Real-time vs. static ultrasound-guided needle cricothyroidotomy: a randomized crossover simulation trial.

Cricothyroidotomy is a key technique for securing airways when tracheal intubation and oxygenation are difficult to achieve. In recent years, it has become clear that ultrasonography is more accurate than palpation for identifying the cricothyroid membrane. However, it is unclear how ultrasound should be administered. We investigated whether real-time or static ultrasound techniques were more useful for needle cricothyrotomy in patients with simulated anatomical abnormalities of the neck. Three cervical simulators with anatomical abnormalities were created. After education and hands-on training in needle cricothyroidotomy, 48 participants (27 junior residents, 12 anesthesia residents, and nine anesthesiologists) performed needle cricothyroidotomy using either a real-time or static ultrasound technique (crossover study). Fisher's exact test was used to assess the success rate and accuracy of the puncture (p < 0.05 was considered statistically significant). The success rate of cricothyrotomy puncture was significantly higher with the real-time ultrasound technique than with the static ultrasound technique. The real-time ultrasound technique led to significantly higher puncture accuracy and shorter procedure time than the static ultrasound technique. Needle cricothyroidotomy using real-time ultrasonography may be more useful than that using static ultrasonography.