Comparison of Insertion of the Modified i-gel Airway for Oral Surgery With the LMA Flexible: A Manikin Study

We previously modified the i-gel airway to enable its use in the field of oral and maxillofacial surgery and reported its fabrication methods. In general, the standard i-gel airway is quick to insert and has a high success rate, but the modified i-gel airway has yet to be assessed for these attributes. We, therefore, set out to compare the ease of insertion of the modified i-gel airway with the LMA Flexible to investigate the usefulness of the modified i-gel airway. The study participants, who included 20 new interns with no experience using either the LMA Flexible or the modified i-gel airway, inserted each device 3 times into an intubation practice manikin. The variables measured in this study were insertion time and rate of successful insertions. Mean insertion time over 3 attempts was significantly shorter for the modified i-gel™ airway (18.9 ± 4.7 seconds) than the LMA Flexible (24.9 ± 5.1 seconds, P < .001). The rate of successful insertions as a total of all 3 attempts was significantly higher for the modified i-gel airway (56/60 times, 93.3%) than the LMA Flexible (45/60 times, 75%; P = .012). When used by an inexperienced operator, the modified i-gel™ airway is faster and has a higher success rate than the LMA Flexible, suggesting that it can be easily manipulated during insertion.Key Words: Oral and maxillofacial surgery, Supraglottic airway device, Modified i-gel™ airwayThe first laryngeal mask (LMA) was the LMA Classic, developed by Dr Brain. It was later followed by a number of groundbreaking new products, such as the LMA ProSeal, which features a high-pressure seal and a gastric tube orifice, and the LMA Fastrack that can be used to pass an endotracheal tube into the trachea. Today, these and other products comprise the LMA family. One of them, the LMA Flexible (Laryngeal Mask Company, Jersey, UK; Figure 1: top) was developed for oral and maxillofacial surgery and other types of head and neck surgery. The flexible wire-reinforced airway tube of this device has the advantages of avoidance of interference with the operative field, even in oral surgery, and being able to withstand pressure from surgical manipulation.^1,2 Thus, the LMA Flexible is currently the gold standard supraglottic device in the field of oral and maxillofacial surgery. The flexibility of the shaft of the reinforced airway tube, however, makes it difficult to exert any force on the shaft,^1,2 making insertion more difficult than with the LMA Classic.³Open in a separate windowFigure 1.LMA Flexible (top) and modified i-gel airway (bottom).The i-gel airway (Intersurgical Ltd, Wokingham, UK) is a disposable supraglottic device that was developed by Dr Nasir. It consists of an airway tube with a noninflatable gel-like cuff designed to fit perfectly over the larynx and also has a gastric tube orifice. The i-gel airway features a high-pressure seal (pharyngeal leak pressure),⁴ potentially preventing leakage of blood and water into the airway, which is a frequent problem during dental treatment and in oral and maxillofacial surgery. Hence, although this device may be very useful in oral and maxillofacial surgery, its use is limited by the thickness of the shaft of the airway.We previously modified the i-gel airway (modified i-gel airway; Figure 1: bottom) to enable its use in the field of oral and maxillofacial surgery and reported its fabrication methods.⁵ In general, the standard i-gel airway is quick to insert and has a high success rate, but the modified i-gel airway has yet to be assessed for these attributes. We, therefore, set out to compare the ease of insertion of the modified i-gel airway and the LMA Flexible to investigate the usefulness of the modified i-gel airway.