Dr. Sellick's Procedure To The Cricoid Pressure

Cricoid pressure is a procedure that is utilized on induction to prevent the regurgitation of stomach contents, most notably into the air passages. The technique of occluding the esophagus by applying pressure to the cricoid was first introduced in the 1960’s by Dr. Sellick. In Dr. Sellick’s technique the patient lies supine with their head and neck fully extended and upon induction an assistant applies steady firm backward pressure to the cricoid cartilage. By applying this backward pressure the patient’s esophagus is temporarily occluded between the cartilage and the cervical vertebral bodies (Sellick). Dr. Sellick also adds an additional benefit to the procedure, which is that it will also prevent inflating the stomach during positive
Cricoid pressure is now widely accepted as a “minimum standard of care” (Ellis, 654) making it almost unethical to preform randomized tests on living patients. In Dr. Sellick’s original article he tested his hypothesis by only attempting his technique on a rather small number of patients and reporting his observations. This poses a problem for some, because it was indoctrinated into practice without through scientific scrutiny. Because it is a minimum standard of care testing its effectiveness must be investigated through a combination of tests on randomized patients and prospective studies. Some of the most notable arguments against the procedure is that it may not effectively occlude the esophagus (Bhatia), its application may obscure Laryngeal view and make tracheal intubation more difficult (Ellis), and most notably the lack of consistency of its application (Priebe). Dr. Sellick’s article utilized the assumption that everyone has their trachea directly superior to the esophagus which is directly superior to the cervical spine. Through the years however there has been observations utilizing CT scans that demonstrated that during cricoid pressure there was a lateral displacement of the esophagus. Also that only one degree of
With this much displacement off of the esophagus with such a minor movement it can be believed that true occlusion of the esophagus isn’t achieved on a consistent basis. The utilization of cricoid pressure can also obscure the view of direct laryngoscopy. Based on several randomized and prospective studies there were varying results but one study documented up to 29% of cases having a deterioration of view with the implementation of cricoid pressure (Ellis). The most problematic issue with cricoid pressure is that isn’t utilized consistently, from time of implementation to the force that the assistant applies to the cricoid. There is a recommendation that 30 - 40 N of force be applied to the cricoid while the patient is asleep and in one study there was a variability of 2 – 80 N of force applied by assistants (Priebe). With this amount of variability it is hard to point to prospective studies as a definitive source of reliable information. It’s not all bad news for Dr. Sellick’s procedure though. It was observed that in even if the cricoid moved laterally that the origin of the esophagus was inferior to the cricoid and therefore it was still effective at occluding the esophagus (Bhatia). There have been