The flexible reinforced laryngeal mask (FLM) is a commonly used anaesthetic airway for oral surgery procedures under general anaesthesia.   With the use of FLMs there is a range of recognized problems including dislodgement, obstruction of ventilation or loss of ventilation. Both authors have observed for many years that airway problems with the use of FLMs during oral surgery have occurred more frequently in patients of Chinese or South East Asian (CSEA) background rather than those of Caucasian background.  We have been unable to find a reference to this ethnic difference in the literature. 

We performed an audit to determine if a difference actually exists in the rate of airway problems between these two groups of patients when laryngeal mask anaesthesia is used in oral surgery.

We prospectively collected data on 298 consecutive oral surgery cases having their procedure under general anesthesia using an FLM.  In all cases the FlexyPlus (Teleflex) flexible reinforced tube laryngeal mask was used. All cases were treated by the same experienced anaesthetist (JB) and the same experienced surgeon (MS). 

In most of our patients who had airway problems the problem with ventilation occurred with positional changes of the mandible. That is, after the surgeon inserted the mouth prop or when pressure was exerted on the mandible. We found an overall (minor and major) airway complication rate of 12.8%. Those of CSEA descent had a major airway complication rate of 15.6% as compared with those of Caucasian descent who had a major complication rate of 1.9%. That is, the CSEA group had about an eight fold increased chance of developing a major airway problem compared with the Caucasian group.

This newly described difference in ethnic subpopulations requires further study to determine the cause and possible solutions.