Identifying the Cricothyroid Membrane in Non-Obese Subjects with Normal Neck Anatomy:A Comparison of Palpation, Laryngeal Handshake and Ultrasound after Formal Training

BACKGROUND INFORMATION When patients undergo general anaesthesia, it is vital that the anaesthetist is able to oxygenate them by providing ventilation through their airway. Rarely, this is not possible, and the final step in this process of managing this clinical emergency is to gain access to the trachea via the front of the neck, via the cricothyroid membrane (CTM). We compared the accuracy, confidence and speed of techniques to identify the CTM, and whether skin markings remained over the CTM after moving the neck. PARTICIPANT CHARACTERISTICS Operators: three anaesthetists (mean age 33 years, range 30-34 years) and three medical students (mean age 21 years, range 20 - 23 years). Simulated Patients (SPs): 11 female SPs, mean age 70 years (range 53 - 81 years) with mean BMI 25.6 kg/m2 (range 20 - 32 kg/m2). KEY RESULTS The highest accuracy (84.9%) was achieved by anaesthetists using ultrasound, but there was no statistically significant difference in accuracy of any method overall. Operators were significantly more confident using ultrasound compared to palpation, but took significantly longer. Experienced operators were significantly quicker and more confident, but no more accurate. Skin markings remained over the CTM after time and changing position of the neck when. LIMITATIONS No SPs assessed had any known pathology of the front of the neck and all were of near normal BMI (mean 25.57 kg/m2), so care must be taken when extrapolating these results to other patients.