Archie Brain: celebrating 30 years of development in laryngeal mask airways.

The practice of anaesthesia was revolutionised by the ideas of Archie Brain. The routine use of a facemask to manage the airway was not a hands-free technique, despite the development of various harnesses, and made adequate record-keeping difficult. The tracheal tube was associated with some morbidity, which some felt was unsuitable for day surgery. Brain developed an airway management device that was less stressful to the patient than tracheal intubation, and was, however, as safe as using a facemask and airway. Brain also hoped his device would function for cases where mask ventilation was particularly difficult and thus give anaesthetists a safer alternative to a complex intubation, especially in emergency scenarios.

Evolution of the extraglottic airway: a review of its history, applications, and practical tips for success.

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.

The men and history behind the Venturi mask.

The delivery of supplemental oxygen is a critical part in the management of patients presenting with acute hypoxemia. While a number of delivery options are available, one of easiest and least invasive is the simple facemask or "Venturi" mask. Worldwide, these types of masks have been used for over 50 years. Developed initially as simple oxygen-delivery system, the face mask has evolved, acquiring more complexity and efficacy by the application of physical principles in an attempt to provide maximal patient benefit. The original Venturi mask was created by the British physician Earl James Moran Campbell. It was named after the Italian physicist Giovanni Battista Venturi who described the principal of increased velocity of a gas resulting in lower pressures, Campbell incorporated Venturi's principle into the oxygen delivery facemask. By using this principle, precise oxygen delivery occurs, thus, representing the standard of supplemental oxygen facemasks today.

A critique of elective pediatric supraglottic airway devices.

In 1988, when the Laryngeal Mask Airway-Classic (Intavent Orthofix, Maidenhead, UK), was introduced there were only two choices of airway management: tracheal tube or facemask. The supraglottic airway, as we now understand the term, did not exist. Yet, 20 years later, we are faced with an ever increasing choice of supraglottic airway devices (SAD). For many SADs, with the exception of the LMA-Classic and LMA-Proseal (Intavent Orthofix, Maidenhead, UK), there is a lack of high quality data of efficacy. The best evidence requires a randomized controlled trial comparing a new device against an established alternative, properly powered to detect clinically relevant differences in clinically important outcomes. Such studies in children are very rare. Safety data is even harder to establish particularly for rare events such as aspiration. Therefore, most safety data comes from extended use rather than high quality evidence which inevitably biases against newer devices. For reason of these factors, claims of efficacy and particularly safety must be interpreted cautiously. This narrative review aims to present the evidence surrounding the use of currently available pediatric SADs in routine anesthetic practice.

The adult ergonomic face mask concept: historical and theoretical perspectives.

The fundamental skill required of the anesthesiologist and rescuer is to treat upper airway obstruction and maintain adequate ventilation. Adult one-hand face mask ventilation is a complex technique, often applied with suboptimal results. The adult face mask in use today was not designed for one-handed ventilation but inherited its features from the 19(th) century face piece. The airway maneuver used with one-handed ventilation is not standardized. An ergonomic face mask has an asymmetrical dome that accommodates the hand grip required for chin lift and may be better for one-hand ventilation. The historical and theoretical considerations patent to the design and technique of the ergonomic face mask are reviewed.

Oropharyngeal and nasopharyngeal airways: I (1880-1995).

PURPOSE: During the past decade the laryngeal mask airway (LMA) has dominated literature about airways for use during general anaesthesia. The LMA addresses clearly defined clinical objectives. The purpose of this study is to determine whether those objectives were described collectively with reference to earlier airway designs. METHODS: The anaesthesia sections of Index Medicus 1880-1995 were read and publications in the English language about airways were obtained and analysed. Secondary information sources were references to causes of respiratory obstruction. This was supplemented by random reference to available textbooks. RESULTS: The multiple objectives, as least partially, satisfied by the LMA were not described collectively at the time of Hewitt's presentation of an oropharyngeal airway in 1908 and largely were neglected until the present time. CONCLUSION: The design of airways has been based on clinical circumstances and perceived requirements of the time. In contemporary anaesthetic practice, distinct clinical situations still occur and there is a role for different device designs. Currently for supraglottic airway management during general anaesthesia, four types of airway should be available: a Guedel airway, nasopharyngeal airway, a laryngeal mask airway, and an airway specifically designed to facilitate blind tracheal intubation.

Use of the laryngeal mask airway in otolaryngology.

The laryngeal mask airway (LMA) provides a third type of airway for consideration in otolaryngology that offers some of the benefits of intubation and avoids many of the associated hazards. It can be inserted without the use of a laryngoscope or muscle relaxant, and is designed to produce an airtight seal around the laryngeal inlet. The LMA provides a secure airway suitable for spontaneous or controlled ventilation, acts as an airtight throat pack, and is well tolerated during recovery. The reinforced LMA (RLMA), specifically designed for otolaryngology anaesthesia, has recently become available. The purpose of this article to is provide a brief overview of the LMA with special emphasis on its use in otolaryngology--head and neck surgery.