To the Editor:
The LMA Supreme ™ (Laryngeal Mask Company Limited, Le Rocher, Victoria, Mahe, Seychelles) is the first and only single-use laryngeal mask airway (LMA) with gastric access that combines the desirable features of the LMA-Fastrack ™, LMA-Proseal ™, and LMA-Unique ™.1Until now, no adverse effects have been reported related to its use. We report on a 64-yr-old woman (height, 174 cm; weight, 68 kg) scheduled for breast-conserving surgery for breast cancer. After general anesthesia induction with boluses (2 mg/kg of propofol and 1 μg/kg of remifentanil over 30 s), the patient's lungs were ventilated using a facemask for 2 min. A size 4 LMA-Supreme ™ was chosen according to the manufacturer's guidelines and inserted at the first attempt using a one-handed rotational technique with the patient's head in the semisniffing position. The LMA-Supreme ™ cuff was inflated to and maintained at 60 cm H2O. No air leaks were detected. The LMA-Supreme ™ was secured to the patient's face with adhesive tape, according to manufacturer's instructions. Anesthesia was maintained with infusion of propofol (6 mg · kg−1· min−1) and remifentanil (0.2 μg · kg−1· min−1). The lungs were ventilated with an oxygen–air mixture (fraction of inspired oxygen 0.3). A tidal volume of 600 ml was administered through volume-controlled ventilation with a peak airway pressure of 14 cm H2O. Ten minutes after insertion of the LMA-Supreme ™, peak airway pressure increased from 14 to 18 cm H2O and a 20% leakage occurred. The anesthesiologist repositioned the LMA-Supreme ™ by gently moving it further inward into the pharynx until the air leaks ceased and refixed the device in the new position with the fixation tab (FT) in contact with the patient's upper lip. The surgical procedure lasted 80 min. The patient was then awoken and LMA-Supreme ™ removed. The patient complained of a slightly swollen upper lip with sensory loss to the midline that was confirmed by examination. Neurologic findings corresponded to a pressure damage in the infraorbital nerve, a branch of the maxillary nerve (second branch of the trigeminal nerve), which innervates the upper lip. The complication started to improve after a week and regressed completely after 14 days.
LMA-Supreme ™ is a new ventilatory device with innovative constructive features such as the FT that, although generally favorable, requires special attention. For example, the FT is a rectangular structure molded onto the manifold at right angles and it projects over the patient's upper lip. The FT was not present in any previous model of LMA masks and has been designed to facilitate insertion and fixation of the LMA-Supreme ™.2According to the manufacturer's instructions, the distance from FT to the upper lip should be between 0.5 and 2 cm. If the tab is flush against the upper lip, a larger size LMA-Supreme ™ should be used.2The FT to lip distance is easy to keep at the beginning of anesthesia but it may be not so during anesthesia. The tape securing the mask is passed across the FT and may make it hard to visualize the FT-to-lip distance especially where the FT connects with the bite block. Also, cuff pressure may change during anesthesia and alter FT-to-lip distance.
Repositioning or replacing a laryngeal mask with a different sized mask or with an endotracheal tube is required in some patients because of mask malfunctioning. Repositioning the mask is the first and most often successful approach for air leaks. In a recent study, 13 cases of air leaks occurred out of 100 insertion of LMA-Supreme ™ and all were taken care of with repositioning.1Replacing the mask is easy after induction of anesthesia but may involve risk of airway loss and pulmonary aspiration when performed during surgery.3,4Although recommended in the manufacturers' instruction, when the FT-to-lip distance was less than 0.5 cm, we did not find any case of mask replacement in the growing literature on LMA-Supreme ™. Our practical experience has shown us that LMA-Supreme ™ is an excellent device. In this case, however, the reducing FT-to-lip distance went undernoticed. The case taught us that the performance of LMA-Supreme ™ has to be closely monitored throughout anesthesia and also for FT-to-lip distance.
*Istituto di Anestesia e Terapia Intensiva, Università di Padova, Padova, Italy. firstname.lastname@example.org