The cricoid pressure applied should approximately have following pressure-

Cricoid pressure describes the backward displacement of the complete cailaginous cricoid ring against the cervical veebrae to occlude the hypopharynx. The technique usually involves the application of a 10 N force before induction; increasing this force to 30 N on loss of consciousness. Thiy Newtons are considered enough to maintain a barrier pressure, but minimize airway obstruction or distoion. It should be removed immediately if active vomiting occurs as there is a risk of oesophageal rupture.