The LMA Classic™ as a conduit for tracheal intubation in adult patients: a review and practical guide

Abstract

Unexpected difficulty in maintaining an open airway following induction of anaesthesia remains an ever-present hazard. Repetitive attempts at direct laryngoscopy and intubation are generally acknowledged to be inappropriate. The LMA Classic ™ is recognised as a rescue ventilation device in failed intubation scenarios and its specific role is well defined in international airway management protocols. Should clinical conditions dictate the need for tracheal intubation following placement of an LMA Classic ™ , it may be retained to serve as a conduit for intubation. Utilising the LMA Classic ™ as a conduit for intubation is considered a rescue manoeuvre, only resorted to when conventional methods such as direct laryngoscopy have failed. Therefore, it is important that this approach to intubation has a high success rate and that airway management specialists are familiar with the different available options, the relevant limitations and the pitfalls. A short description of the components of the LMA Classic ™ , specifically relating to its function as an intubating conduit, is provided in this review. Its limitations as a conduit are then listed, followed by a description of the most popular techniques of intubation via the LMA Classic ™ . By adhering to a number of basic principles outlined in this review, limitations may be overcome, pitfalls avoided, and an escape conduit added for the anaesthetist who is faced with a difficult-to-intubate airway.

A cadaver study comparing three fibreoptic‐assisted techniques for converting a supraglottic airway to a cuffed tracheal tube

“…The limitations of the LMA ® Classic and LMA ® Unique as conduits for intubation are well documented and three methods of SAD‐TT conversion using these devices have been described . Previous studies have either compared different SADs in the conversion or have compared performance of novices with experts .…”

Comparison of the paediatric blade of the Pentax-AWS and Ovassapian airway in fibreoptic tracheal intubation in patients with limited mouth opening and cervical spine immobilization by a semi-rigid neck collar: a randomized controlled trial

“…Its limitations include a limited tracheal tube size and difficulty with the removal of the laryngeal mask airway leading to an inadvertent extubation. 38 In contrast, the removal of the paediatric blade of the Pentax-AWS after the insertion of a fibrescope into the trachea was easy, and an adult-sized tracheal tube could be advanced over the fibreoptic bronchoscope.…”

I-Gel versus laryngeal mask airway (LMA) classic as a conduit for tracheal intubation using ventilating bougie

“…Despite these limitations, and in view of its role as an airway rescue device, on occasion, it is still relied on as a conduit for tracheal intubation. [ 5 13 ] i-Gel is a single-use device with a noninflatable cuff, made of thermoplastic elastomer. i-Gel has been reported both as an airway rescue device and as conduit for fiberoptic intubation in predicted difficult airways.…”