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A Comparison of Seal in Seven Supraglottic Airway Devices Using a Cadaver Model of Elevated Esophageal Pressure

Bercker, Sven MD*; Schmidbauer, Willi MD; Volk, Thomas MD; Bogusch, Gottfried PhD§; Bubser, Hans Peter MD; Hensel, Mario MD; Kerner, Thoralf MD

doi: 10.1213/ane.0b013e3181602ae1
Ambulatory Anesthesiology: Research Report

BACKGROUND: Supraglottic airway devices are increasingly important in clinical anesthesia and prehospital emergency medicine, but there are only few data to assess the risk for aspiration. We designed this study to compare the seal of seven supraglottic airway devices in a cadaver model of elevated esophageal pressure.

METHODS: The classic laryngeal mask airway, laryngeal mask airway ProSeal™, intubating laryngeal mask airway Fastrach™, laryngeal tube™, laryngeal tube LTS II™, Combitube™, and Easytube™ were inserted into unfixed human cadavers with an exposed esophagus that had been connected to a water column of 130 cm height. Slow and fast increases of esophageal pressure were performed and the water pressure at which leakage appeared was registered.

RESULTS: The Combitube, Easytube, and intubating laryngeal mask Fastrach withstood the water pressure up to more than 120 cm H2O. The laryngeal mask airway ProSeal, laryngeal tube, and laryngeal tube LTS II were able to block the esophagus until 72–82 cm H2O. The classic laryngeal mask airway showed leakage at 48 cm H2O, but only minor leakage was found in the trachea. Devices with an additional esophageal drain tube drained fluid sufficiently without pulmonary aspiration.

CONCLUSIONS: Concerning the risk of aspiration, the use of devices with an additional esophageal drainage lumen might be superior for use in patients with an increased risk of aspiration. The Combitube, Easytube, and intubating laryngeal mask Fastrach showed the best capacity to withstand an increase of esophageal pressure.

IMPLICATIONS: Using a cadaver model to assess the performance of seven supraglottic airway devices, protection against aspiration can be achieved either by a tight esophageal seal, as was obtained with the Intubating Laryngeal Mask Airway, the Easytube, and the Combitube, or with an esophageal lumen to direct regurgitated fluid out of the mouth.

From the *Department of Anesthesiology and Intensive Care Medicine, Leipzig University Hospital, Germany; †Department of Anesthesiology and Intensive Care Medicine, Bundeswehrkrankenhaus, Berlin, Germany; ‡Department of Anesthesiology and Intensive Care Medicine, Campus Virchow-Klinikum and Campus Charité Mitte, and §Center for Anatomy, Charité-Universitaetsmedizin, Berlin, Germany.

Accepted for publication October 3, 2007.

The first two authors contributed equally to the paper.

All authors disclose financial relationship to the manufacturers of the tested devices or any other conflict of interest.

Address correspondence and reprint requests to Dr. Sven Bercker, Klinik für Anästhesiologie und Intensivtherapie Universitätsklinikum Leipzig, Liebigstr.20, 04103 Leipzig Germany. Address e-mail to

© 2008 International Anesthesia Research Society