Airway – Laryngeal mask

Procedure, instructions and discussion

Laryngeal mask airway (LMA) for airway compromise and deeply reduced level of consciousness or arrest

Covering the iGel and Supreme LMA insertion techniques

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Laryngeal mask Airway – iGel

Laryngeal mask Airway – Supreme

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Instructions

Indications

• Airway compromise

and

• Deeply reduced level of consciousness or arrest

Contraindications (ABSOLUTE/relative)

• LIMITED MOUTH OPENING (<2CM)
• High airway pressures

Alternatives

• Oropharyngeal airway (OPA)
• Nasopharyngeal airway (NPA)
• Bag-Valve-Mask (BVM )Ventilation
• Intubation

Informed consent

NOT REQUIRED

• Consent is not required.
• This is an emergency procedure to save a life

Potential complications

• Failure of placement (incorrect size, folding cuff/epiglottis)
• Failure of ventilation (poor seal, incorrect size)
• Laryngospasm (if airway reflexes intact)
• Vomiting (if gag reflex intact)
• Airway injury (with bleeding)
• Aspiration
• Pain

Infection control

• Standard precautions
• PPE: non-sterile gloves, N95 mask, protective eyewear or shield

Area

• Resuscitation bay

Staff

• Procedural clinician
• Airway assistant

Equipment

• LMA (sized by estimated patient weight)
• Water-soluble lubricant

Positioning

• Neck flexion with atlanto-occipital extension (head tilt, chin lift into sniffing position

OR

• Neck in neutral position with spinal immobilisation (jaw thrust applied – cervical injury suspected)

In adults the sniffing position is achieved by elevating head approximately 10cm while tilting the head posteriorly. This achieves horizontal alignment of the sternum and external auditory meatus. Small children do not require head lift and infants will require slight elevation of the shoulders due to a relatively large occiput.

Medication

• Consider sedation and paralysis if not deeply unconscious (GCS 3, without gag reflex)

Sequence

Insertion

• Completely deflate cuff (if present), smoothing leading edge
• Place lubricant on the posterior and lateral aspects of the LMA
• Grasp LMA firmly on the integral bite block
• Position the device with cuff facing towards the chin of the patient
• Place your other hand on the patient’s occiput to stabilise head during insertion
• Press chin inferiorly opening mouth and insert the LMA tip into mouth towards the hard palate
• Glide the device downwards and backwards along the hard palate with continuous pressure
• Notice a give just before the end point of insertion (passage through the faucial pillars)
• Cease pressure when definitive resistance is met (bite block should now rest on the patient’s incisors)
• Hold LMA in position and inflate the cuff (if present) with half the maximum volume of the cuff
• Tape from maxilla to maxilla and across fixation tab or around the LMA if no tab present Attach a bag and ventilate assessing chest rise, breath sounds and waveform capnography

Troubleshooting if poor or noisy ventilation

• Move LMA up and down 2-4cm (to correct folding of LMA cuff or epiglottis)
• Reinsert with triple manoeuvre (mouth opening, head extension and jaw thrust)
• Reinsert with cuff facing right laterally, applying ‘deep rotation’ 90 degrees anticlockwise into pharynx
• Adjust patient (head-tilt chin-lift, jaw thrust, chin to chest, anterior neck pressure)
• Insert air into LMA cuff (be aware overfilling may worsen seal)
• Change size of LMA (larger if air leak on ventilation, smaller if unable to position correctly)
• Consider sedation and paralysis (laryngospasm may occur if not deeply unconscious)
• If unresolved, consider bag-mask ventilation, intubation or surgical airway

Post-procedure care

DOCUMENT PROCEDURE

• Continuous waveform capnography
• Continuous monitoring
• Bag-mask or pressure-controlled ventilation
• Lubricated orogastric tube via the LMA’s gastric drainage tube
• Consider sedation and paralysis
• Prepare for intubation (seeking senior help if required)
• Document after securing definitive airway (completion, complications)

Tips

• If uncertain of patient weight use a larger LMA initially.
• LMA ventilation in facial trauma will reduce aspiration of blood compared to bag-mask ventilation
• Sedation and paralysis will usually be required to tolerate an LMA
• Current generation LMAs do not require placing fingers in the mouth on insertion

Discussion

LMA’s are excellent rescue airway devices suitable for use during failed rapid-sequence intubation when bag-mask ventilation is difficult. They are also particularly useful for oxygenating patients with upper airway bleeding where bag mask ventilation would encourage the passage of blood into the lower airway. 

The method of insertion is similar for all types of LMA and is applicable across devices. We have based our description around the i-gel (non-cuffed) and the Supreme (cuffed) LMA

For second generation devices (e.g. LMA Supreme, i-gel) with a reinforced airway tube, digital insertion is no longer required. We recommend primary insertion as described by the LMA manufacturer with a rotational method used if this fails.

The correct terminology for this section should be a supraglottic airway device (SAD) rather than laryngeal mask airway (LMA). Current devices in emergency department use are not all LMAs. We have used the more common emergency department terminology of LMA.

References

• Cadogan M. Archie Brain and the birth of the LMA. LITFL
• Nickson C. Laryngeal Mask Airway (LMA). LITFL
• User Guide: i-gel® single use supraglottic airway – adult and paediatric sizes. Issue 4. Wokingham UK: Intersurgical; 2020.
• Teleflex. The LMA Supreme Airway User Guide. Athlone, Ireland: Teleflex; 2014.
• Park JH, Lee JS, Nam SB, Ju JW, Kim MS. Standard versus Rotation Technique for Insertion of Supraglottic Airway Devices: Systematic Review and Meta-Analysis. Yonsei Med J. 2016 Jul;57(4):987-97.
• Dhulkhed PV, Khyadi SV, Jamale PB, Dhulkhed VK. A Prospective Randomised Clinical Trial for the Comparison of Two Techniques for the Insertion of Proseal Laryngeal Mask Airway in Adults-Index Finger Insertion Technique versus 90° Rotation Technique. Turk J Anaesthesiol Reanim. 2017 Apr;45(2):98-102.
• Cook T, Howes B. Supraglottic airway devices: recent advances. Continuing Education in Anaesthesia Critical Care & Pain. 2011 Apr;11(22):56-61.
• Aoyama K, Takenaka I, Sata T, Shigematsu A. The triple airway manoeuvre for insertion of the laryngeal mask airway in paralyzed patients. Can J Anaesth. 1995 Nov;42(11):1010-6
• Australian Resuscitation Council and New Zealand Resuscitation Council. ANZCOR guideline 4 – airway. Melbourne: Australian Resuscitation Council and New Zealand Resuscitation Council; 2016. 7pp. Available from https://resus.org.au/guidelines/
• Roberts JR, Custalow CB, Thomsen TW. Roberts and Hedges’ clinical procedures in emergency medicine and acute care. 7th ed. Philadelphia, PA: Elsevier; 2019.
• Doyle DJ. Supraglottic devices (including laryngeal mask airways) for airway management for anesthesia in adults. In: UpToDate. Waltham (MA): UpToDate. 2019 May 16: Retrieved May 2020. Available from: https://www.uptodate.com/contents/supraglottic-devices-including-laryngeal-mask-airways-for-airway-management-for-anesthesia-in-adults
• Bosson N. Laryngeal mask airways. Medscape. 2018 Dec 28. WebMD LLC. Retrieved May 2020. Available from: https://emedicine.medscape.com/article/82527-overview

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