What are the key considerations for managing a patient's airway with a supra glottic airway device, including proper sizing, labeling, and medication use?

Supraglottic Airway Devices: Comprehensive Management Guide

Supraglottic airway devices (SADs) should be selected based on generation type, with second-generation devices being preferred for their improved safety profile and gastric access capabilities. 1

Device Selection and Sizing

Types of Supraglottic Airways

• First-generation SADs: Basic ventilation channel without gastric access
• Second-generation SADs: Include gastric channel for catheter insertion and improved seal design
• Third-generation SADs: Feature vision-guided systems for placement verification 2

Proper Sizing Guidelines

• Pediatric sizing:
  • Size 1: Neonates/infants up to 5 kg
  • Size 1.5: Infants 5-10 kg
  • Size 2: Infants/children 10-20 kg
  • Size 2.5: Children 20-30 kg
  • Size 3: Children 30-50 kg 1
• Adult sizing:
  • Size 3: Small adults 30-50 kg
  • Size 4: Medium adults 50-70 kg
  • Size 5: Large adults 70-100+ kg 1

Indications and Contraindications

Primary Indications

• Routine anesthesia in spontaneously breathing or ventilated patients
• Difficult airway rescue when intubation fails
• Conduit for endotracheal intubation
• Bridge to extubation
• Pre-hospital emergency airway management 1

Contraindications

• Patients at high risk for aspiration (non-fasted, morbidly obese, pregnancy >14 weeks)
• Patients with significantly decreased lung compliance
• Fixed upper airway obstruction
• Mouth opening <1.5 cm 3

Proper Insertion Technique

Preparation

1. Select appropriate size based on patient weight
2. Inspect device for defects
3. Fully deflate cuff to create smooth leading edge
4. Lubricate posterior surface with water-soluble lubricant

Insertion Steps

1. Position patient in "sniffing position" if cervical spine is intact
2. Open mouth with non-dominant hand
3. Insert device following manufacturer's recommendations (typically posterior curvature against hard palate)
4. Advance until resistance is felt
5. Inflate cuff to recommended pressure (typically 60 cmH₂O)
6. Verify proper placement:
   • Bilateral chest rise
   • End-tidal CO₂ confirmation
   • No leak around cuff during positive pressure ventilation 1, 4

Management Considerations

Ventilation Parameters

• Maintain peak airway pressures <20-25 cmH₂O to minimize leaks
• Consider pressure-controlled ventilation rather than volume-controlled
• Monitor for adequate tidal volumes and oxygenation 1

Cuff Management

• Maintain intracuff pressure at 60 cmH₂O initially
• Monitor pressure throughout procedure as it may increase over time (particularly with N₂O use) 5
• Avoid excessive cuff pressures which can cause pharyngeal morbidity

Using SAD as Intubation Conduit

• Second-generation devices are preferred for this purpose
• Use flexible intubation scopes through the ventilation channel
• Consider specialized intubating SADs (like LMA Fastrach) for difficult airways 1

Troubleshooting Common Issues

Inadequate Seal/Ventilation

1. Reposition device
2. Try different size (usually larger)
3. Increase cuff pressure slightly (not exceeding 60 cmH₂O)
4. Consider switching to alternative airway device if unsuccessful 6

Difficulty with Gastric Tube Placement

1. Ensure proper SAD positioning first
2. Use well-lubricated appropriate size gastric tube
3. Second-generation SADs have higher success rates for gastric tube placement 5

Airway Obstruction

1. Adjust head/neck position
2. Ensure appropriate depth of anesthesia
3. Consider jaw thrust maneuver
4. Rule out device malposition or airway pathology 1

Special Considerations

Difficult Airway Management

• SADs provide successful rescue ventilation in >90% of can't-intubate scenarios
• Include SADs in difficult airway algorithms
• Consider having multiple types/sizes available 1

Use During CPR

• SADs provide rapid airway access during resuscitation
• Second-generation devices preferred due to higher seal pressures
• Consider as bridge until definitive airway can be established 1

Bronchoscopic Procedures

• SADs can facilitate bronchoscopic interventions, especially for upper tracheal lesions
• Provides access while allowing ventilation
• Particularly useful for subglottic and upper tracheal stenotic lesions 7

Labeling and Packaging Information

Critical Information on Packaging

• Device size (numerical and weight-based)
• Single-use vs. reusable designation
• Maximum cuff inflation volume
• Maximum intracuff pressure
• Latex content information
• Sterilization status and method
• Expiration date 4

Device Markings

• Size indicator on the device body
• Depth markers
• Bite block indicators
• Maximum fill line on pilot balloon
• Manufacturer's logo and model identifier 4

Potential Complications and Prevention

Aspiration Risk

• Use second-generation devices with gastric access
• Insert gastric tube to decompress stomach
• Maintain appropriate depth of anesthesia
• Consider rapid sequence induction with tracheal intubation for high-risk patients 6

Airway Trauma

• Ensure proper lubrication
• Avoid forceful insertion
• Use appropriate size
• Monitor cuff pressures
• Remove with cuff partially deflated 3

Nerve Injuries

• Avoid excessive cuff pressures
• Proper positioning to prevent compression of lingual, hypoglossal, or recurrent laryngeal nerves
• Limit duration of use when possible 6

By following these guidelines for supraglottic airway device selection, insertion, and management, clinicians can effectively utilize these important tools while minimizing potential complications and optimizing patient outcomes.