The disclosed laryngeal mask airway device includes a mask portion and an airway tube. The mask portion includes an inflatable cuff, which defines a central opening when the cuff is inflated. The airway tube defines an internal passage extending from a proximal end of the tube to a distal end of the tube. The airway tube further defines two or more tabs disposed near the distal end of the tube. The mask portion is coupled to the airway tube near the distal end of the airway tube, and the tabs extend from the airway tube into the central opening defined by the cuff when the cuff is inflated.

A laryngeal-mask airway device including provision for drainage of the oesophagus comprises an inflatable main-cuff and a backplate having a laryngeal-side and a pharyngeal-side. The backplate also has an external tube-joint adjacent to the proximal region of the main-cuff. The backplate is hermetically bonded to the periphery of the main-cuff establishing separation between a laryngeal-chamber region and a pharyngeal region. An distally open evacuation tube includes a distal portion which longitudinally traverses the interior of the distal region of the main-cuff in sealed relation therewith for operative engagement and communication with the inlet of the oesophagus. The evacuation tube traverses the laryngeal-chamber region generally adjacent to the laryngeal-side of the backplate and passages through a proximally located tube-joint to the pharyngeal region. An airway tube also extends into the tube-joint for communication with an airway port to provide a flowpath between the airway tube and laryngeal-chamber region.

A reversibly operable motor is mechanically connected to automatically position the piston of an air syringe that is pneumatically connected to the inflatable/deflatable seal ring or cuff of a laryngeal mask airway device (LMA) that is installed in a patient, who is being ventilated and/or anaesthetized via the airway of the LMA device. Air pressure in the cuff corrected as necessary to conform to a predetermined pressure level. The system continuously monitors for abnormal patterns of response, with audibly and visually reported warnings to the anaesthetist; these warnings include system detection of a patient's incipient sign of premature awareness while still under surgery, system detection and warning of a system or LMA malfunction, and continual microprocessor survey and integration of historical data to determine decremental recovery from administered anaesthesia.

The disclosed method of monitoring the cuff pressure of an LMA provides an estimation of a patient's anesthetic state. Cuff pressure tends to rise and fall during IPPV and spontaneous breathing. One of the disclosed methods activates an alarm if an instantaneous value of the cuff pressure exceeds selected levels. This method may also automatically adjust the selected levels. One of the disclosed methods activates an alarm if activity of the cuff pressure as observed over a period of time exceeds a selected level.

A modified laryngeal mask airway device (LMA-device) is provided with means to improve ease of insertion, reliability of function and higher seal pressure (i.e., cuff pressure ratio). The LMA-device includes an indented section of the airway tube to offer locating means and purchase for the inserting finger, and extended mask aperture bars to increase the effective ventilating area of the mask and reduce the possibility of epiglottis displacement occasioned by mask insertion. The LMA-device further includes a modification of the airway tube angle of attachment to the mask, and provision of a posterior or back-cushion covering the entire posterior surface of the mask.