Transcript No Slide Title

Designing an Improved Supraglottic Airway for
Today’s Anaesthesia Environment
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
Introduction
Anterior view of the improved airway
to show the tip of the device, the soft
cuffs and the reservoir sump for
regurgitant.
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.
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.
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.
The Supraglottic Airway
Device angulated forwards to
show the aperture presented to
the laryngeal opening when
the airway device is in place.
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.
With this in mind, many prototypes of a new, improved airway
have been produced to address these specific developments.
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.
A prototype
supraglottic
airway in place on
a cadaver
specimen showing
lateral fit of the
device.
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.
Engineering drawings of one of the multitude of
versions of the new laryngeal mask showing some of
the new features of the Baska Mask.
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.
Lateral view of the Baska
Airway.
Logo of the Baska
Supraglottic
Airway Device.
Engineering drawing of the lower end of the mask with
separate channels for airway and oesophageal vent
A lateral view of
the improved
laryngeal mask to
show the channels
on the side of the
airway which
would decompress
the stomach.
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
The prototype
mask in place on
a sagittal section
head and neck
anatomical
dissection to
demonstrate how
the mask sits
once in position.
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.