Clinical evidence

Evidence Search

Supraglottic airway devices: recent advances

Authors

Cook T., Howes B.

Publication

Contin Educ Anaesth Crit Care Pain 2011; 11 (2): 56-61.

Summary

  • A review of the recent advances in supraglottic airway devices
  • Although the LMA ProSeal™ has not been shown to outperform the LMA Classic™, its efficacy and safety has been demonstrated in routine and advanced use
  • There is evidence showing that other second-generation supraglottic airway devices, including the LMA Supreme™, can effectively compete with the LMA Classic™ and LMA ProSeal™

Findings:

Introduction

  • The LMA Classic™ is a first-generation supraglottic airway device that was first introduced into clinical practice over 25 years ago
  • Several second-generation devices, including the LMA ProSeal™, LMA Supreme™, i-gel™ and Laryngeal Tube Suction™ II, have been introduced over the past decade
  • These newer devices have design features that may offer efficacy and safety advantages over the LMA Classic™ in the setting of in-hospital anaesthesia in patients undergoing elective surgery

Limitations of the LMA Classic™

  • Although the LMA Classic™ is used in an estimated 50% of cases requiring airway management, it has several limitations
    • It has a moderate pharyngeal seal (~20 cm H2O)
    • It may be associated with pulmonary aspiration of regurgitated fluid

Alternatives to the LMA Classic™

LMA ProSeal™

  • The features of the LMA ProSeal™ are shown in Table 1
  • Data show that specific features of the LMA ProSeal™ may reduce the risk of pulmonary aspiration compared with the LMA Classic™
  • This is primarily due to the addition of
    • A posterior cuff and a larger and deeper bowl, which results in a better airway seal and allows higher leak pressures during positive pressure ventilation (reducing the risk of gastric insufflation)
    • An oesophageal drain tube, which isolates the gastrointestinal and respiratory tracts (reducing the risk of [i] gastric insufflation [by venting any gas leaking into the oesophagus] and [ii] aspiration in the case of regurgitation [by venting fluid beyond the pharynx])
  • There is a sizeable amount of data to support the efficacy and safety of the LMA ProSeal™, including in patients with difficult airways

 

LMA Supreme™

  • The LMA Supreme™ combines the features of multiple LMA devices, including the LMA ProSeal™, LMA Fastrach™ and LMA Unique™ (Table 1)
  • The LMA Supreme™ has a seal that is intermediate between the LMA Classic™ and the LMA ProSeal™ and its features mean that it theoretically offers good protection against aspiration
  • As yet, there are limited data regarding the use of the LMA Supreme™ in advanced settings or in patients with difficult-to-manage airways

 

i-gel™

  • The features of the i-gel™ are shown in Table 1
  • Like the LMA ProSeal™ and LMA Supreme™, the i-gel™ contains a drain tube, which has been shown to protect against aspiration and give an early indication of regurgitation
  • Although the i-gel™ is considered easy to insert, rates of failed ventilation appear to be higher than those with the LMA ProSeal™ (potentially because of the lack of an inflatable cuff)

 

Laryngeal Tube Suction™ II

  • The Laryngeal Tube Suction™ II has a high oropharyngeal seal and insertion of the device is considered easy
  • Post-insertion ventilation is less reliable than that with the LMA ProSeal™, the device is associated with a relatively high rate of airway obstruction and occasional glottic placement has been reported
  • The small airway orifice limits the functionality of the device as a conduit

Implications:

  • Although there is insufficient evidence to suggest that newer, second-generation supraglottic airway devices are better than the first-generation LMA Classic™, the efficacy and safety of the LMA ProSeal™ has been demonstrated in routine and advanced use
  • Increasing positive evidence suggests that other second-generation supraglottic airway devices, including the LMA Supreme™, can compete effectively with both the LMA Classic™ and LMA ProSeal™