What is an LMA?
The LMA (laryngeal mask airway) is an advanced airway alternative to endotracheal tube (ET) intubation that provides comparable ventilation. It is acceptable for healthcare providers to use the LMA as an alternative to an ET tube for airway management in cardiac arrest. However, there are certain situations where an LMA would be contraindicated.
Please note that only experienced healthcare providers should perform LMA insertion.
LMA and Advanced Airways
The selection of an advanced airway device is dependent on the healthcare provider’s training, the scope of practice, and availability. Some of the more common types of advanced airways include:
- LMA (laryngeal mask airway)
- Laryngeal tube
- Esophageal-tracheal tube
- ET tube
It bears mentioning that a small percentage of patients cannot be ventilated with an LMA, as patients with a gag reflex may require another method. Therefore, healthcare providers who use an LMA device should have an alternative airway management strategy in place, such as a bag-mask device.
However, as you see below, this isn’t the only scenario in which an LMA alternative should be considered, but it may be the most common.
LMA as part of the Primary Assessment
When conducting a primary assessment, healthcare providers should ask themselves the following questions pertaining to airway management:
- Is the airway patent?
- Is an advanced airway indicated?
- Have you confirmed the proper placement of an advanced airway device?
- Have you properly secured the tube?
- Are you periodically reconfirming the placement of the advanced airway?
The first step for healthcare providers is to maintain airway patency in unconscious patients by use of the head tilt-chin lift or basic airways like an oropharyngeal airway (OPA), or nasopharyngeal airway (NPA).
Should those techniques prove ineffective, healthcare providers should then consider using an advanced airway management device, such as an LMA, laryngeal tube, esophageal-tracheal tube, or endotracheal tube.
Healthcare providers should also weigh the benefit of advanced airway placement against the negative effects of interrupting chest compressions, which are vital in any resuscitation scenario.
However, it’s important to remember that advanced airway devices such as LMAs, laryngeal tubes, or esophageal-tracheal tubes can be inserted without interrupting chest compressions. Also note that LMAs are only temporary and should be removed or replaced after several hours by a more definitive airway, like an endotracheal tube.
If bag-mask ventilation is adequate, healthcare providers may want to hold off on inserting an advanced airway. However, if the patient does not respond to initial CPR and defibrillation efforts, an advanced airway, like an LMA, may be necessary.
The use of an LMA is indicated in the following scenarios:
- Apnea, severe respiratory failure, or impending respiratory arrest in which endotracheal intubation cannot be accomplished
- Certain elective anesthesia cases
LMAs are useful in situations where bag valve mask ventilation is difficult, such as with patients who have a severe facial deformity, a thick beard, or any other factors that could interfere with the bag valve mask seal.
LMA contraindications range from absolute (never use) to relative (possibly use).
Never use an LMA
Healthcare providers should not use an LMA if:
- There is a legal contraindication (do-not-resuscitate order or a specific advanced directive) is in force
- The maximum mouth opening of the patient between incisors is less than 2cm
- There is an impassable upper airway obstruction
Consider an Alternative to an LMA
Healthcare providers should consider an LMA alternative if:
- The patient is conscious or has a gag reflex; patients should be unconscious or receive a sedative or a paralytic agent before LMA insertion
- There is an increased risk of regurgitation – prolonged prior bag valve mask ventilation, obesity, pregnancy, upper gastrointestinal issues, etc.
- There is a need for high-pressure ventilation
Be aware that LMA complications do exist and these include:
- Vomiting and aspiration
- Tongue edema due to prolonged placement or balloon over-inflation
- Dental or oropharyngeal soft tissue trauma during insertion