The Comparison of Ultrasound Guided Cricothyroid Membrane Identification Method and Anatomical Landmark Palpation Cricothyroid Membrane Identification Method in Intubated Patients

ABSTRACT

PURPOSE: Cricothyroidotomy had a high failure rate. Ultrasound-guided cricothyroid membrane (CTM) identification may be more accurate and easier than anatomical landmark palpation. The purpose of this study was to compare the accuracy of ultrasound-guided CTM identification method (ultrasound method) and anatomical landmark palpation CTM identification method (palpation method) in patients who were intubated in an emergency medical center. METHODS: Using fluorescent invisible ink, the emergency physician was asked to mark the center of the CTM with the patient by palpation method. After 5 minutes, the participant found the CTM using the ultrasound method and drew a cross with a blue pen. An emergency medicine specialist or senior resident identified the actual center of the CTM with ultrasound and drew a cross with a black pen. The distance between the actual and estimated center of the CTM was measured. Participants measured the ease of use of each method using a 0~10 visual analog scale (VAS). RESULTS: Nineteen patients were enrolled and 38 tests were performed. Both first and second year emergency medicine residents showed that identifying the CTM was more difficult in cases of using the palpation method compared with the ultrasound method. VAS score was 3.0 (1.0-5.0) and 4.0 (2.0-8.0), respectively (p=0.006). Using the ultrasound method and another method, the horizontal length differences were 1.0 mm (IQR 0-2.0) vs. 2 mm (IQR 1.0-3.0) (p<0.001) and the vertical length differences were 1.5 mm (IQR 0-2.0) vs. 3.0 mm (IQR 1.0-9.3), respectively (p<0.001). CONCLUSION: Using the ultrasound method is an easier and more accurate way to find the center of the CTM compared with the palpation method in patients who were intubated in an emergency medical center.