J W McIntyre1. 1. Department of Anaesthesia, University of Alberta, Edmonton.
Abstract
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.
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.