Oesophageal Seal of the Novel Supralaryngeal Airway Device I-Gel in Comparison with the Laryngeal Mask Airways Classic and ProSeal Using a Cadaver Model

Background: Supraglottic airway devices are increasingly used in anaesthesia and emergency medicine. This study was designed to investigate the oesophageal seal of the novel supralaryngeal airway device, I-Gel (I-Gel), in comparison with two of the laryngeal mask airways, Classic (cLMA) and ProSeal (pLMA), in a model of elevated oesophageal pressure.

Methods: The three supralaryngeal airway devices were inserted into eight unfixed cadaver models with exposed oesophagi that had been connected to a water column producing both a slow and a fast oesophageal pressure increase. The pressure applied until the loss of oesophageal seal during a slow and fast pressure increase was measured.

Results: During the slow increase of pressure, the pLMA withstood an oesophageal pressure up to a median of 58 cm H(2)O, while the cLMA was able to block the oesophagus up to a median of 37 cm H(2)O, and I-Gel already lost its seal at 13 cm H(2)O. One minute after maximum pressure had been applied, the pLMA withstood an oesophageal pressure of 59 cm H(2)O, the cLMA of 46 cm H(2)O, and I-Gel airway of 21 cm H(2)O. A fast release of oesophageal fluid was accomplished through the oesophageal lumen of both the pLMA and I-Gel.

Conclusions: Both the pLMA and cLMA provided a better seal of the oesophagus than the novel I-Gel airway. The pLMA and I-Gel drain off gastrointestinal fluid fast through the oesophageal lumen. Thus, tracheal aspiration may be prevented with their use. Further study is necessary.