Unilateral Hypoglossal Nerve Palsy after the Use of a Novel Supraglottic Airway Device

Abstract

Background: The LMA® Protector™ Airway is a new supraglottic airway device with Cuff Pilot™ Technology that enables visual monitoring of intra-cuff pressure, to reduce the risk of complications from an overinflated device. Case: We present a case of unilateral hypoglossal nerve injury after its use. In our knowledge, this is the first reported case of hypoglossal nerve injury after LMA® Protector™ use. Learning Points: Hypoglossal nerve injury is a rare but distressing complication of LMA use. The greater horn of the hyoid bone is a potential site of injury, as the cuff of the LMA may compress the nerve against bone. In our patient, possible contributing factors included cuff overinflation with/without failure of the Cuff Pilot™ technology, inappropriate sizing and placement of an unfamiliar device. Fortuitously, injury is often neuropraxia with complete recovery in 6 months following conservative management. Consideration should be given to down-sizing the device for Asian patients who tend to have smaller jaws for their weight range. We caution that whilst the green zone of the Cuff Pilot™ corresponds to 40 - 60 cm H2O cuff pressure, it may be more than the “just-seal” pressure required and the cuff may still be overinflated relative to the size of the patient’s airway.