces aerosol dispersion, making it safer during infectious disease outbreaks 1
• Allows for better monitoring of ventilation parameters 1
• Provides more predictable minute ventilation 1
• Can be more familiar to anesthesiologists who routinely use conventional ventilation techniques 1

Disadvantages:

• Associated with more significant hypercapnia compared to jet ventilation 1
• Requires sealing the rigid bronchoscope, which may limit access for instruments 1
• May require additional adaptations like rubber caps on ports or plastic coverings that can make instrument handling more challenging 1
• May require higher oxygen flow rates compared to some alternative ventilation methods 4

Clinical Considerations

Efficacy Comparison:

• According to the AQuIRE registry, there was no significant difference between controlled/spontaneous assisted ventilation (92.9% success) and jet ventilation (96.1% success) in therapeutic success rates 1
• Both methods showed similar improvements in dyspnea, quality of life, complications, and complication-related mortality 1

Patient Selection Factors:

• For patients with infectious diseases (e.g., COVID-19), controlled ventilation is preferred to minimize aerosol dispersion 1
• For procedures requiring frequent instrument passage, jet ventilation may provide better working conditions 2
• For patients with severe tracheal stenosis, high-frequency jet ventilation may be particularly effective 2, 5

Procedural Considerations:

• Regardless of ventilation technique, general anesthesia/deep sedation is recommended over moderate sedation for therapeutic bronchoscopy 1
• Continuous multi-modal physiological monitoring is mandatory throughout the procedure 6
• A multidisciplinary approach involving pulmonologists and anesthesiologists is essential for optimal outcomes 1

Common Pitfalls and How to Avoid Them:

• Risk of barotrauma with jet ventilation: Adjust pause pressure and peak inspiratory pressure appropriately 2
• Inadequate ventilation monitoring: Consider intermittent capnography by temporarily reducing jet frequency to obtain end-tidal CO2 measurements 3
• Air leaks: Use rubber caps on ports of rigid scope and plastic coverings or gauze to reduce leakage 1
• Instrument handling difficulties with sealed systems: Prepare alternative instruments or techniques if conventional ventilation is used 1

The American College of Chest Physicians clinical practice guideline suggests that the choice between jet ventilation and controlled/spontaneous assisted ventilation should be made based on a multidisciplinary partnership with the anesthesiology team and the best use of available equipment to optimize patient outcomes 1.