Sellick’s maneuver, the application of pressure to a patient’s cricoid cartilage during endotracheal intubation, is supposed to prevent aspiration. The procedure was named after British anesthetist Brian A. Sellick, following an article in the prestigious British medical journal The Lancet. (Sellick) In a series of cadaver experiments, the cadavers’ stomachs were filled with water and cricoid pressure was applied. Then the cadavers were placed into a steep Trendelenburg position.
Sellick found that cricoid pressure, when applied, did not cause regurgitation of fluid into the pharynx. Thus, we in the medical community assumed it worked. In fact, during residency in the late 1980s, I was taught that it would stop regurgitation pressures up to 100 cm/H2O. It became an integral part of rapid sequence induction - especially when dealing with a trauma patient who invariably had just ingested a pepperoni pizza and several liters of beer. But does it really work?
Apparently not — at least not as well as we once thought.
Several researchers have subsequently looked at Sellick’s maneuver and come to the conclusion that it probably does little good and, in fact, can sometimes obscure the view of the operator. In 1983, in a study to determine how much pressure is routinely applied during Sellick’s maneuver, researchers found that while over 78 percent of anesthetists surveyed routinely used the maneuver, 70 percent had experienced a problem with its application. Interestingly, the average force applied was 44.6 N while 47 percent of anesthetists failed to reach a force of 44 N. This indicated that the applied pressure varied greatly. (Howells)
KG Allman found that application of cricoid pressure, even by experienced anesthetists, caused some degree of airway obstruction and, in some cases, caused complete airway obstruction. (Allman) Other researchers reported a case of cricoid cartilage fracture following cricoid pressure during RSI for status asthmaticus. (Heath) British researchers, in 2005, performed a systematic review of the literature regarding cricoid pressure/Sellick’s maneuver and wrote, “There is little evidence to support the widely held belief that the application of cricoid pressure reduces the incidence of aspiration during a rapid sequence intubation.” (Butler)
Australian researchers completed a detailed review of the procedure in last month’s issue of Annals of Emergency Medicine. They concluded:
“Cricoid pressure entered medical practice on a limited evidence base but with common sense supporting its use. Given that the risks of cricoid pressure worsening laryngeal view and reducing airway patency have been well described, we recommend that the removal of cricoid pressure be an immediate consideration if there is any difficulty either in intubating or ventilating the ED patient.” (Ellis)
In summary, the scientific literature is telling us that we need educated paramedics who can apply critical thinking to problems encountered. Sellick’s maneuver (cricoid pressure) is possibly helpful in some patients and not so in others. Likewise, it may be harmful in some patients and not so in others. It is simply another tool in your airway armamentarium. If it helps, use it. If not, don’t. Forcing students to use cricoid pressure as part of some skills test will emphasize that the procedure should be used every time. Like many things in EMS, Sellick’s maneuver is not the panacea we once thought. It is simply another possible tool to use — nothing more, nothing less.
References
- Sellick BA. Cricoid pressure to control regurgitation of stomach contents during induction of anaesthesia: preliminary communication. The Lancet. 1961;2 404-406
- Howells TH, Chamney AR, Wraight WJ, Simmons RS. The application of cricoid pressure. An assessment and survey of its practice. Anaesthesia. 1983;38457-60
- Allman KG. The effect of cricoid pressure application on airway patency. Journal of Clinical Anaesthesia. 1995;7:197-199
- Heath KJ, Palmer M, Fletcher SJ. Facture of the cricoid cartilage after Sellick’s maneuver. British Journal of Anesthesia. 1996;76:877-878
- Butler J, Sen A. Best evidence topic report. Cricoid pressure in emergency rapid sequence intubation. Emergency Medicine Journal. 2005;22:815-816
- Ellis DY, Harris T, Zideman D. Cricoid pressure in emergency department rapid sequence tracheal intubations: A risk-benefit analysis. Annals of Emergency Medicine. 2007;50:653-665
