Videos

Supraglottic airway devices animated demonstration

How to size and insert a laryngeal mask airway.

Equipment needed

  • Personal protective equipment, including gloves

  • Laryngeal mask airway: an average-sized adult will require a size 4, but sizes needed range from 3 to 6 based roughly on weight

  • Syringe for inflating and deflating cuff (50 mL; ensure cuff inflates and deflates before insertion)

  • Lubrication

  • Bag-valve apparatus, including mask for pre-oxygenation

  • Suction

  • Oxygen

  • End-tidal CO2 monitor (if available)

  • Cotton tape to secure the tube.

Contraindications

  • Cannot open mouth

  • Complete upper airway obstruction (e.g., laryngospasm, foreign body).

Indications

  • Respiratory failure

  • Cardiac arrest

  • Anaesthesia.

Supraglottic airway (SGA) devices include laryngeal mask airways and second-generation SGA devices. Second-generation SGA devices have additional design features to reduce the risk of gastric aspiration. Many have a gel cuff instead of an inflatable cuff.

When an advanced airway is needed, an SGA or tracheal intubation (TI) can be used.[185]​ The choice of device depends on the experience and competence of the user. TI should be restricted to clinicians who can achieve a success rate of approximately 95% with two attempts of TI. One randomised controlled trial compared initial insertion of a second-generation SGA with initial TI in patients who had an out of hospital cardiac arrest in the UK. There was no difference in functional survival between the two groups.​[185]

SGA devices are tolerated at a level of consciousness between that required for an oropharyngeal airway and the lower level required for insertion of a tracheal tube.

Unlike tracheal intubation, an SGA device can generally be inserted without interrupting chest compressions.

The laryngeal seal achieved with an SGA may allow some gas leakage when inspiration coincides with chest compressions. Moderate gas leakage is acceptable (unless there is a significant risk of infection) but if inadequate ventilation results, compressions should be paused for ventilation using a compression-ventilation ratio of 30:2.[185]

An SGA does not protect the trachea reliably when compared with a tracheal tube. However, aspiration of materials into the lung is uncommon when using an SGA during a cardiac arrest. If aspiration occurs or if ventilation is inadequate, a tracheal tube may be required.

Complications

  • Aspiration of gastric contents

  • Local irritation

  • Upper airway trauma: pressure-induced lesions, nerve palsies

  • Mild sympathetic response

  • Complications associated with improper placement: obstruction, laryngospasm.

Aftercare

Continue to resuscitate the patient in keeping with life support guidelines, using ABCDE principles.