Airway Skills 6:
Esophageal Tracheal Combitube
The esophageal tracheal combitube (Combitube™) is a two-barreled tube that functions well when placed in either the trachea or the esophagus. Insertion does not require neck movement. Note: The short white tube is connected to the end of the tube; the long blue tube is connected to the side holes located between the two balloons.
- The tube is placed blindly with care to keep it midline. It is placed to a depth that lines up the teeth between the 2 proximal markings on the tube. Placing the tube too deeply will occlude the larynx.
- The large 100 cc balloon is inflated in the posterior pharynx; the 15 cc distal balloon is then inflated. While the large cuff is inflating, it will want to move the Combitube in or out. It is conforming to the posterior pharynx and palate. Let it move.
- The short white tube is continuous with the distal opening of the tube. Attach an esophageal intubation detector (EID) and test it for position. Do it twice if the patient has been bag-valve-mask ventilated. Alternatively, simply begin ventilation through the long blue tube and observe for chest rise and listen for breath sounds. About 90% of the time, the Combitube will be in the esophagus. If the tube does not function, it is probably in the trachea.
- If the tube is in the trachea, use it like an endotracheal tube. Ventilate through the short white tube. The large balloon stabilizes the Combitube and keeps it in correct position.
If the Combitube is functioning well, there is no need to replace it during resuscitation or for transfer. However, to avoid error, bend the unused tube down and tape it there.
To replace the Combitube with a regular ET tube when it is located in the trachea, pass an ET tube introducer (ETI) through the white tube and remove the Combitube. Pass a regular ET tube into the trachea over the ETI.
It the Combitube is in the esophagus, and you wish to replace it with an ET tube, the trachea can be intubated with difficulty without removing the tube. Deflate the large balloon and move the tube to the side of the mouth. Use a laryngoscope to visualize the larynx by lifting the base of the tongue. The deflated large balloon can still obstruct your vision. If this occurs, rotate the Combitube to change the orientation of the deflated balloon. Intubate with the aid of an ETI.
Alternatively, pass a lubricated 14 French gastric tube through the white tube to evacuate the esophagus and stomach. Deflate both balloons, remove the esophageal tracheal Combitube, and intubate as usual.
The Combitube is almost an ideal rescue airway. The availability of a Combitube makes rapid sequence intubation a safe procedure. The standard size will function well in almost any adult. The smaller size is available for persons between 4- and 5-feet tall. Many Asian and Hispanic patients may be less than 5-feet tall. The volume of air in the large balloon is reduced to 80 cc in the 4-feet tall model.
If the patient is conscious, the Combitube is uncomfortable. Sedation is needed. A Combitube is not adequate to ventilate a patient with laryngospasm unless paralysis is used. Laryngeal edema is a relative contraindication. The latex balloon may be a problem in latex-sensitive individuals.
The Combitube is not suitable for use over a long period (over about 2 to 3 hours). The Combitube is difficult to use with a ventilator because its deadspace requires a large tidal volume. The Combitube offers slight resistance to exhalation when placed in the esophagus, so it may have a PEEP effect.
References
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Staudinger T, Brugger S, Watschinger B, et al. Emergency intubation with the Combitube: comparison with the endotracheal airway. Ann Emerg Med. 1992;22:1573-1575.
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Frass M, Frenzer R, Mayer G, et al. Mechanical ventilation with the esophageal tracheal combitube (ETC) in the intensive care unit. Arch Emerg Med. 1987;4:219-225.