Esophageal-Tracheal Combitube

The Esophageal-Tracheal Combitube (manufactured by Covidien-Nellcor in Colorado), a device designed to be inserted blindly, was created to be used with less prerequisite training. The Combitube features two lumens, proximal and distal, with two associated cuffs that allow for ventilation of the patient regardless of esophageal or tracheal insertion. If the distal lumen is placed in the esophagus, the patient is ventilated via the proximal lumen. If the Combitube is inserted and breath sounds are heard when ventilating through the distal lumen, the distal lumen was likely inserted into the trachea. Similar to the LMA, the Combitube can be used without significant neck manipulation in patients who require C-spine precautions. It has the added advantages of aspiration risk reduction and stomach decompression given its two cuffs and lumens.¹⁰ The Combitube is contraindicated in patients with upper esophageal abnormalities, such as esophageal varices, or caustic ingestions.¹¹ As with LMAs, Combitubes are at risk of balloon rupture as well, and attention is needed to avoid damaging the inflating sections of the device both while in storage and during placement. The variation in using the two lumen can also cause confusion.

Laryngeal Tube/King Airway

First invented in Europe in 1999, laryngeal tubes were popularized in the United States by King Systems and are commonly referred to as King airways.⁸ The King LT has distal and proximal cuffs that function to seal the esophagus and hypopharynx, respectively, with a ventilatory lumen located between these cuffs. In contrast to the Combitube, the King LT utilizes one line to inflate both cuffs. The benefits of a King LT include lower inflation pressure and soft distal end, which decrease trauma during insertion and use.¹¹ Due to the presence of inflatable sections, balloon rupture and degradation remain a potential complication, similar to LMAs and the Combitube.

I-Gel

The i-gel was designed in the UK in 2003 and features a gel-style cuff that surrounds the larynx.⁸ Constructed with thermoplastic material, it can take the shape of the patient’s larynx, a design intended to optimize ventilation and minimize aspiration.¹¹ The i-gel features a smaller, secondary lumen running the length of the device, through which a nasogastric tube can be passed. Commonly used in prehospital and hospital settings, the i-gel can facilitate endotracheal intubation and bronchoscopy given its large unobstructed main lumen.¹¹ First-pass success rates are similar when compared to cLMAs and pLMAs and better when compared to the King airway.¹² As a result, the i-gel has found itself in the hands of many prehospital and hospital workers, both in initial and difficult airway management. As there is no inflation step in the placement of i-gel devices, balloon rupture is not a concern and syringes are not required to place the device.