RESISTANCE TO CONSTANT AIR FLOW IMPOSED BY THE STANDARD LARYNGEAL MASK, THE REINFORCED LARYNGEAL MASK AND RAE TRACHEAL TUBES

The reinforced laryngeal mask airway (RLMA) has been introduced recently for head and neck surgery. Its resistance to constant air flow has been measured and compared with that of the standard laryngeal mask airway (LMA). The RLMA resistance has also been compared with that imposed by the standard oral Ring-Adair-Elwyn (RAE) tube of a corresponding size for a given patient. The resistance to gas flow of the new RLMA was approximately three to five times that of the LMA at two flow rates (0.5 and 7.0 litre s -1 ). The resistance of the RLMA 4 was intermediate between that of RAE tubes sizes 8 and 9 mm, and that of RLMA 2 intermediate between that of RAE tubes sizes 5 and 6 mm. ( Br. J. Anaesth. 1993; 71: 594–596 )