Supraglottic Airways and Alternative Devices

Supraglottic airway devices are airway tools that sit above the glottis and seal around the laryngeal inlet to allow ventilation without entering the trachea. Introduced with the laryngeal mask airway, they occupy a middle ground between face-mask ventilation and tracheal intubation and serve both as a primary airway and as a rescue device.

Definition

A supraglottic airway device is an airway adjunct positioned above the vocal cords that forms a seal around the laryngeal opening to permit spontaneous or controlled ventilation without tracheal intubation.

Scope

This topic covers the concept and generations of supraglottic airway devices, their role in routine anaesthesia and in airway rescue, and how they fit within difficult-airway strategies. It is a reference overview of the device class rather than guidance on selecting or inserting a device for a particular patient.

Core questions

• How does a supraglottic airway seal and maintain ventilation without intubation?
• When are these devices used as a primary airway versus a rescue device?
• What distinguishes first- from second-generation devices?

Key concepts

• Laryngeal mask airway
• Supraglottic seal
• First- and second-generation devices
• Gastric drainage channel
• Rescue ventilation
• Conduit for intubation
• Aspiration risk considerations

Mechanisms

A supraglottic airway is positioned in the hypopharynx so that an inflatable or anatomically shaped cuff seals around the laryngeal inlet, directing gas flow into the trachea while the device remains above the cords (Brain, 1983). Second-generation devices add features such as a separate channel for gastric drainage to reduce aspiration risk and improve the seal. Because they can be inserted rapidly and often blindly, these devices also function as a rescue route to restore oxygenation when mask ventilation or intubation fails, and some serve as a conduit for subsequent intubation (Frerk, 2015).

Clinical relevance

Supraglottic devices are used widely for suitable elective cases and hold a defined place in difficult-airway algorithms as a rescue step to maintain oxygenation; audit work highlights both their value and the importance of appropriate selection (Frerk, 2015; Cook, 2011). This entry describes the device class and is not individualised clinical advice.

Epidemiology

The NAP4 audit examined complications associated with all airway approaches, including supraglottic devices, informing recommendations on device choice and second-generation use (Cook, 2011).

Evidence & guidelines

Difficult-airway guidelines incorporate supraglottic airway insertion as a key rescue step when face-mask ventilation or intubation is failing, and emphasise considering second-generation devices; the device class originates with the laryngeal mask described by Brain (Frerk, 2015; Brain, 1983).

History

Archie Brain introduced the laryngeal mask airway in 1983 as a new concept bridging the gap between face mask and tracheal tube; the class subsequently expanded into multiple designs and second-generation devices with gastric access (Brain, 1983).

Debates

How should supraglottic airways be used when aspiration risk is a concern?

Their place relative to tracheal intubation in patients at higher aspiration risk is debated, motivating second-generation designs with gastric drainage and careful case selection.

Seminal works

• brain-1983
• frerk-2015

Frequently asked questions

What is a laryngeal mask airway?

It is the original supraglottic airway device, introduced by Brain in 1983, that seals around the laryngeal inlet to allow ventilation without passing a tube into the trachea (Brain, 1983).

How do supraglottic airways function in a difficult airway?

They can be inserted quickly to restore oxygenation when mask ventilation or intubation is failing and are a defined rescue step in difficult-airway guidelines (Frerk, 2015).