The Three-Dimensional Computed Tomography Imaging and Prediction of Unanticipated Difficult Tracheal Intubation

Abstract

In response We appreciate the interest and comments of Dr. Naguib regarding our case report (1). The patient probably received postoperative radiotherapy. However, details of the therapy were not clear because the treatment was done in another hospital 6 yr ago. Dr. Naguib suggested that a combination of clinical and radiologic tests improved prediction of difficult intubation (2). We agree with Dr. Naguib that increasing preoperative tests results in higher prediction rates for difficult intubation. However, despite careful preoperative evaluation, difficulties will not be predicted in some instances. Thus, most importantly, strategies to manage the unanticipated difficult airway should be preformulated and practiced. Dr. Naguib also pointed out that the measurements derived from the 3D-CT images did not improve the predictability of their models (2). Three factors could have been responsible for this result. First, the 3D-CT image is not appropriate for dynamic and qualitative airway assessment because we are unable to estimate the stretching of soft tissue. Therefore, the 3D-CT is useful when airway distortion is evident (3). Second, Dr. Naguib et al. (2) did not mention how they perform the 3D-CT scanning. In our study, to simulate an intubating position, the patient was asked to open his mouth fully and extend his tongue as much as possible. Third, in our study, the patient’s airway was superimposed over translucent images of bones. This image allowed us to evaluate the airway more precisely, including its relationship to surrounding tissue. Noriaki Kanaya MD, PhD Akiyoshi Namiki MD, PhD