Under general anesthesia, the rate of failed intubation ranges from 1.5% to 13%, raising concerns among anesthesiologists whose primary goal is successful airway management. In this context, various physical and ultrasonographic measurement techniques have been developed to predict difficult intubation. Ultrasonography is effectively used for estimating tracheal tube size, device placement, diagnosing upper airway pathologies, and guiding percutaneous tracheostomy. In thyroid pathologies, intubation difficulty may increase; however, the impact of goiter remains debatable, as some conditions causing hypothyroidism are reported to lead to thyroid gland atrophy rather than hypertrophy. The study's hypothesis is that an atrophic or fibrotic thyroid isthmus may be associated with difficult laryngoscopy and intubation. Evaluation will be performed using the Cormack-Lehane score (Grade III-IV) and the Intubation Difficulty Scale (IDS \>5). The aim is to determine the relationship between thyroid isthmus thickness and difficult laryngoscopy and intubation during elective intubation in patients receiving hypothyroidism treatment. Preoperatively, patients' demographic and clinical data (age, gender, height, weight, BMI, comorbidities, ASA score, thyroid medication dose, treatment duration, and type of thyroid disease) will be recorded. In the premedication room, after administering 0.01 mg/kg IV midazolam, the distance between the thyroid isthmus and the skin will be measured using a linear ultrasound probe (3-13 Hz) in the supine position with neck hyperextension at the level of the 2nd-3rd tracheal rings; the average of three measurements will be recorded. In the operating room, under noninvasive monitoring and following mask pre-oxygenation, anesthesia induction will be performed using IV 2 mg/kg propofol, 1 µg/kg fentanyl, 1 mg/kg lidocaine, and 0.6 mg/kg rocuronium. Once the TOF reaches zero, an experienced anesthesiologist will intubate using a size 3 Macintosh blade for females and size 4 for males with an appropriate endotracheal tube. The intubation time, defined as the interval from laryngoscope insertion until the first capnography wave is detected, will be recorded along with the Cormack-Lehane and EZS scores and the requirement for video laryngoscopy. In cases of failed intubation, the 2022 ASA Difficult Airway Management Guidelines will be applied.
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Cormack-Lehane score and Intubation Difficulty Scale values of patients whose isthmus thickness is below 3 mm.
Timeframe: From enrollment to the end of treatment at 6 Mounths