Cricoid pressure during the rapid sequence intubation: Another “bubbameisa”?

Jayant K. Deshpande MD and Myron Yaster MD

Welcome back from the SPA/SPPM/CCAS meetings! They were fantastic and over the next week or two I will post some pictures and review some of the meeting highlights.

My mother Sally, of blessed memory, was absolutely convinced that if I (MY) went out to play with wet hair, I would catch a cold.  I have no idea where or how this old wive’s tale (in Yiddish a “bubbameisa”) came from, but it was “truth” in Sally’s home until her dying day. No amount of arguing or explaining that colds came from viruses would change her mind.  Which brings me once again to an anesthetic management bubbameisa that will not go away.  Many of us still adhere almost religiously to a variety of fundamental beliefs and practices, really dogmas, that we inherited from our founding fathers/mothers that often have no proven merit.  We discussed some of these myths/bubbameisas in previous Pediatric Anesthesia Articles of the Day, particularly those involving NPO guidelines and preoxygenating with 100% FiO2 (rather than 80%).  In today’s PAAD, I’ve asked Jay Deshpande, one of my closest friends, a previous SPA president, and Robert M. Smith award winner, who is an expert on quality and safety issues to review a recent review article on cricoid pressure (CP).  Fundamentally, this article asks the question: “Is the need for CP in a rapid sequence induction efficacious or even necessary? Or in the spirit of the PAAD, is is another bubbameisa? Spoiler alert:  In much of the rest of the world CP has already been abandoned.  Myron Yaster MD

Original review article

Marko Zdravkovic, Mark J Rice, Sorin J Brull.  The Clinical Use of Cricoid Pressure: First, Do No Harm. Anesth Analg. 2021 Jan;132(1):261-267. PMID: 31397697

Today’s PAAD is a review mainly focusing on adult patients. The topic piqued our interest because more than sixty years after it was first described, the effectiveness of Sellick’s maneuver (external cricoid pressure aimed at occluding the esophagus to prevent regurgitation and aspiration during induction and intubation) continues to be debated and variably applied (have you heard the term, “modified” cricoid pressure? which to us is sort of like being a “little pregnant”. We think it should be a binary decision…either do it or don’t). Even with several hundred publications on the subject, there is insufficient evidence to fully support or debunk its use, especially in infants and children. Indeed, in much of the world other than the America, cricoid pressure even in adults is no longer recommended or used,

Facts:

a.      Sellick (1961) first reported his experience in 26 adult mainly obstetrical patients in whom he used cricoid pressure to prevent pulmonary aspiration of gastric contents by preventing gastric insufflation and passive regurgitation.

b.      Salem et al (1972) studied cricoid pressure in 8 fresh infant cadavers and 6 anesthetized infants with nasogastric tubes in place. The authors concluded that cricoid pressure was effective in occluding the esophagus in the presence or absence of a nasogastric tube and that in anaesthetized pediatric patients. Cricoid pressure did not directly occlude any of the esophageal tubes.

c.      Smith and Boyer (2002) reported that application of CP [may] worsen the ease of intubation: full visualization of the glottis was present in 91% of patients without CP, while with CP application, only 67% of patients had full visualization. Application of CP impeded tracheal tube placement in 15% of cases, requiring release.

d.      Smith et al (2003) studied the airway anatomy of 22 healthy adult volunteers using MRI. They found That the esophagus was displaced laterally relative to the cricoid in 52.6% of necks without CP and 90.5% with CP. CP shifted the esophagus relative to its initial position to the left in 68.4% of subjects and to the right in 21.1% of subjects. Unopposed esophagus was seen in 47.4% of necks without CP and 71.4% with CP. Lateral laryngeal displacement and airway compression were demonstrated in 66.7% and 81.0% of necks, respectively, as a result of CP. The authors concluded that “In the absence of CP, the esophagus was lateral to the cricoid in more than 50% of the sample. CP further displaced both the esophagus and the larynx laterally.”

e.      Ahmed et al (2009) reported a survey of pediatric anesthesiologists which found that 90% of respondents routinely use CP when there is a risk of aspiration, but only 68% believe that cricoid pressure prevents passive regurgitation. The authors conclude by challenging the usefulness and safety of CP in pediatric practice.

f.       Allen et al (2014) in an observational study found that “correct identification of the cricoid cartilage in young children is difficult using surface landmarks only. In all but one patient, there was a measurable difference found between where the cricoid was thought to be, and where it was actually visualized using ultrasound.” They concluded that “If indeed the use of cricoid pressure is deemed protective, then the second issue in this population relates to the accuracy of the localization of the cricoid cartilage. The incorrect application of pressure on the cricoid, or other cartilaginous structures (in error) of the upper airway, could lead to structural damage as well as causing airway obstruction and difficulty at laryngoscopy.”

Fundamentally, the need for cricoid pressure is to limit the risk of pulmonary aspiration of gastric contents. Is aspiration really a concern in pediatric practice?

a.      Warner et al (1999) studied pulmonary aspiration of gastric contents during the perioperative courses of 56,138 consecutive patients younger than 18 years of age who underwent 63,180 general anesthetics for procedures performed in all surgical specialties over a 2 year period. They found that pulmonary aspiration occurred in 24 patients (1: 2,632 anesthetics; 0.04%). Children undergoing emergency procedures had a greater frequency of pulmonary aspiration compared to those undergoing elective procedures (1:373 vs. 1:4,544, P < 0.001). Fifteen of the 24 children who aspirated gastric contents did not develop respiratory symptoms within 2 h of aspiration, and none of these 15 developed pulmonary sequelae. Five of these 9 children who aspirated and in whom respiratory symptoms developed within 2 h subsequently had pulmonary complications treated with respiratory support (P < 0.003). Three children were treated with mechanical ventilation for more than 48 h, but no child died of sequelae of pulmonary aspiration. The authors concluded that the frequency of perioperative pulmonary aspiration in children was quite low. Serious respiratory morbidity was rare, and there were no associated deaths.

b.      A Cochrane database systematic review (2015) could find only 1 relevant article out of 493 publications that met the criteria for a randomized control trial (highest level of evidence), but the outcomes of that study only focused on systolic blood pressure and heart rate. The authors concluded that, “There is currently no information available from published RCTs on clinically relevant outcome measures with respect to the application of cricoid pressure during RSI in the context of endotracheal intubation. On the basis of the findings of non-RCT literature, however, cricoid pressure may not be necessary to undertake RSI safely.”

Various consensus recommendations have been published reflecting existing data and evolving practice.

a.      Scandinavian guidelines (Jensen et al 2010) consider CP use up to “individual judgment” and also recommend its release if ventilation or intubation is difficult.

b.      The Difficult Airway Society guidelines (Frerk et al 2015) reconfirmed that CP should be attempted during the rapid sequence induction and intubation but released if needed to improve the laryngoscopic view.

c.      Salem et al (2017) reviewed the current controversies surrounding use of CP concluding that “Most of these complications are caused by excessive or inadequate force or by misapplication of cricoid pressure. Because a simple-to-use and reliable cricoid pressure device is not commercially available, regular training of personnel, using technology-enhanced cricoid pressure simulation, is required. The current status of cricoid pressure and objectives for future cricoid pressure–related research are also discussed.”

d.     European guidelines (Van de Voorde et al 2021) state, “The 2020 ILCOR EvUp (PLS 376) confirmed the earlier recommendation to discontinue cricoid pressure if it impedes ventilation or interferes with the speed or ease of intubation.  We … could not find sufficient evidence to recommend the use of cricoid pressure to prevent regurgitation or aspiration during rapid sequence or emergent TI in children. It might impair airway handling in children and infants in the emergency setting.”

So, readers: what should we make of all of this? We would like to hear from you: What should we do in clinical practice or better said, what do you do in your practice? Send your responses to the PAAD or to me (MY) directly (myasterster@gmail.com) and I will post in an upcoming Reader response PAAD.  Myron Yaster MD and Jay Deshpande  MD

References:

1.      Zradavkovic et al. The Clinical Use of Cricoid Pressure: First, Do No Harm. Anesth Analg 2021;132:261–7

2.      Sellick BA. Cricoid pressure to prevent regurgitation of stomach contents during induction of anaesthesia. Lancet 1961;278:404–6

3.      Salem MR et al. Efficacy of cricoid pressure in preventing aspiration of gastric contents in paediatric patients. Br J Anaesth 1972;44(4):401-4.

4.      Smith CE, Boyer D.  Cricoid pressure decreases ease of tracheal intubation using fibreoptic laryngoscopy (WuScope System™) Can J Anesth 2002:49:614–619.

5.      Smith KJ et al. Cricoid Pressure Displaces the Esophagus: An Observational Study Using Magnetic Resonance Imaging. Anesthesiology 2003; 99:60–4

6.      Ahmed Z, Zestos M, Chidiac E, Lerman J. A survey of cricoid pressure use among pediatric anesthesiologists [letter]. Pediatr Anaesth 2009;18:183–5

7.      Allen et al Eur J Anaesthesiol 2014; 31:333–342Salem et Anesthesiology 2017; 126:738-52

8.      Warner MA, Warner ME, Warner DO, Warner LO, Warner EJ. Perioperative pulmonary aspiration in infants and children. Anesthesiology. 1999 Jan;90(1):66-71

9.      Algie CM et al. Effectiveness and risks of cricoid pressure during rapid sequence induction for endotracheal intubation. Cochrane Database of Systematic Reviews.2015;11:1465-1858.

10.   Frerk C, Mitchell VS, McNarry AF, et al; Difficult Airway Society intubation guidelines working  group. Difficult airway society 2015 guidelines for management of unanticipated difficult intubation in adults. Br J Anaesth. 2015;115:827–848.

11.   Jensen AG, Callesen T, Hagemo JS, Hreinsson K, Lund V, Nordmark J; Clinical Practice Committee of the Scandinavian Society of Anaesthesiology and Intensive Care Medicine. Scandinavian clinical practice guidelines on general anaesthesia for emergency situations. Acta Anaesthesiol Scand. 2010;54:922–950.

12.   Salem MR et al. Cricoid Pressure Controversies. Anesthesiology 2017; 126:738-52.

13.   Van de Voorde P et al. European Resuscitation Council Guidelines 2021: Paediatric Life Support. Resuscitation 2021;161:327-387.