Designing an Improved Supraglottic Airway for Today’s Anaesthesia Environment Introduction We have now had supraglottic airways, known popularly as laryngeal masks, in everyday anaesthesia practice for over 25 years. There have been several modifications to the LMA over the years – addition of venting ports, intubation aids, camera attachments, ability to use as an endotracheal intubation conduit, camera attachments and so on. Supraglottic airways (SGAs) have proven to be easy to use, robust, versatile and usable in many difficult situations where direct laryngoscopy is difficult or unnecessary (eg. obese patients). They are superior to oral airways and have rendered chin bars, mask straps, Clausen harnesses and oropharyngeal airways virtually obsolete. Nevertheless, there are many additional demands on our supraglottic airways as anaesthesia practice becomes increasingly complex. There are new ventilator modes on our basic anaesthesia ventilators which will allow safe ventilation through a supraglottic airway provided these were modified or redesigned to accommodate these practices. With this in mind, many prototypes of a new, improved airway have been produced to address these specific developments. Gatt S*, Baska K^, Baska M^, Leung D*, Lorenzo M*, vanZundert T +, van Zundert A ** *University of New South Wales, Prince of Wales Hospital, Royal Hospital for Women; ^Liverpool Hospital & Universities of Sydney & New South Wales, Sydney, Australia; + Maastricht University, The Netherlands; ** Catharina-Ziekenhuis, Eindhoven, The Netherlands Conclusion The Baska Mask is equipped with a self-sealing cuff and gastric reflux overflow protection using a sump reservoir and self-venting channels making gastric tube insertion superfluous Acknowledgements The authors wish to thank Drs. Kanag and Meenakshi Baska for many years of dedicated and tenacious service in the pursuit of an improved airway device which addresses some of the shortcomings of earlier models. the Anatomy Department of the School of Medicine of the University of Sydney for producing anatomical specimens suitable for SGA testing and for help with photography of the SGA in place on the anatomical specimens. the Medical Illustrations Unit of the Sydney Children’s and Prince of Wales Hospitals for their assistance with poster preparation. Avantech for the myriad detailed engineering drawings which form the basis for the creation of the silicone models and production moulds for supraglottic airways. A prototype supraglottic airway in place on a cadaver specimen showing lateral fit of the device. Logo of the Baska Supraglottic Airway Device. Anterior view of the improved airway to show the tip of the device, the soft cuffs and the reservoir sump for regurgitant. The Supraglottic Airway Device angulated forwards to show the aperture presented to the laryngeal opening when the airway device is in place. Engineering drawings of one of the multitude of versions of the new laryngeal mask showing some of the new features of the Baska Mask. The prototype mask in place on a sagittal section head and neck anatomical dissection to demonstrate how the mask sits once in position. A lateral view of the improved laryngeal mask to show the channels on the side of the airway which would decompress the stomach. Lateral view of the Baska Airway. Cutout of lateral view to show the internal dimensions and design of the airway and of the tab which allows angulation of the cuffs and tip to allow placement of the Baska Mask in the neutral position. This laryngeal mask is not simply a ‘me too copy’ of previous generations of masks. The Baska Mask has been engineered to address at least some of the shortcomings of the existing laryngeal mask airways – even the newly improved revamps of the original series SGAs. For example, this mask attempts to tackle the perennial problem of the ‘full stomach’ or gastric contents regurgitation by providing a sump reservoir combined with channels on both sides of the airway mask which vent any regurgitant and any secretions / gas / air accumulating in the stomach to the exterior such that soiling of the airway is eliminated. Venting of the stomach in older generation masks relies on the insertion of a gastric drain through a dedicated port in the mask. This mask goes one further. It achieves the same effect with the added advantage of a reservoir. LMAs which require inflation of the cuff are, likewise a potential hazard. Firstly, the airway is not secured until the cuff is inflated. Secondly, the degree of cuff inflation can be very variable across a range of operators such that, often, the cuff is sub-optimally inflated. The soft cuffs of the Baska Mask are always ‘inflated’ even during insertion. Engineering drawing of the lower end of the mask with separate channels for airway and oesophageal vent