Caution in performing epidural injections in patients on several antiplatelet drugs.

70 the Editor:-A patient was anesthetized for an orthopedic procedure and a no. 4 laryngeal mask aiway (LMA) was inserted. An air leak around the LMA was observed at approximately 12 cm H,O pressure, causing ventilation to be inadequate. I attempted to alleviate the air leak by repositioning the LMA, changing the cuff inflation volume, and repositioning the patient's head, with no success. Accordingly, I prepared to exchange the LMA with an endotracheal tube when the circiilating nurse placed ii thyroid shield on the patient in preparation for fluoroscopy. The air leak ceased and the case was completed using the LMA. On several subsequent occasions, I have successfully used a thyroid shield to ameliorate an air leak around an LMA. The patient shown in figure 1 is such iin example. The patient had a no. 4 LMA inserted without difficulty, hut despite multiple manipulations of the LMA, LMA cuff, and the patient's head, the LMA had a persistent leak at 10-12 cni H,O. The patient was breathing spontaneously hut entraining room air around the LMA cuff. Placement of a thyroid shield allowed positive pressure ventilation up to 22 cm ti,(>, and the room-air entrainment stopped with spontaneous ventilation. To date, I have had no instances o f failure t o correct an LMA cuff leak and was able to proceed with the anesthetics planned using an LMA. The mechanism for this result seems to he that the thyroid shield forces the soft tissue o f the anterior pharynx against the LMA cuff. LMA cuff pressure is adjusted to maintain an air leak around the LMA o f 20-25 cni H,O to lessen the risk of pharyngeal mucosal ischemia. Fig. 1. Patient with laryngeal mask airway and thyroid shield in place.