When people are putting pressure on me, I just completely ignore it. – Zayn Malik
The aim of the study was to investigate the functional impact on cricoid and paralaryngeal pressure on the outer anteroposterior diameter of the upper oesophagus at the cricoid cartilage level.
The study was a prospective, observational study of 34 healthy volunteers, all of whom were conscious. Doctors used ultrasound to measure the antero-posterior diameter of the upper oesophagus. Each volunteer had three measurements taken; a neutral measurement (no pressure), one with cricoid pressure and one with paralaryngeal pressure.
Cricoid pressure was found not to be effective at compressing the upper oesophagus in conscious, healthy volunteers (mean diameter of the oesophagus 0.79cm, SD 0.13) compared to no pressure (mean 0.77cm, SD 0.11) p-value 0.504. Paralaryngeal pressure was more effective at compressing the oesophagus in these volunteers (mean 0.68, SD 0.12) compared to neutral (p-value <0.001) and cricoid pressure (p-value <0.001).
Although these are statistically significant results, the clinical significance is questionable as there was a difference of less than a millimetre in the oesophageal diameter. There were many limitations to this study, mainly that these volunteers were conscious and that the study was small.
This study is unlikely to change our practice and further studies would need to be carried out in anaesthetised patients to establish the use of paralaryngeal pressure and its effect on oesophageal diameter and laryngoscopy.
Summary by Dr Tejal Dave