Objective: Debates continue about the cricoid pressure, which has been used for many years to prevent gastric aspiration during intubation. Using ultrasound, the effects of this maneuver and alternatives like paralaryngeal pressure are revealed. The aim of this observational study was to determine the effect of paralaryngeal pressure with an ultrasound probe on the esophageal diameter in patients with different body mass indexes and neck circumferences.
Methods: After measuring the neck circumference at the level of the cricoid cartilage, the esophagus was visualized by ultrasonography. Compression was applied medially at a 45° angle toward the vertebral column by the ultrasound probe and esophageal anteroposterior outer diameters were measured. Correlations between body mass index, neck circumference, esophageal diameter, and esophageal diameter change ratio were evaluated with Pearson's r value.
Results: One hundred ten volunteers (52 women and 58 men) with mean age 33.7 ± 8.02 years and mean body mass index 25.6 ± 4.65 kg m-2 were recruited. The esophagus was located 78.18% partially to the left, 4.54% completely to the left, 1.81% to the right of the cricoid ring. In 15.45%, esophagus could not be displayed. The mean diameter of the esophagus was 7.6 ± 1.1 mm before pressure and 5.6 ± 0.09 mm after pressure (P < .001). There was no significant correlation between diameter change percentage and body mass index (r=-0.22; P > .05). However, weak correlation was found between diameter change percentage and neck circumference (r=-0.33; P=.016).
Conclusions: Paralaryngeal pressure with an ultrasound probe has the potential to occlude the esophagus and may be effective in all patient groups.