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Airway - Laryngeal mask airway

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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

Indications

Rescue airway device (failed rapid-sequence intubation, difficult bag-mask ventilation)

Cardiac arrest

Facial trauma

and

Deeply reduced level of consciousness (GCS 3, without gag reflex)

Contraindications (absolute in bold)

Limited mouth opening (<2cm)

High airway pressures

Alternatives

Bag-mask ventilation with oral or nasopharyngeal airway

Intubation

Informed consent

Medical emergency

Consent is not required

Potential complications

Failure to ventilate (incorrect placement, incorrect size, folding of cuff or epiglottis, distorted anatomy)

Laryngospasm (if airway reflexes intact)

Vomiting (if gag reflex intact)

Airway injury (with bleeding)

Aspiration

Pain

Procedural hygiene

Standard precautions

PPE: non-sterile gloves, surgical mask, protective eyewear or shield

Area

Resuscitation bay

Staff

Procedural clinician

Airway assistant

Equipment

LMA (sized by estimated patient weight, if uncertain use the larger LMA initially)

Water-soluble lubricant

Positioning

Neck flexion with atlanto-occipital extension (sniffing position), or

Neck in neutral position with spinal immobilisation (cervical injury suspected)

Head-tilt chin-lift or jaw thrust applied

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

Sequence (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

Start continuous waveform capnography and monitoring

Use ongoing bag-mask or pressure-controlled ventilation

Pass a 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

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

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 supraglottic airway devices (SADs) rather than laryngeal mask airways (LMAs). Current devices in emergency department use are not all LMAs. We have used the more common emergency department terminology of LMA.

Peer review

This guideline has been reviewed and approved by the following expert groups:

Emergency Care Institute

Please direct feedback for this procedure to ACI-ECIs@health.nsw.gov.au.

References

Australian Resuscitation Council and New Zealand Resuscitation Council. ANZCOR guideline 11.6 – equipment and techniques in adult advanced life support. Melbourne: Australian Resuscitation Council and New Zealand Resuscitation Council; 2016. 16pp. 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.

Dunn RJ, Borland M, O'Brien D (eds.). The emergency medicine manual. Online ed. Tennyson, SA: Venom Publishing; 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

User Guide: i-gel® single use supraglottic airway - adult and paediatric sizes. Issue 4. Wokingham UK: Intersurgical; 2020. Available from: https://www.intersurgical.com/content/files/80023/1103318462

Teleflex. The LMA Supreme Airway User Guide. Athlone, Ireland: Teleflex; 2014.

Park JH, Lee JS, Nam SB, et al. Standard versus rotation technique for insertion of supraglottic airway devices: systematic review and meta-analysis. Yonsei Med J. 2016 Jul;57(4):987-97. doi:10.3349/ymj.2016.57.4.987

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;45(2):98‐102. doi:10.5152/TJAR.2017.70298

Cook T, Howes B. Supraglottic airway devices: recent advances. Continuing Education in Anaesthesia Critical Care & Pain. 2011 Apr;11(22):56-61. doi:10.1093/bjaceaccp/mkq058

Aoyama K. The triple airway manoeuvre for insertion of the laryngeal mask airway in paralyzed patients. Canadian Journal of Anaesthesia. 1995 Nov;42(11):1010-16.

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