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The tracheal-esophageal Combitube has two inflatable balloons and two lumens. It is designed to seal the upper airway and isolate the tracheal and esophagus. It accomplishes this with one balloon in the esophagus and a second balloon in the pharynx; the ventilation holes between the two balloons are positioned at the laryngeal inlet.
Combitube enters esophagus in >95% of cases; ventilation is through lumen #1 (blue connector) via supraglottic holes located between balloons. NOTE: Ventilation (end-tidal CO2 detection, pulse oximetry, etc.) must be confirmed for all placements, like a tracheal tube. In one in twenty insertions the Combitube enters the trachea–if this occurs ventilation of the lungs will only occur through lumen #2.
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Combitube in esophagus. |
The Combitube is comparable to a tracheal tube in terms of gas exchange and oxygenation. The Combitube's ability to effectively ventilate and prevent aspiration has made it useful in the management of failed airways and as a primary means of airway management in cardiac arrest.
Because the Combitube is designed for the insertion into the esophagus, its use is contraindicated in hiatal hernia, esophageal pathology, caustic ingestions, and patients below four and a half feet tall. The Combitube is now offered in two sizes (37 F vs. 41 F). The smaller size has dimensions only slightly smaller than the original larger size, but the tube is significantly more flexible. Apart from extremely tall individuals (>6.5 feet), the Small Adult size is now recommended by the inventor (Dr. Michael Frass) for all adults.
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Combitube –2 lumens, 2 balloons:
1) Twin-lumen device with two balloons: balloon #1 (beige) seals pharynx, balloon #2 (white) seals esophagus.
2) Lumen #1 (blue proximal connector) goes to ventilation holes between balloons, while lumen #2 (clear proximal connector) runs completely through to distal tip.
3) Excellent seal pressures, trachea fully isolated from esophagus.
Combitube sizes, insertion and ventilation technique:
1) Two sizes: SA (small adult, 37 Fr) and Adult (41 Fr). SA size recommended for adults less than 6.5 feet. Adult size has high rate of insertion failure (~20%). Absent gag reflex required. Contraindicated with esophageal pathology, caustic ingestions, height < 4.5 feet.
2) Insertion technique: with balloons deflated and device lubricated, lift mandible, blindly insert until dental lines (thick black lines) are at teeth or gum line.
3) Inflate balloon #1(beige, pharyngeal balloon, 85 cc for SA size), then inflate balloon #2 (white, esophageal balloon, 12 cc for SA size). Over-inflated esophageal balloon can occlude trachea (by collapsing the posterior membraneous trachea from behind).
4) Ventilate lumen #1 (blue connector) and verify adequate ventilation through clinical signs and confirmatory method (end-tidal CO2, esophageal intubation detector).
5) Nasogastric tube can be inserted down lumen #2 (clear connector) for stomach decompression.
6) If ventilation not confirmed, switch bag to lumen #2 (clear); device may have gone into trachea. Verify adequate ventilation.
7) If switching lumen does not create adequate ventilation, deflate balloons, withdraw device 3 cm and retry ventilation. Pharyngeal balloon pressing down on epiglottis may have occluded airway. |
King LT