Sonographic Assessment of Cricoid Pressure

The study first involves recording a baseline image of the neck anatomy using ultrasound, which is a non-invasive, non-irradiating, non-painful imaging modality. Once the baseline anatomy has been imaged, conventional cricoid pressure will be applied with fingers and/or with the ultrasound probe itself and an image will be recorded. The force applied to the cricoid cartilage will be 30 newtons, as determined by a thin force measurement sensor (Tekscan flexiforce sensor) placed in between the patient's skin and the finger (or ultrasound probe).

Next, left lateral paralaryngeal pressure will be applied at the level of the cricoid cartilage with fingers and/or the ultrasound probe itself, and the image will again be recorded. Left lateral paralaryngeal pressure will be 30 newtons, as determined by a thin force measurement sensor placed in between the patient's skin and the finger (or ultrasound probe).