They are particularly helpful during “can’t intubate, can’t ventilate” scenarios as they are easy to insert for airway rescues. They can be blindly placed and connected to a ventilator for up to 6 hours, allowing healthcare professionals to stabilize the patient until they can establish a more definitive and secure airway.
Let’s explore the indications for inserting a laryngeal mask and its potential risks.
What Is a Laryngeal Mask Airway?
A laryngeal mask airway (LMA) refers to a reusable or disposable supraglottic airway device that has been used since 1988. It was developed by anesthesiologist and inventor Dr. Archie Brain.
Shaped like a large endotracheal tube (ETT) on the proximal end, an LMA helps keep the airway open by connecting the distal end to an elliptical mask. It sits on the patient’s hypopharynx and enables the relative isolation of the trachea.
The laryngeal mask airway was initially designed as elective ventilation in operating rooms. But it has since made its way into emergency settings and out-of-hospital care. It is often used for managing difficult airways as an alternative to bag-valve-mask ventilation since it frees the hands of the healthcare provider while providing less gastric distention. This reduces the risk of aspiration and is particularly useful for patients who have not fasted before being ventilated.
What are the Indications for Inserting a Laryngeal Mask?
Laryngeal mask airways can be used to temporarily maintain an open airway when anesthesia is administered. They are also useful for life-threatening situations involving difficult or failed airways.
It is crucial for healthcare providers to know when to use a laryngeal mask airway. It’s often employed in the following situations:
Elective Ventilation
An alternative to mask anesthesia in operation rooms, a laryngeal mask airway is used during short procedures when endotracheal intubation is not required.
Difficult Airway Management
A laryngeal mask airway is used as a rescue device in situations involving a difficult airway where the patient can only be ventilated, not intubated.It offers an effective, easier alternative to bag-valve-mask ventilation as it may decrease the risk of aspiration while being easier to maintain over time.LMA can also be attempted simultaneously with the preparation for a cricothyroidotomy for patients who cannot be intubated or ventilated.
Cardiac Arrest
LMA is an appropriate alternative for airway management among patients experiencing cardiac arrest as per the American Heart Association guidelines.This is especially true for prehospital settings where first responders may have less experience and lower success rates with intubation.
Conduit for Intubation
When direct laryngoscopy is unsuccessful, An intubating LMA can act as a conduit for intubation as an ETT can be placed through it directly or may be assisted by a fiberoptic scope or bougie.
Prehospital Airway Management
A laryngeal mask intubation can be useful in general prehospital settings for difficult airway management until it is possible to establish a definitive airway.If endotracheal intubation is deemed unviable with positioning or prolonged extrication, an LMA offers an effective and reliable alternative.
Pediatric Use
Pediatric patients can also benefit from laryngeal mask airways as the first-attempt success rate in children is between 67% and 92%. The protocol for children is to deflate the mask with a syringe and to use lubricant jelly to make insertion more comfortable for the patient.
Alternative to Bag-Valve-Mask Ventilation
Some patients may have severe facial deformities, a thick beard, or other factors that may interfere with the seal of the face mask in bag-valve-mask ventilation. Laryngeal mask airway insertion can ensure reliable airway management in such situations by acting as an alternative to bag-valve-mask ventilation.
What are the Contraindications for Laryngeal Mask Airway?
Laryngeal mask airways are typically associated with few complications. They are reliable, effective, efficient, and simple while offering a high success rate.
However, it still has certain side effects such as:
- Nausea
- Vomiting
- Aspiration
- Coughing
- Transient unilateral lingual nerve injury
- Laryngospasm
- Local irritation
- Upper airway trauma
- Pulmonary edema
- Bronchoconstriction
- Mild sympathetic response
- Upper airway trauma such as nerve palsies or pressure-induced lesions
Absolute contraindications of this technique include patients who cannot open their mouths, patients who are conscious as the gag reflex may be stimulated, and patients with a complete obstruction of the upper airways.
What Is the Equipment Used in Laryngeal Mask Airway Insertion?
The equipment used for laryngeal mask airway insertion includes:
- Laryngeal mask
- Water-soluble lubricant
- Appropriate syringe for cuff inflation
- Source of oxygen
- Bag-valve mask
- Yankauer suction device
- End-tidal carbon dioxide (ET CO2) detector
Intubation equipment and cricothyroidotomy kits must also be kept close by to establish a more definitive airway depending on the situation.
Important Tips for Laryngeal Mask Insertion
To effectively insert a laryngeal mask, here are some things to keep in mind:
- Keep the ventilation pressure low to prevent gastric insufflation.
- Adjust the cuff pressure if the seal is inadequate.
- The sniffing position is the optimal patient position during insertion.
- To make ventilation easier, you can adjust the patient’s position during bag-valve ventilation.
It is also important to keep other airway management devices at hand, particularly if spinal injury is a potential concern.
Final Thoughts
Knowing the indications and contraindications for inserting a laryngeal mask is crucial, particularly if you’re a first responder who encounters several emergency situations. Over the years, the procedure has proven to be a reliable and life-saving airway management technique for healthcare professionals.
If you’re looking to enhance your knowledge regarding LMA, Hospital Procedures Consultants offers a Laryngeal Mask Airway Course and other learning resources that can help increase your familiarity with the techniques involved.
Resources:
Timmermann, A. Bergner, U. Russo, S. Laryngeal mask airway indications: new frontiers for second-generation supraglottic airways. Curr Opin Anaesthesiol. 2015 ;28:717-26.
Jannu, A. Shekar, A. Balakrishna, R. Sudarshan, H. Veena, G. Bhuvaneshwari, S. Advantages, Disadvantages, Indications, Contraindications and Surgical Technique of Laryngeal Airway Mask. Arch Craniofac Surg. 2017 Dec;18(4):223-229. doi: 10.7181/acfs.2017.18.4.223. Epub 2017 Dec 23.
O´Neill B. Templeton, J. Caramico, L. Schreiner, M. The laryngeal mask airway in pediatric patients: factors affecting ease of use during insertion and emergence. Anesth Analg. 1994 Apr;78(4):659-62.
V. Leslie. Simon, L. Torp, D. Laryngeal Mask Airway. Continuing Education Activity. 2023, 07.