Laryngeal Mask Airway (LMA) in Pediatrics
Introduction
The Laryngeal Mask Airway (LMA) is a supraglottic airway device that provides a secure airway for breathing and ventilation without the need for endotracheal intubation. It sits above the larynx and creates a seal around the laryngeal inlet, making it an essential tool in pediatric anesthesia and emergency airway management.
This device has revolutionized airway management in children since its introduction, offering a middle ground between face mask ventilation and endotracheal intubation. It is particularly valuable when intubation is difficult or when a less invasive airway is preferred.
Purpose and Clinical Applications
The LMA serves multiple purposes in pediatric care:
- Routine Anesthesia: Used during elective surgical procedures requiring general anesthesia in children
- Emergency Airway Management: Provides rapid airway access when endotracheal intubation fails or is not immediately possible
- Difficult Airway Situations: Alternative when standard intubation is challenging due to anatomical variations
- Resuscitation: Used during cardiopulmonary resuscitation (CPR) when skilled personnel are available
- Transport: Maintains airway during patient transfers between facilities or departments
Common Settings Where LMA is Used
- Operating rooms for pediatric surgeries
- Emergency departments
- Intensive care units
- Ambulance and air transport services
- Remote locations requiring airway management
Types of Laryngeal Mask Airways
Several types of LMAs are available for pediatric use, each designed for specific applications:
| Type | Description | Best Use |
|---|---|---|
| Classic LMA | Original reusable design with inflatable cuff and standard airway tube | Routine anesthesia, short procedures |
| LMA Unique | Single-use disposable version of the classic LMA | All settings where infection control is priority |
| LMA ProSeal | Features a drainage tube for gastric access and improved seal | Longer procedures, patients at risk of aspiration |
| LMA Supreme | Single-use with gastric access port and ergonomic design | Routine and emergency use with aspiration risk |
| LMA Fastrach | Designed to facilitate endotracheal intubation through the device | Difficult airway scenarios requiring intubation |
| i-gel | Cuffless design with gel-like material that molds to anatomy | Emergency situations, quick insertion needed |
Pediatric Size Selection
| Size | Patient Weight | Age Range |
|---|---|---|
| 1 | Up to 5 kg | Neonates and small infants |
| 1.5 | 5 to 10 kg | Infants |
| 2 | 10 to 20 kg | Infants and small children |
| 2.5 | 20 to 30 kg | Children |
| 3 | 30 kg and above | Larger children and adolescents |
How to Use: Step-by-Step Guide
Pre-Insertion Preparation
- Check the device for damage, ensure the cuff inflates and deflates properly without leaks
- Select appropriate size based on patient weight and age
- Deflate the cuff completely and apply water-based lubricant to the posterior surface
- Position the child supine with head in sniffing position (slight neck flexion, head extension)
- Ensure adequate anesthesia or sedation and muscle relaxation if required
- Pre-oxygenate the patient adequately
Insertion Technique
- Hold the LMA like a pen with the index finger at the junction of the cuff and tube
- Press the deflated cuff tip against the hard palate with the aperture facing forward
- Advance the device along the hard palate using your index finger to guide it
- Continue advancement until resistance is felt at the base of the hypopharynx
- Inflate the cuff with the recommended volume of air (check manufacturer guidelines for specific size)
- The device should lift slightly out of the mouth as the cuff inflates properly
- Connect to ventilation circuit and confirm placement
Confirming Correct Placement
- Observe bilateral chest rise with ventilation
- Check for absence of audible leak around the device
- Confirm adequate oxygen saturation
- Verify end-tidal carbon dioxide waveform (capnography)
- Auscultate equal breath sounds bilaterally
- Check that the black line on the tube is aligned with the midline facing the upper lip
Securing the Device
- Secure the LMA with tape or a dedicated holder
- Avoid excessive movement or pressure on the device
- Ensure the tube is not kinked or compressed
- Position the patient's head neutrally to maintain airway patency
Removal Procedure
- Ensure patient is adequately breathing spontaneously
- Remove when protective airway reflexes have returned
- Suction oropharynx if needed before removal
- Deflate the cuff completely
- Remove the device in one smooth motion
- Provide supplemental oxygen and monitor closely
Safety Precautions and Contraindications
Absolute Contraindications
- Patients at high risk of aspiration (full stomach, recent meal, bowel obstruction)
- Pharyngeal pathology or abnormalities
- Limited mouth opening preventing insertion
- Airway obstruction at or below the larynx
Relative Contraindications
- Morbid obesity
- Pregnancy beyond first trimester
- Poor lung compliance requiring high ventilation pressures
- Conditions requiring long procedure duration
Potential Complications
| Complication | Prevention Strategy |
|---|---|
| Aspiration | Proper patient selection, adequate fasting, use ProSeal type when indicated |
| Laryngospasm | Adequate anesthesia depth, gentle insertion, proper removal timing |
| Cuff over-inflation trauma | Use recommended cuff volumes, monitor cuff pressure |
| Malposition | Confirm placement with multiple methods, proper insertion technique |
| Sore throat | Adequate lubrication, gentle insertion, avoid over-inflation |
| Nerve injury | Appropriate size selection, avoid excessive cuff pressure |
Monitoring Requirements
Continuous monitoring must include:
- Oxygen saturation (pulse oximetry)
- End-tidal carbon dioxide (capnography)
- Blood pressure and heart rate
- Respiratory rate and pattern
- Chest movement and breath sounds
- Airway pressures
Frequently Asked Questions
Yes, size 1 LMAs are specifically designed for neonates weighing up to 5 kg. However, special expertise is required due to the delicate anatomy and smaller margin for error in this age group.
While there is no strict time limit, LMAs are typically used for procedures lasting up to 2 to 4 hours. For longer procedures or extended airway management, endotracheal intubation may be preferred.
Both options exist. Classic LMA can be sterilized and reused up to 40 times. Disposable versions (LMA Unique, Supreme) are single-use only. Always follow manufacturer instructions and institutional protocols.
An LMA sits above the vocal cords in the pharynx, while an endotracheal tube passes through the vocal cords into the trachea. LMA insertion is easier and less invasive but provides less protection against aspiration.
Yes, one advantage of the LMA is that it allows both spontaneous breathing and positive pressure ventilation. This makes it suitable for various anesthetic techniques.
First, try repositioning or adjusting cuff inflation. If the leak persists, remove and reinsert the device. If problems continue, consider using a different size or alternative airway management technique.
Follow manufacturer recommendations based on size. Generally: Size 1 (2 to 4 ml), Size 1.5 (4 to 7 ml), Size 2 (10 ml), Size 2.5 (14 ml), Size 3 (20 ml). Never exceed maximum volumes.
When performed under adequate anesthesia or sedation, LMA insertion is not painful. The procedure should never be attempted in an awake or inadequately anesthetized child.
Yes, LMA is an important rescue device in emergency airway management. It is included in difficult airway algorithms and can be life-saving when other airway techniques fail.
Healthcare professionals must receive formal training in airway management, including hands-on practice with LMA insertion under supervision. Regular skill updates and simulation training are recommended.
Device Maintenance and Safety
For Reusable LMAs
- Cleaning: Thoroughly clean immediately after use with enzymatic detergent and warm water
- Inspection: Check for cracks, discoloration, cuff damage, or any wear before each use
- Sterilization: Follow manufacturer guidelines (typically autoclaving at 134 degrees Celsius for 3 to 5 minutes)
- Storage: Store in a clean, dry environment away from direct sunlight and extreme temperatures
- Tracking: Maintain records of number of uses (maximum 40 cycles for most devices)
- Testing: Inflate and deflate cuff before each use to ensure integrity
For Single-Use LMAs
- Verify packaging is intact before opening
- Check expiration date
- Never attempt to resterilize or reuse disposable devices
- Dispose of according to biomedical waste protocols
- Store in original packaging until use
Storage Recommendations
- Maintain storage temperature between 15 to 25 degrees Celsius
- Keep away from direct sunlight and heat sources
- Store in dedicated clean area, separate from contaminated items
- Organize by size for quick access during emergencies
- Ensure easy accessibility in critical care areas
- Regularly check inventory and restock as needed
Quality Assurance
Regular checks should include:
- Monthly inventory review
- Inspection of reusable devices for wear
- Verification of sterilization records
- Staff competency assessments
- Review of adverse events or complications
- Adherence to manufacturer guidelines
Additional Important Information
Pediatric Airway Anatomy Considerations
Children have unique airway characteristics that affect LMA use:
- Larger tongue relative to oral cavity size
- More anterior and superior larynx position
- Shorter neck and trachea
- Softer, more pliable airway structures
- Different shape of epiglottis (omega-shaped in infants)
When to Consider Alternative Airway Management
- Need for high airway pressures (greater than 20 cm H2O)
- Risk of significant aspiration
- Prolonged procedures requiring secure airway
- Abnormal airway anatomy preventing proper seal
- Procedures involving airway surgery
- Requirement for neuromuscular blockade throughout procedure
Emergency Preparedness
Always have immediately available:
- Multiple LMA sizes
- Endotracheal tubes as backup
- Suction equipment
- Bag-mask ventilation system
- Emergency medications
- Difficult airway cart or equipment
Documentation Requirements
Medical records should include:
- LMA type and size used
- Cuff inflation volume
- Insertion attempts and ease of insertion
- Confirmation methods used
- Any complications encountered
- Duration of use
- Removal timing and patient response
Recommended Resources
Official Guidelines and References:
- American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway
- European Resuscitation Council Guidelines on Airway Management
- Pediatric Advanced Life Support (PALS) Provider Manual - American Heart Association
- Brain AIJ. The Laryngeal Mask Airway - A New Concept in Airway Management (original research publications)
- Manufacturer instructions for use (IFU) provided with each device
Professional Organizations:
- Society for Pediatric Anesthesia (SPA)
- American Academy of Pediatrics (AAP) - Anesthesiology Section
- Difficult Airway Society (DAS)
- International Liaison Committee on Resuscitation (ILCOR)
Medical Disclaimer
This guide is intended for educational and informational purposes only and should not replace professional medical training or clinical judgment. The Laryngeal Mask Airway is a medical device that must only be used by appropriately trained and certified healthcare professionals.
Airway management requires comprehensive training, hands-on experience, and ongoing skill maintenance. This information does not constitute medical advice and should not be used as a substitute for proper medical training, institutional protocols, or manufacturer guidelines.
Individual clinical situations may vary, and practitioners should always follow their institution's policies, current clinical guidelines, and exercise professional judgment. The use of LMAs in pediatric patients requires specialized knowledge of pediatric airway anatomy, physiology, and potential complications.
Parents and caregivers should never attempt to use an LMA or any airway device without proper medical training and supervision. In medical emergencies, always contact emergency services immediately.
While every effort has been made to ensure accuracy, medical knowledge and device specifications evolve over time. Always refer to the most current manufacturer instructions, clinical guidelines, and evidence-based resources.
Labels: Critical-Care