The Use of the Laryngeal Mask in Surgical Tracheostomy

We enjoyed the description of surgical tracheostomy which we feel will be of benefit to trainees of many different specialties. We should like to recommend the use of the flexible laryngeal mask airway (LMA) for selected cases as an alternative to tracheal intubation or local anaesthesia. The LMA has a number of advantages. First, there is no tracheal tube cuff within the surgical field, which, if damaged, risks impaired gas exchange to the patient. Cuff damage can also lead to formation of a bloody aerosol as positive pressure ventilation continues through the tracheal incision.

Second, a tracheal tube must be carefully withdrawn to allow placement of the tracheostomy tube. This results in disturbance to the surgical drapes. We emphasise that this can lead to premature extubation of the patient's trachea at a critical moment, with the very real risk of ensuing hypoxia.

Third, the placement of a tracheal tube within the patient's airway can allow oropharyngeal secretions to accumulate within the larynx and trachea, above the cuff. When the cuff is deflated, these secretions may contaminate the proximal trachea and bronchial tree. The LMA protects against this. Finally, the LMA avoids tracheal intubation, which may be technically demanding in this patient group.

Case selection is important. Use of the LMA is inappropriate when a patient has a full stomach, low respiratory compliance (leading to high inflation pressures during mechanical ventilation) or periglottic pathology which interferes with correct placement of the LMA.

LMA for tracheostomy was originally described in 1992,¹ and a case series reported recently.² We find that the flexible (‘re-inforced’) LMA is the most suitable because the flexible nature of the airway tube allows it (and the attached breathing system) to be positioned out of the operative field.