To the Editor:

I would like to thank Wang et al. [1] for their interest in our study comparing the fiberscope and the ultrasound guided techniques for tracheal intubation in patients with cervical spine immobilization. Actually, in the technique described in the study, the rigid neck collar was removed before tracheal intubation to shape the tracheal tube mounted over the stylet according to the previous lateral view X-ray taken in the neutral position. However, some types of cervical neck collars are available having a front window that allow ultrasound examination of the airway.

I agree with Wang et al. [1] that the experience in ultrasound-guided tracheal intubation is critical for its success. The operator in the ultrasound group has been stated to have 7 years of experience in the application of ultrasound in the airway and the intensive care including confirmation of tracheal intubation. The operator also observed the performance of the technique in 20 cases before the beginning of the study; however, they were not belonging to the population of the present study. A number of our staff members have been now well trained with technique and a large study is now being processed on a wide variety of patients.