Cricothyrotomy is a rare, time sensitive procedure that is more challenging to perform when anatomical landmarks are not easily palpated before the initial incision. There is a paucity of literature describing the optimal technique for cricothyrotomy in patients with impalpable airway structures, such as in morbid obesity. In this study, we used a live sheep model of morbid obesity to compare the effectiveness of two common cricothyrotomy techniques.

We randomly assigned emergency medicine residents to perform one of two cricothyrotomy techniques on a live anesthetized sheep. To simulate the anterior soft tissue neck thickness of an adult with morbid obesity we injected 120 mL of a mixture of autologous blood and saline into the anterior neck of the sheep. The traditional technique (as described in the New England Journal Video titled “Cricothyroidotomy”) used a Shiley tracheostomy tube and no bougie, and the bougie-guided technique used a bougie and a standard endotracheal tube. The primary outcome was the total procedure time; the secondary outcome was first attempt success.

23 residents were included, 11 assigned to the bougie-guided technique and 12 to the traditional technique. After injection of blood and saline, the median depth from skin to cricothyroid membrane was 3.0 cm (IQR 2.5–3.4 cm). The median time for the bougie technique was 118 s (IQR 77–200 s) compared to 183 s (IQR 134–270 s) for the traditional technique (median difference 62 s, 95% CI 10–144 s). Success on the first attempt occurred in 7/11 (64%) in the bougie group and 6/12 (50%) in the traditional technique group.

In this study, which simulated morbid obesity on a living animal model complete with active hemorrhage and time pressure caused by extubation before the procedure, the bougie-guided technique was faster than the traditional technique using a tracheostomy tube without a bougie.