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Evidence summaries

Laryngeal Mask Airway (Lma) Compared to Tracheal Tube (Tt) or Facemask (Fm)

The benefits of laryngeal mask airway appear to include increased speed and reliability of placement by inexperienced personnel at resuscitation, haemodynamic stability, less coughing and sore throat. Its disadvantage is an increased likelihood of leak and gastric insufflation. Level of evidence: "B"

A systematic review 1 including 52 studies with a total of 2,440 subjects was abstracted in DARE. 35 studies compared LMA with TT, 14 compared LMA with FM, 1 study compared LMA with TT and FM, and 2 studies compared LMA with combined TT/FM where TT was replaced with FM in an emergency.

LMA was better in ease and time of placement for non-anaesthetists, but there was no significant difference for anaesthetists. LMA was better in ease but not time for placement for non-anaesthetists.

LMA was better than TT in terms of pulse rate and blood pressure changes during insertion and emergence (p<0.001). There was no significant difference between LMA and FM.

There was no significant difference in the work of breathing between LMA and TT. TT was better in terms of leak and gastric insufflation (both p<0.005).

There was a lower frequency of cough with LMA compared with TT (p<0.001), no significant difference in frequency of laryngospasm, and no significant difference in oxygen saturation. LMA conferred advantage over FM in oxygen saturation (p<0.025).

Comment: The quality of evidence is downgraded by study quality.

    References

    • Brimacombe J. The advantages of the LMA over the tracheal tube or facemask: a meta-analysis. Can J Anaesth 1995 Nov;42(11):1017-23. [PubMed][DARE]

Primary/Secondary Keywords