title: Evolution of the extraglottic airway: a review of its history, applications, and practical tips for success.
abstract: The development of the laryngeal mask airway in 1981 was an important first step toward widespread use and acceptance of the extraglottic airway (EGA). The term extraglottic is used in this review to encompass those airways that do not violate the larynx, in addition to those with a supraglottic position. Although the term extraglottic may be broad and include airways such as tracheostomy tubes, the term supraglottic does not describe a large number of devices with subglottic components and is too narrow for a discussion of modern devices. EGAs have flourished in practice, and now a wide variety of devices are available for an ever-expanding array of applications. In this review we attempt to clarify the current state of EGA devices new and old, and to illustrate their use in numerous settings. Particular attention is paid to the use of EGAs in special situations such as obstetric, pediatric, prehospital, and nontraditional "out of the operating room" settings. The role of the EGA in difficult airway management is discussed. EGA devices have saved countless lives because they facilitate ventilation when facemask ventilation and tracheal intubation were not possible. Traditionally, difficult airway management focused on successful tracheal intubation. The EGA has allowed a paradigm shift, changing the emphasis of difficult airway management from tracheal intubation to ventilation and oxygenation. EGA devices have proved to be useful adjuncts to tracheal intubation; in particular, the combination of EGA devices and fiberoptic guidance is a powerful technique for difficult airway management. Despite their utility, EGAs do have disadvantages. For example, they typically do not provide the same protection from pulmonary aspiration of regurgitated gastric material as a cuffed tracheal tube. The risk of aspiration of gastric contents persists despite advances in EGA design that have sought to address the issue. The association between excessive EGA cuff pressure and potential morbidity is becoming increasingly recognized. The widespread success and adoption of the EGA into clinical practice has revolutionized airway management and anesthetic care. Although the role of EGAs is well established, the user must know each device's particular strengths and limitations and understand that limited data are available for guidance until a new device has been well studied.
authors.affiliation: Department of Anesthesia and Critical Care, The University of Chicago Medical Center, Chicago, IL 60637, USA. mhernandez@dacc.uchicago.edu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hernandez
authors.forename: P Allan
authors.initials: PA
authors.lastname: Klock
authors.forename: Adranik
authors.initials: A
authors.lastname: Ovassapian
mesh_terms: D000758:Anesthesia / Q000009:adverse effects / Q000266:history; D004867:Equipment Design; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D017214:Laryngeal Masks / Q000009:adverse effects / Q000266:history; D018579:Patient Selection; D012121:Respiration, Artificial / Q000009:adverse effects / Q000266:history / Q000295:instrumentation*; D018570:Risk Assessment; D012307:Risk Factors