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