Anaesthesia. 2018 Oct;73(10):1235-1243

# Evaluation of a novel criocthyroidotomy introducer in a simulated obese porcine model: a radomised crossover comparison with scalpel cricothyroidotomy.

Yeow C, Greaney L, Foy C, King W, Patel B

The Difficult Airway Society 2015 guidelines for management of unanticipated difficulties in tracheal intubation in adults have generated much discussion regarding Plan D: emergency front-of-neck access with a scalpel-bougie cricothyroidotomy technique. There is concern that this technique may not provide an adequate pathway for the bougie and subsequently the tracheal tube, especially in obese patients with deeper airway structures. This could lead to the formation of a false passage, trauma and failure. A novel cricothyroidotomy introducer, 8 mm wide and 170 mm long, with a sharp leading edge and guiding channel to pass a bougie into the trachea, has been designed to complement the scalpel cricothyroidotomy technique. A comparison study of the use of this novel introducer with the scalpel technique in a simulated obese porcine laryngeal model demonstrated shorter insertion times (median (IQR [range]) 85 (65-123 [48-224]) s vs. 84 (72-184 [46-377]) s, p = 0.030). All 26 (100%) participants successfully performed cricothyroidotomy in the introducer group, whereas only 24 (92%) participants were successful in the scalpel group. The introducer group required fewer attempts to access the trachea compared with the scalpel group (p = 0.046). False passages occurred eight (31%) times in the introducer group compared with 17 (65%) times in the scalpel group (p = 0.022). There were no statistical differences in tracheal trauma (p = 0.490), ease of use (p = 0.220) and device preference (p = 0.240). This novel cricothyroidotomy introducer has shown promising results in securing the airway in an emergency front-of-neck access situation. With robust training, this introducer could potentially be complementary to the scalpel-bougie cricothyroidotomy technique.