LAUSR

This study aimed to identify the risk factors for difficult intubation in thyroid patients [1]. As the authors Liu et al. noted, a difficult intubation is a result of a combination of many factors. The patient’s specific risk factors, techniques, equipment, experience of the anesthetist, and concomitant factors create its complexity. For this reason, it would be a weak determinative indicator to use only the American Society of Anesthesiologists’ (ASA) description for difficult intubations in this study: ‘‘Tracheal intubation requires multiple attempts, in the presence or absence of tracheal pathology’’ [2]. We preferred to use the modified intubation difficulty scale (MIDS), which includes multiple parameters related to the operator, the procedure used, and other variables to describe its difficulty [3]. In our manuscript, the number of additional attempts, the Cormack– Lehane scale, the pressure applied during laryngoscopy, extra laryngeal pressure, and difficulty passing the tube through the larynx were all evaluated to define intubation difficulty with the MIDS scoring system. The number of intubation attempts, which is also recommended by the ASA for difficult cases, has already been used as a parameter in our study. Patients classified according to the MIDS data were compared with additional difficult intubation criteria. There is not a test or assessment method that has high sensitivity and specificity to define a difficult intubation in its own right [4]. In our study, we used certain tests (thyromental distance, sternomental distance, interincisor gap, mandibular protrusion, and the Cormack–Lehane score) that have been already used in routine anesthesia practice to determine risk factors [2]. Along with these parameters, the study included neck circumference, presence of goiter, thyroid weight, presence of malignancy, with radiological and clinical compression findings as potential risks to assess any intubation within the thyroid group. All these data obtained from the patients with multiple tests and measurements were evaluated to predict the possible difficult intubation in thyroid patients. In our study, laryngoscopy was performed by the same anesthesiologist with a Macintosh-type laryngoscope to preclude induced bias in the practitioner, which was carefully emphasized in Materials and Methods section of the manuscript. Cormack–Lehane scores obtained from a Macintosh laryngoscope were also used in statistical comparisons; the anesthetist, the materials used, and the position of the patient were standardized in this study. The main purpose of this study was to determine possible risk factors leading to complicated intubation in thyroid patients. We wanted to evaluate the factors which are important for identifying difficult intubation in thyroid patients both in preoperative measurements and factors specific to these type of patients. As such, it is appropriate to use the expression ‘‘difficult intubation’’ in the title of this study.