The Esophageal-Tracheal Combitube (ETC; Medtronics, Minneapolis, MN) and the EasyTube (EzT; Rusch, Kernen, Germany) are double lumen airway devices that can be blindly inserted into the unconscious and unresponsive patient. The ETC and EzT function to adequately ventilate and oxygenate a patient while simultaneously protecting the airway from aspiration.1,2 They are most often used in the prehospital setting by Emergency Medical Technicians not trained in standard orotracheal intubation and by paramedic-level rescuers as an alternative airway device when standard orotracheal intubation fails.3-6 These devices are used in the Emergency Department primarily as a rescue airway. These are the only two double lumen devices used in the prehospital setting and the Emergency Department. The Emergency Physician should be familiar with these devices so that they can be removed and exchanged with an endotracheal tube if placed in the prehospital setting or if required to manage a difficult airway.
ANATOMY AND PATHOPHYSIOLOGY
The ETC is a double-tube, double lumen, and double-cuffed device (Figure 27-1). The ETC starts as two distinct tubes that fuse into one but remain functionally separated by a partition. The shorter clear tube is continuous with the distal open port and is known as the tracheoesophageal lumen. At its distal end is the distal tracheoesophageal cuff, similar to that of an endotracheal tube. It is a high-volume, low-pressure cuff that is inflated through the white inflation port. The longer blue tube is continuous with the eight perforations known as the proximal ports. A large pharyngeal cuff is just proximal to the perforations. This cuff is positioned between the base of the tongue and the palate. It separates the oral and nasal cavities from the remainder of the airway. It is inflated through the blue inflation port.
The Combitube. A. Photograph. B. Illustration.
The EzT is also a double-tube, double lumen, and double-cuffed device with a structure similar to the ETC (Figure 27-2). It has several differences in comparison to the ETC (Table 27-1). The shorter clear tube ends as a conventional single-lumen 7.5 mm endotracheal tube. The EzT may be used as a primary airway device under direct laryngoscopy. When placed successfully into the trachea, it functions as a 7.5 mm endotracheal tube. If unable to pass it into the trachea, it can be advanced into the esophagus and the patient ventilated through the blue tube.7,8 The longer blue tube ends in an open aperture rather than multiple perforations. The EzT is latex free.7
TABLE 27-1Features of Double Lumen Airway Tubes