THIS SKILL STATION COVERS:
Bronchoscopic intubation via Supraglottic Airway Devices
The Aintree Intubating Catheter
When difficulty is encountered with Plan A, the main aim of Plan B is rescue oxygenation.
This station focuses on the effective use of Supraglottic Airway Devices (SADs) for this purpose and how they can be used, via bronchoscopic conversion, to secure a definitive airway.
Bronchoscopic intubation via a conduit (most commonly, a SAD) is a relatively low skill technique that can be very useful in difficult airway management, both anticipated and unanticipated.
In unanticipated difficult airway management, it forms part of Plan B of the DAS guidelines, and is a Green Zone conversion strategy in the Vortex approach, meaning that this strategy is only used if SAD insertion has been successful in achieving alveolar oxygenation.
The technique can also be used electively in the management of the known difficult airway.
SADs are foundational to Plan B as they provide a stable conduit for bronchoscopic intubation. The evolution of these devices has significantly enhanced their utility for this specific application. Historically, first-generation devices such as the classic LMA™ were successfully used for this purpose. However, contemporary practice increasingly favours the use of second-generation SADs.
Second-generation SADs incorporate several key design improvements that make them superior for use as intubation conduits :
- Enhanced airway seal: A better airway seal improves the effectiveness of ventilation, which is crucial for maintaining oxygenation as part of the rescue strategy.
- Gastric channel: These devices include a dedicated channel to vent regurgitated gastric contents, thereby reducing the risk of pulmonary aspiration.
- Design for bronchoscopic conversion: The devices feature a wider and shorter airway channel and a larger, open bowl that provides an unobstructed path for tube delivery.
Examples of widely used second-generation devices include the Intersurgical i-gel™, the Ambu AuraGain™, and the Proseal LMA™. For a comprehensive airway trolley, it is recommended to stock both first- and second-generation devices, as the latter may be too bulky for patients with poor mouth opening.
i-gel™
i-gel™
- Gastric channel
- Short airway channel
- Wide bowl
- Gel-filled cuff
AuraGain™
AuraGain™
- Gastric channel
- Short airway channel
- Wide bowl
- Air-filled cuff
Proseal LMA™
Proseal LMA™
- Gastric channel
- Short airway channel
- Air-filled cuff
- Best seal pressure
Classic LMA™
Classic LMA™
- Long airway channel
- No gastric channel
- Elevator bars
- Low profile
Blind techniques carry a significant risk of airway trauma, oesophageal intubation, and a lower success rate, particularly when multiple attempts are required. Using bronchoscope is now a well-established and recommended technique.
Once a tracheal tube has been placed, there is no urgent need to remove the SAD. It is very unlikely to cause harm unless intubation is to be prolonged, in which case an airway exchange catheter technique should be used for SAD removal.
The Aintree Intubating Catheter (AIC) is a specialised adjunct specifically designed for Plan B techniques. Its addition offers two primary advantages :
- SAD Removal: The AIC allows for the removal of the SAD at the time of tracheal tube insertion, a manoeuvre that is otherwise complicated and risks loss of the airway.
- Continuous Oxygenation: The catheter enables the provision of oxygen at each stage of the conversion process.
Aintree Intubating Catheter™
Aintree Intubating Catheter™
- 56 cm long – fits over standard-length bronchoscope (60 cm)
- Internal diameter 4.7 mm – for use with slim bronchoscope
- Outer diameter 6.5 mm – use minimum size 7.0 ETT
To prevent the “loss” of the AIC or its accidental removal from the airway while the SAD is being withdrawn, a two-person technique is recommended.
Additionally, removing the connector from the endotracheal tube (ETT) can provide an extra 1.5 cm of grip on the AIC, and an Airway Exchange Catheter (AEC) can be inserted down the middle of the AIC to effectively lengthen it, a manoeuvre often used to further secure the airway.
Plan B techniques are useful for both anticipated and unanticipated difficult airways. The techniques capitalise on the design improvements of second-generation SADs, which provide a stable conduit for tracheal intubation.
A key component of this approach is the Aintree Intubating Catheter, which addresses the crucial logistical challenges of maintaining oxygenation and facilitates a safe, controlled exchange of airway devices.
It is important to note that Plan B techniques should only be performed in the Green Zone.