Dimensional compatibility of currently available equipment for cricothyroidotomy and adult airway anatomy: an in vitro analysis

In the Nick of Time-Emergency Front-of-Neck Airway Access

Emergency front-of-neck access refers to all techniques that deliver oxygen into the airway lumen through the anterior neck structures and encompasses access both through the cricothyroid membrane and the tracheal wall. There has yet to be a universal agreement regarding the preferred technique. A surgical incision is currently the most common approach in prehospital and in-hospital care. This review intends to review and summarize the existing clinical, basic science, and societal guidelines for eFONA.

Determination of the Cricothyroid Membrane Height by Age and Sex and Optimal Tracheal Tube Size

OBJECTIVES

The primary aim of this study was to determine the average cricothyroid membrane (CTM) height in healthy volunteers, and the secondary aim was to determine the hypothetical success rate for emergency cricothyrotomy with a tracheal tube with an 8.0 mm outer diameter.

METHODS

This study included healthy volunteers aged 18 years and older. The participants' clinical characteristics were recorded, and their CTM height was measured using ultrasound, with their necks placed sequentially in the neutral and extension positions. The relationship between the CTM height and sex, age, height, weight, body mass index, and sternomental distance was evaluated using linear regression analysis. An equation that could estimate the height of the CTM was obtained with the parameters found significant in this analysis.

RESULTS

Of the 340 participants, 208 (61.2%) were male. The mean (SD) height of the CTM in the extension position was 9.60 (1.54) mm, and it was significantly shorter in the women than in the men (8.72 [1.19] mm vs. 10.16 [1.48] mm, p < 0.001). Among the participants of short stature, the CTM was significantly shorter, regardless of sex. The hypothetical success rate for emergency cricothyrotomy was 93.3% for the males and 73.5% for the females. The equation for estimating the height of the CTM in the extension position was determined as -4.36 + 5.27 × height (m) + 0.32 × sternomental distance (cm).

CONCLUSIONS

Since the CTM height may differ according to age, sex, and height, cricothyrotomy sets should be available in various outer diameters.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:1825-1830, 2024.