The LMA Supreme and LMA ProSeal

I agree with Eschertzhuber et al. [1] that ease of insertion, positioning and use of the LMA Supreme (The Laryngeal Mask Company Ltd, St Helier, Jersey, UK) are similar to the LMA ProSeal but not the same. Since introduction, the Supreme has quickly caught on as the ProSeal of first choice in our hospital group especially for difficult patients. The new features have made it easier to handle and use than the ProSeal. However the finding that leak and cuff pressure are higher for the ProSeal suggests that it fits more tightly than the Supreme. Cuff pressures do not bear a direct relationship to leak pressures. The materials play a part in the compliance of the device as do the volume and elasticity of the patient’s oropharynx. In my experience the ProSeal has to be sized correctly for the individual patient, positioned carefully and kept in position. If this is done leak pressures above 40 cm H2O can be obtained [2]. That leak pressures are lower in the Supreme may be due to materials: silicone rubber being ideal for moulding, but it could also be due to positioning and subsequent movement of the airway after insertion. The fixed curved tube of the LMA Fastrach provides a great advantage on initial insertion but this curve does both dictate and limit how far the tip of the device can go down the oropharynx. Finally, in some patients, the Supreme tends to emerge or work its way out after insertion. These two factors can account for the lower seal pressures achieved by the Supreme compared to the ProSeal. When it comes to fixation of the device the manufacturer’s instructions 2007 simply say: ‘…lay the adhesive tape transversely across the fixation tab and press both ends of the tape down onto each of the patient’s maxillae….’ [3] In my view, this is not sufficient to keep the Supreme firmly enough applied to the hypopharynx and allows it to re-emerge 1–2 cm during use. I fix the Supreme as securely as I can once it is in position and even advocate the use of a traditional round the neck tube-tie instead of adhesive tape on the lax tissues of the face and cheeks. If the Supreme is held firmly in position seal pressures similar to those of the ProSeal can be achieved.