Athanassoglou V, et al. - Given that the knowledge of possible depth to the airway prior to emergency cricothyroidotomy may improve success in cases where it cannot be measured, researchers used ultrasound to measure the depth to the airway at the cricothyroid membrane in a large group of adult patients (n = 352) who presented for a large variety of surgical operations and were investigated in this prospective, observational analysis. They excluded patients under 18 years; pregnant; critically ill; had a history of neck surgery. In statistical analysis, an equation was generated for the prediction of the upper 95% CI of depth to the airway from the patient's weight: Depth to the airway lumen in mm = (0.13 × weight in kg) + 0.86. These results could enable clinicians to predict the depth to the airway in cases where it is not possible to obtain ultrasound measurements prior to emergency cricothyroidotomy. If the upper 95% CI were used as the depth of incision, it would enter the airway in 39 out of 40 patients of that weight, without injury to posterior structures in those with a shallower airway.