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.

Keywords: laryngeal mask airway; intubation; intubating conduit; bougie; catheter; guidewire; failed intubation; difficult airway