What is a Supraglottic Airway (SGA)?
A supraglottic airway device (SGA) is a medical tool used to secure and maintain a patient's airway during anesthesia or in an emergency. Unlike an endotracheal (ET) tube, which passes through the vocal cords and into the trachea, an SGA sits above the glottis (the opening of the vocal cords). It provides a bridge between a manual ventilation bag and the patient's trachea, ensuring oxygen can enter the lungs effectively. The IGEL is a second-generation SGA, incorporating design improvements over earlier devices like the classic laryngeal mask airway (LMA).
The Unique Features of the IGEL
Manufactured from a medical-grade thermoplastic elastomer, the IGEL is designed to mirror the natural perilaryngeal anatomy. This soft, gel-like material allows it to create a reliable seal without the need for an inflatable cuff, a key differentiator from many first-generation SGAs.
Key features that define its advanced design include:
- Non-Inflatable Cuff: The soft, gel-like cuff conforms naturally to the airway structures, which reduces the risk of compression trauma and nerve injuries often associated with over-inflated cuffs.
- Gastric Channel: Most IGEL sizes (except for the smallest) include a built-in channel that allows for the passage of a nasogastric tube. This feature helps to vent gastric pressure, decompress the stomach, and provides a route for early detection of regurgitation, significantly reducing the risk of aspiration.
- Integral Bite Block: A strengthened part of the device prevents patients from biting down and occluding the airway, protecting both the patient and the device.
- Epiglottic Rest: This design element helps prevent the epiglottis from folding down and obstructing the airway opening.
- Buccal Cavity Stabilizer: This feature helps guide the device during insertion and prevents it from rotating once in place.
Clinical Uses and Applications
The IGEL's design makes it suitable for a variety of clinical situations, from routine anesthesia to life-saving emergencies. Its applications include:
- Routine Anesthesia: For short to medium-length surgical procedures in patients who have fasted, the IGEL is an efficient and effective airway management solution.
- Emergency Airway Management: Paramedics and other advanced EMS personnel can use the IGEL in the field for cardiac arrest patients or other unconscious individuals requiring immediate airway control.
- Rescue Airway: It is indicated for use in situations where endotracheal intubation has been attempted but has failed. Its blind insertion technique and speed are critical in these scenarios.
- Conduit for Intubation: For certain adult sizes, the IGEL can act as a guide for more definitive airway management, such as fibreoptic-guided tracheal intubation.
IGEL vs. Classic LMA: A Comparison
The IGEL's second-generation design offers several improvements over older, first-generation devices like the Classic Laryngeal Mask Airway (LMA). The comparison below highlights some key differences:
| Feature | IGEL (Second-Generation) | Classic LMA (First-Generation) |
|---|---|---|
| Cuff Type | Non-inflatable, thermoplastic elastomer gel | Inflatable, reusable or disposable |
| Insertion | Faster and often easier due to anatomical shape and lack of cuff inflation | Slower due to need for manual cuff inflation after insertion |
| Trauma | Reduced potential for compression trauma, sore throat, and nerve injury | Higher risk of mucosal injury or nerve damage from cuff over-inflation |
| Gastric Channel | Integrated gastric access in most sizes for suction and venting | Generally lacks a dedicated gastric channel, increasing aspiration risk |
| Bite Block | Built-in integral bite block | Requires a separate bite block to prevent occlusion |
| Clinical Performance | Comparable or improved success rates and leak pressures | Well-established but can have slower insertion times and may be more sensitive to position |
Contraindications and Cautions
While highly effective, the IGEL is not suitable for all patients. Contraindications include:
- Intact Gag Reflex: A conscious or semi-conscious patient with an active gag reflex is not an appropriate candidate for an IGEL.
- Known Esophageal Disease: Patients with pre-existing esophageal conditions may not be suitable for this device.
- Obstructive Lesions Below the Glottis: Any obstruction below the laryngeal inlet would prevent proper ventilation.
- Limited Mouth Opening or Trismus: A patient with reduced ability to open their mouth makes insertion difficult or impossible.
- Caustic Ingestion or Airway Burns: Chemical or thermal injury to the airway is a contraindication due to potential trauma and tissue damage.
Clinicians must also be mindful of potential complications like poor capnography readings, excessive leaks, or failed placement, which may require a more definitive airway.
Conclusion: What is an IGEL Considered?
Ultimately, what an IGEL is considered is a versatile and innovative second-generation supraglottic airway device that has significantly impacted modern airway management. Its key innovations—a soft, non-inflatable cuff, an integrated gastric channel, and a built-in bite block—have addressed many of the limitations of earlier devices. As a reliable alternative in both routine and emergency settings, the IGEL provides a quicker, easier, and less traumatic method for securing a patient's airway, cementing its role as an essential tool for healthcare providers.
For more technical information, one can consult the manufacturer's resources, such as those provided by Intersurgical.
