Cricoid pressure training: how useful are descriptions of force?

Cricoid pressure has been used for over 200 years. During that time, training in the technique has not changed greatly, despite the well-documented potential for complications if performed improperly. Typically, training relies on quantitative or qualitative descriptions such as "firm" pressure, a number of Newtons of force or equivalent force to that causing pain while pressing on the nose. This study tests the value of these descriptive methods in training to apply cricoid pressure. Fifty subjects were asked to apply cricoid pressure after receiving a description of the force required and again after having tested how much finger pressure on the bridge of their nose was required to cause discomfort. Initial force, force at 45 seconds, minimum force, and maximum force was recorded. The results were analysed using the Wilcoxon signed ranks test, which showed no significant difference in performance between the two types of training. One subject maintained pressure in the range of 25 to 35 Newtons for the entire 45 seconds of the first attempt but no subject performed this well on the second attempt. The use of qualitative and quantitative descriptors of the appropriate pressure does not appear useful in the training of the technique of cricoid pressure. Training incorporating force feedback is recommended.