Abstract
Cricoid pressure is used to reduce the risk of aspiration during rapid
sequence induction. The recommended force applied to the cricoid is
10-20 newtons (N; 1.020-1.040 kg) on awake patients and 30-40N
(3.060-4.080 kg) on anaesthetised patients. However clinically, it is
difficult to estimate the required force. We assessed the effectiveness
of 3 recommended teaching methods on the ability to apply the correct
force using an airway model that simulated “awake” and
“anaesthetised” patients. Thirty nurses and doctors from two hospitals
and with clinical experience applying cricoid pressure were included.
Measurements of baseline force for “awake” and “anaesthetised”
patients were obtained from all participants using measuring scales.
Participants were blinded to the force applied. Participants were taught
one of three different techniques: biofeedback, nose and syringe.
Post-teaching, blinded force measurements were repeated. Data analysis
was performed using a linear mixed model and marginal prediction models
of applied force reported. For “awake” patients, nose method forces
were within the recommended range (mean 14.6N, 95%CI 9.7-19.4). The
biofeedback method led to predicted forces at the upper limit of
recommended (21.6N, 95%CI 16.7-26.4) and the syringe method forces were
greater than recommended (29.0N, 95%CI 23.9-34.0). For
“anaesthetised” patients, nose method forces were less than
recommended (26.3N, 95%CI 21.6-31.1), the biofeedback method led to
predicted forces within range (33.4N, 28.4-38.3) and syringe method
forces were above those recommended (40.8N, 95%CI 35.8-45.8). The
biofeedback technique is the most effective method for teaching the
application of recommended cricoid pressure force for both awake and
anaesthetised patients.