To the Editor:-Shearing of the plastic sheath of the stylet leading to endotracheal tube obstruction has been reported with smaller tubes. [1]It has been suggested that this happens because of the tight-fitting stylet with a pliable coating and a firm grasp of the endotracheal tube over the stylet. [2]Recently, we also experienced a similar incident with a 6.0-mm inner diameter Carlen's double-lumen tube (DLT)(Portex, Kent, England), which has a stylet provided by the manufacturers.

A 38-yr-old man presented for removal of a hydatid cyst of the left lung during general anesthesia. A 6.0-mm Carlen's DLT was passed into the trachea easily with the aid of stylet provided with the tube. At removal of the stylet, it was noticed that the plastic coating over the distal part of the stylet was missing. The DLT was immediately removed. Fortunately the sheared part of the plastic coating was found stuck in the tube. The patient was ventilated with the face mask and was reintubated with the help of another stylet after lubricating it with sterile water-soluble jelly.

Shearing of the plastic coating of a stylet usually occurs at the point where it is angulated to assist in the intubation. [3]This also happened in our patient. Some force is bound to be exerted at this point during removal of stylet because of the contour of the airway and the tube. The more angulation produced, the greater will be this shearing force.

This case shows that shearing can occur even with larger tubes, and one should always inspect the stylet after withdrawal for integrity of the plastic coating.

Prabhat K. Sinha, M.D.

Prakash K. Dubey, M.D.

Department of Anaesthesiology and Critical Care Medicine;

Sanjay Gandhi Postgraduate Institute of Medical Sciences; Lucknow, India

(Accepted for publication August 31, 1998.)

Rabb MF, Larson SM, Greger JR: An unusual cause of partial ETT obstruction (letter). Anesthesiology 1998; 88:548
Cook W, Schultetus R: Obstruction of an endotracheal tube by the plastic coating sheared from a stylet. Anesthesiology 1985; 62:803-5
Bhargava M, Pothula SNM, Joshi S: The obstruction of an endotracheal tube by the plastic coating sheared from a stylet: A revisit. Anesthesiology 1998; 88:548-9