Impossible insertion of the laryngeal mask airway and oropharyngeal axes

Abstract

The laryngeal mask airway (LMA) has been used widely for airway management during general anesthesia in the last decade. There have been reports in which the LMA successfully secured the airway as an alternative and as an aid to anticipated difficult tracheal intubation in patients with ankylosing spondylosis of the cervical spine or atlantooccipital joint due to severe rheumatoid arthritis. However, Pennant and White suggested that the use of the LMA is contraindicated in patients who are unable to extend the neck because of ankylosing spondylitis, severe rheumatoid arthritis, or cervical spine instability. This controversy remains unresolved. In this report, we describe anesthesia for a patient with advanced rheumatoid arthritis in whom LMA insertion was impossible. The reason was thought to be the acute angle between the oral and the pharyngeal axes at the back of the tongue. We investigated the correlation between the angle and difficulty of LMA insertion in an attempt to resolve the controversy.