Use of a mechanical simulator for training in applying cricoid pressure

Using an airway management training model, we have assessed anaesthesia personnel in their use of correct cricoid force and ability to retain this skill after a short training programme. A perspex device, working on a hydraulic principle, was used to measure cricoid pressure when applied to the model. After initial assessment at two levels of cricoid force (20 and 40 N), participants undertook additional training on 3 consecutive days. Thereafter, available participants underwent reassessment at 14-21 days. Forty-nine anaesthetic assistants and anaesthetists underwent initial assessment and 18 completed the full training and reassessment. Untrained, the majority (63%) of participants applied inadequate cricoid force with a wide variation (mean 16.8 (SD 9.3) (range 4.5-43.0) at 20 N and 32.9 (13.3) (14.9-74) at 40 N). After a single training session there was a marked improvement in application of cricoid force. Two additional training sessions did not provide further improvement. After 14-21 days the ability of participants to apply correct cricoid force was retained by 72% of subjects. Those who applied inadequate cricoid force initially were more likely to do so even after training. Most subjects applied too great a cricoid force in the first 5 s of application followed by a progressive loss of force during the next 20 s. This trend improved after training. We conclude that the majority of untrained personnel apply inadequate cricoid force, placing patients at risk of aspiration of gastric contents. While a simple training programme improved application of cricoid force, retained for up to 3 weeks, there was often a substantial decrease in the force applied to the cricoid during a single application, even after training.