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Intubation via a laryngeal mask airway with an Aintree catheter – not all laryngeal masks are the same

2007; Wiley; Volume: 62; Issue: 9 Linguagem: Inglês

10.1111/j.1365-2044.2007.05235.x

1365-2044

K. B. Greenland, H K Tan, Mark J. Edwards,

Respiratory Support and Mechanisms

We would like to congratulate Blair and colleagues [1] for their article comparing the LMA Classic™ (cLMA) and LMA Proseal™ (PLMA) laryngeal masks (Intavent Orthofix Ltd, Maidenhead, UK) in combination with the Aintree Intubation Catheter (Cook Critical Care, Bloomington, IN) for the intubation of manikins. We have used both types of laryngeal masks with the Aintree Intubation Catheter for difficult airway management in anaesthetised patients based on Higgs's case series [2]. We have extended our work to both the 'Unique' laryngeal mask airway (Intavent Orthofix Ltd) and the Laryngeal Mask Airway Supreme™ (The Laryngeal Mask Company, Mahe, Seychelles), which are single-use counterparts of the cLMA and PLMA. Unfortunately, the design of the Supreme differs significantly from PLMA by the addition of 'epiglottic fins' (1, 2) in the bowel of the laryngeal mask. These fins were included in the new design to block the epiglottis entering the opening of the laryngeal mask. Laryngeal Mask Airway Supreme showing the epiglottic fins in the bowel. Proseal LMA without the epiglottic fins. As a flexible fibreoptic bronchoscope and Aintree catheter are inserted into a Supreme, these fins trap the catheter in the sagittal plane, thus impeding its manoeuverability and subsequent insertion through the glottis. However, if the anaesthetist guides the bronchoscope and catheter above the fins so as to avoid this entrapment, then the normal range of movement of the catheter is maintained. Figure 3 shows the direction of the catheter as it exits the Supreme if it is below the fins. In this position the catheter is fixed and cannot be manipulated by the bronchoscope. In contrast, Fig. 4 shows that when the catheter sits above the flanges, it not only exits at a less acute angle from the laryngeal mask airway bowl, but there is also a significant range of movement possible with manipulation. In the latter case, the degree of flexibility of the catheter is similar to that of the PLMA. Direction of Aintree Intubation Catheter when it is below the epiglottic fins. Range of movement of the Aintree intubation catheter when sitting above the epiglottic fins. Unfortunately, due to the transparent nature of the Supreme, we have frequently found directing the bronchoscope above these fins can be difficult and find ourselves trapped underneath them. We would therefore advise caution when using this technique with the Supreme laryngeal mask airway, but certainly endorse the combination of the PLMA and Aintree catheter in difficult airway management.