To the Editor:-Stylets are used to shape pediatric endotracheal tubes (ETTs) to facilitate intubation of the trachea. We report an incident in which there was shearing of the stylet's plastic coating, which led to intraluminal obstruction of the ETT.

General anesthesia was induced in a 1-month-old infant scheduled for bilateral inguinal hernia repair, and the trachea was intubated easily with a 3.0-mm ID non-cuffed ETT (Mallinckrodt, Argyle, NY) with the aid of a 6-French plastic-coated stylet (Portex, Keene, NH). The stylet was removed with difficulty, and it was immediately noted that the plastic coating over the distal part of the stylet was missing. The ETT was immediately removed, and inspection of the removed ETT showed the sheared plastic coating in the distal portion of the tube at the point where it had been shaped to assist in the intubation. The patient was ventilated easily with a face mask, followed by intubation without the aid of the stylet, and the surgical procedure was performed without further incident.

A similar incident involving a 2.5-mm ETT was reported previously, and it was suggested that plastic ETT connectors would obviate the shearing problem. [1]Our incident occurred with a 3-mm ETT, despite the use of a plastic ETT connector. The point of maximum stress and shearing was where the tube was shaped, not at the ETT connector.

If the use of a stylet is necessary, we recommend that the plastic covering of the stylet be removed, the tip of the metal stylet be seated completely inside the ETT to prevent damage to the airway, and that the stylet be bent at the proximal rim of the ETT connector to prevent migration of the stylet distally. If the plastic covered stylet is used, we suggest that the stylet be inspected for its integrity immediately after its withdrawal and that no attempt be made to ventilate through the ETT if shearing has occurred to avoid displacement of the foreign body into the lower airway.

Mukul Bhargava, M.D.

Assistant Professor of Clinical Anesthesiology

Surya N.M. Pothula, M.D.

Assistant Professor of Clinical Anesthesiology

Suhasini Joshi, M.D.

Assistant Professor of Clinical Anesthesiology; New York Medical College; Valhalla, New York 10595

(Accepted for publication October 14, 1997.)

Cook WP: Obstruction of an endotracheal tube by the plastic coating sheared from a stylet. Anesthesiology; 1985; 62:803-4.