Laryngeal mask and tracheal intubation are the two most commonly used airway management
methods for patients under general anesthesia. Compared with tracheal intubation,
laryngeal mask is only placed in the throat without the need for laryngoscope to expose
the glottis, not entering the glottis and trachea, so it will not cause mechanical damage
to the vocal cords and trachea. Moreover, the insertion of laryngeal mask reduces the
excitation of sympathetic and vagus nerves, has a relatively mild effect on physiological
status, and significantly reduces cardiovascular reactions, which is convenient for
maintaining hemodynamic stability during anesthesia induction and patients can tolerate
the tube better without coughing or agitation during recovery from the anesthesia.
Therefore, laryngeal masks are currently widely used in airway management during general
anesthesia. Studies have shown that about 3 million patients in the UK National Health
Service system receive anesthesia surgery with different types of airway management every
year, and the use of laryngeal masks is higher than that of tracheal intubation,
accounting for about 56.2%.
Since its introduction, many new laryngeal masks have been improved and applied to
clinical practice based on the classic laryngeal mask. A key indicator for evaluating the
performance of laryngeal masks is their sealing effect on the airway. Currently,
laryngeal masks are mainly divided into two categories: inflatable laryngeal masks and
non-inflatable laryngeal masks. Inflatable laryngeal masks are traditional types,
including BlockBuster, Superme, ProSeal, and Fastrach, which are the most widely used in
clinical practice. Non-inflatable laryngeal masks are designed with a mirror image of the
throat opening and use thermoplastic elastomer materials to achieve a gas tightness
effect similar to that of inflatable laryngeal masks. The i-gel laryngeal mask is
currently the most commonly used non-inflatable type. A meta-analysis found that the
sealing pressure of the i-gel laryngeal mask is higher than that of traditional
inflatable laryngeal masks, indicating better airway sealing performance for
non-inflatable laryngeal masks. The GMA-TULIP non-inflatable laryngeal mask is a new type
of non-inflatable laryngeal mask with advantages such as a C-shaped double gastric tube
channel, a stable platform for the tongue base, a soft tissue sealing ring, a prominent
epiglottis attachment, and a design that matches the anatomical structure of the throat
opening. Compared with inflatable laryngeal masks, the GMA-TULIP mask is more in line
with anatomical positioning design, theoretically providing higher sealing effect on the
airway.
Although the laryngeal mask has been successfully applied to the airway management of
surgeries with lateral position under general anesthesia, its widespread use is limited
due to the special position of lateral position, which may lead to laryngeal mask
displacement, poor airway tightness, and air leakage. Therefore, exploring a laryngeal
mask with better airway sealing effect in surgeries with lateral position under general
anesthesia will help promote the clinical application of laryngeal mask, reduce airway
injury and hemodynamic fluctuation, and improve patient comfort. To this end, this
project plans to compare the application effects of traditional inflatable BlockBuster
laryngeal mask, i-gel non-inflatable laryngeal mask, and GMA-TULIP non-inflatable
laryngeal mask in surgeries with lateral position under general anesthesia, providing
clinical evidence for the selection of laryngeal mask in surgeries with lateral position
under general anesthesia.