J Spec Oper Med. 2019 Fall;19(3):71-75.

# A Comparison of the Laryngeal Handshake Method Versus the Traditional Index Finger Palpation Method in Identifying the Cricothyroid Membrane, When Performed by Combat Medic Trainees.

Moore A, Aden JK 3rd, Curtis R, Umar M.

BACKGROUND: The laryngeal handshake method (LHM) may be a reliable standardized method to quickly and accurately identify the cricothyroid membrane (CTM) when performing an emergency surgical airway (ESA). However, there is currently minimal available literature evaluating the method. Furthermore, no previous CTM localization studies have focused on success rates of military prehospital providers. This study was conducted with the goal of answering the question: Which method is superior, the LHM or the traditional method (TM), for identifying anatomical landmarks in a timely manner when performed by US Army combat medic trainees?

METHODS: This prospective randomized crossover study was conducted at Ft Sam Houston, TX, in September 2018. Two Army medic trainees with similar body habitus volunteered as subjects, and the upper and lower borders and midline of their CTMs were identified by ultrasound (US). The participants were also recruited from the medic trainee population. After receiving initial training on the LHM and refresher training on the TM, participants were asked to localize the CTMs of each subject with one method per subject. Success was defined as a marking within the borders and 5mm of midline within 2 minutes.

RESULTS: Thirty-two combat medic trainees participated; 78% (n = 25) successfully localized the CTM using the TM versus 41% (n = 13) using the LHM (p = .002).

CONCLUSION: Findings of this study support that at present the TM is a superior method for successful localization of the CTM when performed by Army combat medic trainees.