Supraglottic airway devices

What it is

A supraglottic airway device sits above the glottis and seals around the laryngeal inlet, so a patient can breathe or be ventilated through it without passing anything through the vocal cords. The best-known type is the laryngeal mask airway: a tube ending in an oval cuff that lies in the hypopharynx, with its tip in the upper oesophageal sphincter and its bowl facing the laryngeal opening. Some cuffs are inflated, others are made of a soft gel that moulds to the anatomy. Second-generation devices add a gastric drainage channel and seal at higher airway pressures, which lowers the risk of aspiration; some also allow intubation through them. Insertion is blind, quick and easier to learn than intubation, so these devices are used in cardiac arrest, as a rescue airway when intubation or mask ventilation fails (in the difficult airway algorithms), and for planned anaesthesia in fasted patients. They do not fully protect the lungs from aspiration and leak when high ventilation pressures are needed. Size is chosen by the patient's weight from the device's own chart.

Indications

• Cardiac arrest, especially when intubation skills are not immediately available; compressions may continue if there is no major leak.
• Rescue airway in the difficult airway algorithms after failed intubation or failed mask ventilation.
• Planned general anaesthesia for short procedures in fasted patients at low aspiration risk.
• A conduit for intubation, through devices designed for it, often with a fibre-optic scope.
• Prehospital airway management by trained staff.

Contraindications and precautions

• High aspiration risk: full stomach, bowel obstruction, late pregnancy or active vomiting (relative, not in an arrest).
• Intact gag reflex or lightly sedated patient: can cause coughing, vomiting and laryngospasm.
• Limited mouth opening, or pathology of the pharynx or larynx (tumour, abscess, trauma, swelling).
• Obstruction at or below the glottis, which the device cannot bypass.
• Low lung compliance or high airway resistance (severe bronchospasm, obesity): the seal leaks at the pressures needed.

Equipment

• Supraglottic devices in the sizes chosen from the manufacturer's weight chart.
• Syringe for cuff inflation (inflatable types) and, ideally, a cuff pressure gauge.
• Water-based lubricant for the back of the cuff.
• Bag-valve system with oxygen, suction, and a gastric tube for the drainage channel.
• Waveform capnography, stethoscope, tape or tie and a bite block.

Step by step (and why)

1. Pre-oxygenate with a bag and mask and pick the size from the weight chart — a well-oxygenated patient tolerates a pause.
2. Check the cuff (deflate it fully if inflatable) and lubricate its back only — lubricant on the front can be aspirated or block it.
3. Place the head in the sniffing position if the neck allows — this opens the angle between mouth and pharynx.
4. Open the mouth and slide the device along the hard palate, bowl facing the tongue — following the palate stops it folding.
5. Advance in one smooth movement into the hypopharynx until resistance is felt — the tip now sits in the upper oesophagus.
6. Inflate the cuff as the manufacturer advises, without holding the tube — it usually rises a little as it seats.
7. Connect the bag and ventilate; confirm chest rise, breath sounds and a capnography trace — this proves gas reaches the lungs.
8. Secure the device with a bite block and pass a gastric tube through the drainage channel if there is one — this vents the stomach.
9. Reassess after any move and keep cuff pressures low — a shifted or overinflated device leaks or injures the mucosa.

Complications

• Regurgitation and pulmonary aspiration of gastric contents.
• Malposition, such as the epiglottis folded down over the glottis, causing leak or obstruction.
• Laryngospasm, coughing and bronchospasm, especially in light planes of sedation.
• Sore throat, mucosal injury and, rarely, lingual, hypoglossal or recurrent laryngeal nerve injury from cuff pressure.
• Gastric insufflation and inadequate ventilation when high pressures are needed.

Next step

• If ventilation is poor, reposition or try another size; if it still fails, call the senior airway clinician at once.
• In a can't intubate, can't oxygenate situation, the next step is an emergency front-of-neck airway by the most skilled person.
• Plan a definitive airway (intubation, possibly through the device) when the patient needs prolonged ventilation or aspiration protection.
• Keep monitoring saturation and capnography continuously; a lost trace means a displaced or blocked airway until proven otherwise.
• Before removal, suction the mouth and remove the device when airway reflexes return, or as planned by the anaesthetist.

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Elsewhere in DurgiPedia

• Basic life support from the nursing side
• Airway resistance
• Lung and chest wall compliance

Connections

← All clinical skills

Educational content; it does not replace supervised hands-on training, your institution's protocols or a prescriber's order. A procedure is learnt with a teacher and done only once you are trained to do it.

Sources: Laryngeal Mask Airway (StatPearls (NCBI Bookshelf), 2026); Airway Management (StatPearls (NCBI Bookshelf), 2025).

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