Perioperative Pulmonary Aspiration: Comment

The closed claims analysis of cases of pulmonary aspiration of gastric content by Warner et al.¹  includes important information regarding the impact of the administration of cricoid pressure. In the 49 claims that included endotracheal intubation, cricoid pressure was applied in 22 (45%) and not applied in 19 (39%). In other words, in this cohort pulmonary aspiration was reported more often during than in the absence of applied cricoid pressure. This finding reemphasizes the lack of scientific evidence for a protective effect of cricoid pressure application.^2–4  The authors explicitly acknowledge this fact. Therefore, the onsite anesthesiologist reviewers’ judgment that lack of use of cricoid pressure contributed to aspirations in 15 claims is unjustified.

Administration of cricoid pressure has been documented to be associated with numerous adverse effects, including provocation of gagging and vomiting when applied early during induction of anesthesia⁵ ; worsening of laryngoscopic and intubating conditions^6–8 ; a decrease in lower esophageal sphincter tone^9,10 ; highly variable location, direction, and degree of applied force¹¹ ; and increased physical and cognitive workload for the practitioners.¹²  All of these factors may facilitate gastric regurgitation and subsequent pulmonary aspiration. It could thus be reasonably argued that use of cricoid pressure contributed as much to the aspirations in 22 (45%) claims as did lack of it. For that very reason, use of cricoid pressure should have been listed under “Clinical Care Issues in Aspiration Claims” (table 5 of the publication), just as lack of cricoid pressure was.¹ 

In 79% of the 115 analyzed claims, only one anesthesia professional had cared for the patient, a nasogastric tube was in place immediately before the procedure in only 51% of patients with documented gastrointestinal obstruction or other acute intraabdominal pathology, and more than three attempts at endotracheal intubation were noted in 10 claims.¹  Quantitative information regarding the incidences of those clinical care issues during and in the absence of administration of cricoid pressure would help to understand why pulmonary aspirations occurred with comparable frequency under both circumstances. Possibly, clinical care issues other than use or nonuse of cricoid pressure were the primary determinants of pulmonary aspiration. After all, the three major factors considered to be important in reducing the incidence of pulmonary aspiration are experience, assistance by experienced anesthesiologists, and close supervision of inexperienced anesthesiologists.¹³ 

For the numerous documented adverse effects of cricoid pressure and its unproven clinical benefit, many anesthesiologists have abandoned this practice altogether. However, a considerable number of anesthesiologists continue with this practice for mostly medicolegal concerns. In a recent electronic survey of randomly selected Fellows of the Australian and New Zealand College of Anaesthetists designed to quantify the use of cricoid pressure in patients presumed to be at risk of gastric regurgitation, and to identify the potential impact of medicolegal concerns on clinical decision making, 267 respondents indicated to routinely apply cricoid pressure.¹⁴  Of note, for 159 (60%) of them, the potential medicolegal consequences of not using cricoid pressure in a patient who subsequently aspirates were one of the main reasons for doing so. Anesthesiologist reviewers’ judgment that omission of cricoid pressure contributes to cases of pulmonary aspiration,¹  and continued recommendation by some current guidelines of national professional societies to administer cricoid pressure,^15,16  are likely to contribute to those medicolegal concerns. The continued recommendations of British professional societies to use cricoid pressure^15,16  may explain why the United Kingdom is one of only a few countries in which cricoid pressure is still frequently applied, especially when compared with other European countries. In a questionnaire distributed electronically to instructors of the European Trauma Course, the use of cricoid pressure during rapid sequence induction in trauma patients was reported twice as often by instructors from the United Kingdom (83.1%) compared with those from all other countries (39.4%), with the lowest use in Denmark (12.5%).¹⁷ 

In the absence of conclusive evidence for a benefit of use of cricoid pressure, use of this practice for mostly medicolegal reasons is of concern. Several professional societies have recognized this dilemma and adjusted their recommendations accordingly. For example, the 2010 Scandinavian Clinical Practice Guidelines on General Anesthesia for Emergency Situations,¹⁸  the 2015 Guideline on Airway Management released by the Board of the German Society of Anesthesiology and Intensive Care Medicine,¹⁹  and the 2021 updated consensus-based recommendations for management of the difficult airway by the Canadian Airway Focus Group²⁰  no longer recommend routine application of cricoid pressure. The 2021 European Resuscitation Council Guidelines for Adult Advanced Life Support specifically discourage the use of cricoid pressure altogether.²¹ 

The use of cricoid pressure as an essential component of rapid sequence induction is decreasing.^17,22  Guidelines must be phrased in a manner that clearly reflect existing scientific evidence. In the absence of conclusive evidence of a benefit of cricoid pressure, but with evidence of numerous adverse effects of it,^23,24  lack of its application should per se no longer be considered a contributory factor to pulmonary aspiration. Anesthesiologists who are convinced that the documented disadvantages of cricoid pressure outweigh the postulated advantages should be able to exercise their judgment without fear of medicolegal consequences. “Expert” opinion must be based on conclusive scientific evidence. Otherwise, traditional practice considered “safe practice” may actually be compromising safe practice.²⁵ 

The author declares no competing interests.