Cricoid pressure : Yes or No ?

Venugopalan.P.PDA,DNB,MNAMS,MEM[GWU}

Director ,Emergency medicine ,Aster DM Health care Deputy director MIMS Academy

Executive Director ,ANGELS PG Teacher –NBE

Site Director –MEM-GWUIndia

Focus • What is it ?• Why Cricoid pressure? • What are the

controversies?• Does it really helpful or

not?

When looking back …

• Cricoid pressure (CP) was first described by Monro in 1774, when he used it in drowning victims to prevent gastric distention

• No other mention of the technique until 1961 when Sellick popularized this procedure to prevent regurgitation of gastric contents during anesthesia induction

Brian A Sellick 1918-1996, London Anesthesiologist

Brian A Sellick 1918-1996, London Anaesthetist

"Cricoid pressure must be exerted by an assistant. Before induction, the cricoid is palpated and lightly held between the thumb and second finger; as anaesthesia begins, pressure is exerted on the cricoid cartilage mainly by the index finger. Even a conscious patient can tolerate moderate pressure without discomfort but as soon as consciousness is lost, firm pressure can be applied without obstruction of the patient's airway. Pressure is maintained until intubation and inflation of the cuff of the endotracheal tube is complete.”Sellick BA. Cricoid pressure to control regurgitation of stomach contents during induction of anaesthesia: preliminary communication. Lancet. 1961; 2:404-406.

Cricoid pressure

How pressure on the cricoid cartlilage can occlude the esophagus

Source http://www.nda.ox.ac.uk/wfsa/html/u02/u02_b03.htm

“The esophagus is compressed between the posterior aspect of the cricoid and the vertebrae behind. The cricoid is used because it forms the only complete ring of the larynx and trachea.”

Source: http://www.nda.ox.ac.uk/wfsa/html/u02/u02_b03.htm

Correct means of hand positioning

“The cricoid is located at the level of C6. Moderate pressure may be applied before loss of consciousness, and firmer pressure maintained until the cuff of the tracheal tube is inflated.”

Source: Bryant A. Tingen MS. The use of cricoid pressure during emergency intubation. Journal of Emergency Nursing. 25(4):283-4, 1999

Incorrect (but likely still effective) hand positioning

Brian A Sellick 1918-1996, London Anaesthetist

• Sellick's seminal paper shows lateral X-rays of the neck with the esophagus containing a latex tube full of contrast medium. The effect of cricoid pressure is graphically demonstrated.

Sellick BA. Cricoid pressure to control regurgitation of stomach contents during induction of anaesthesia: preliminary communication. Lancet. 1961; 2:404-406.

Essential Elements of Cricoid Pressure

• Must apply force to the cricoid cartilage

• Must apply force in correct direction

• Must apply correct amount of force

• Must apply force for correct duration of time

How Much Force?

“A force of 30 N (3 kg) is recommended for an unconscious patient”

Clayton TJ, Vanner RG. A novel method of measuring cricoid force. Anaesthesia. 2002;57:326-9.

How Much Force? “Research recommends that 3 to 4 kg of cricoid force be applied to achieve effective esophageal occlusion”

Koziol CA, Cuddeford JD, Moos DD. Assessing the force generated with application of cricoid pressure. AORN J. 2000;72:1018-28, 1030.

How Much Force? “ ... a cricoid force of 44 N was judged to be effective in protecting the majority of adult patients from regurgitation.”

Wraight WJ, Chamney AR, Howells TH. The determination of an effective cricoid pressure. Anaesthesia. 1983;38:461-6.

"BURP" Maneuver The "BURP" maneuver consists of displacement of the larynx in 3

specific directions, posteriorly against the cervical vertebrae (Back), as far superior (Upward) as possible and slightly laterally to the right (Rightward Pressure).

In a Japanese study, both cricoid pressure and the "BURP" maneuver significantly improved laryngoscopic visualization, with the "BURP" maneuver being more effective.

Osamu Takahata, MD, Munehiro Kubota, MD, Keiko Mamiya, MD, et al. The Efficacy of the "BURP" Maneuver During a Difficult Laryngoscopy. Anesthesia Analgesia 1997:84:419-21

BURP

New concerns…. • Does CP Occlude the Esophagus? • Does CP Cause Problems With the Airway?• Does CP Reduce the Incidence of Regurgitation and Hence

Pulmonary Aspiration? What Is Its Scientific Validation?• If there Is Insufficient Evidence Confirming the Efficacy of

CP?• Is There Any Evidence That It Has Neutral/ Negative Effect

on Patient Outcome?• Can Less CP Force Prevent Regurgitation?

Ann Emerg Med. 2007 Dec;50(6):653-65. Epub 2007 Aug 3.Cricoid pressure in emergency department rapid sequence tracheal intubations: a

risk-benefit analysis.Ellis DY1, Harris T, Zideman D.

• Review analyzes the published evidence supporting cricoid pressure, along with potential problems, including increased difficulty with tracheal intubation and ventilation. According to the evidence available, the universal and continuous application of cricoid pressure during emergency airway management is questioned

Aspirations even with CP ?

• There have been reports of regurgitation of gastric contents and aspiration despite CP. Further, its effectiveness has been demonstrated only in cadavers; therefore, its efficacy lacks scientific validation

Ovassapian A, Salem MR. Sellick’s maneuver: To do or not do.Anesth Analg 2009;109:1360-2.

Vanner R. Cricoid pressure. Int J Obstet Anesth 2009;18:103-5

Does CP Occlude the Esophagus?

• A retrospective review of 51 cervical CT scans and prospective analysis of 22 cervical MRI scans revealed some degree of lateral displacement of the esophagus in 49% and 53% respectively, even in the absence of any CP.

• Application of CP increased lateral displacement of the esophagus from 53% to 91%.

•Smith KJ, Ladak S, Choi PT, Dobranowski J. The cricoid cartilage and the esophagus are not aligned in close to half of adult patients. Can J Anaesth 2002;49:503-7.•Smith KJ, Dobranowski J, Yip G, Dauphin A, Choi PT. Cricoid pressure displaces the esophagus: An observational study using magnetic resonance imaging. Anesthesiology 2003;99:60-4.

Rice et al

• Found that it was the hypopharynx and not the esophagus that was present behind the cricoid ring and was indeed compressed by CP

• Lateral movement of the esophagus from the midline when CP was applied,but the origin of the esophagus was inferior to the level of cricoid

• Study confirmed Sellick’s CP does compress the conduit between the stomach and pharynx as intended.

Rice MJ, Mancuso AA, Gibbs C, Morey TE, Gravenstein N, Deitte LA. Cricoid pressure results in compression of the postcricoid hypopharynx: The esophageal position is irrelevant. Anesth Analg 2009;109:1546-52.

Does CP Cause Problems With the Airway?

• Numerous published articles, with contradictory results

• CP may alter the upper airway anatomy and compromise laryngeal view

Ellis DY, Harris T, Zideman D. Cricoid pressure in emergency department rapid sequence tracheal intubations: A risk-benefit analysis. Ann Emerg Med 2007;50:653-65.

Evidences • A randomized study in 2003 by Noguchi et

al.designed to examine the effect of CP on passing a bougie, found that CP significantly worsened the laryngeal view

• A study combining laryngoscopy, CP force measurement and endoscopic photography down the laryngoscopic blade found that 8 of 40 patients had marked deterioration of laryngeal view

Haslam N, Parker L, Duggan JE. Effect of cricoid pressure on the view at laryngoscopy. Anaesthesia 2005;60:41-7.

Evidences

• CP interferes with laryngeal mask airway (LMA) placement and advancement of tracheal tube, makes ventilation with facemask/LMA difficult and alters laryngeal visualization by flexible bronchoscope.

Ellis DY, Harris T, Zideman D. Cricoid pressure in emergency department rapid sequence tracheal intubations: A risk-benefit analysis. Ann Emerg Med 2007;50:653-65.

Evidences

• Turgeon et al.conducted a large, randomized, double-blinded, controlled trial using 30N of CP and found no appreciable effect on tracheal intubation success, laryngeal view or time to tracheal intubation.

Turgeon AF, Nicole PC, Trépanier CA, Marcoux S, Lessard MR. Cricoid pressure does not increase the rate of failed intubation by direct laryngoscopy in adults. Anesthesiology 2005;102:315-9.

Visualization of the larynx & intubation difficult. • Excessive force

• Wrong direction of force • Application of pressure on

larynx rather than cricoid ring

Vanner RG, Asai T. Safe use of cricoid pressure. Anaesthesia 1999;54:1-3.

A survey done in England

220 professionals were asked about the adequate force to be used in CP. Answers varied from 1-44N for awake and 2-80N for unconscious patients. Many did not know the force applied or described it as “enough,” “enough force to break an egg” or “varies.”

Morris J, Cook TM. Rapid sequence induction: A national survey of practice. Anaesthesia 2001;56:1090-7.

• Traditional teaching - required force has been 44N and this force was recommended by Wraight et al.

• Excessive force, especially > 40N, can compromise airway patency and cause difficulty with tracheal intubation.

Wraight WJ, Chamney AR, Howells TH. The determination of an effective cricoid pressure. Anaesthesia 1983;38:461-

Can Less CP Force Prevent Regurgitation?

• Wraight et al. have shown that 34N occluded a manometry catheter behind the cricoid cartilage at pressure >30 mm of Hg in all patients.

• Vanner et al. cricoid force of 30N occluded the manometry catheter with a pressure >25 mm of Hg in all patients

So what can be recommended ?

• Apply 10N of force to the cricoid cartilage in an awake patient

• To increase this force to 30N once the patient loses consciousness.

Vanner RG, Asai T. Safe use of cricoid pressure. Anaesthesia 1999;54:1-3.

Curtis Lester Mendelson

Between 1932 and 1945, 66 cases of aspiration occurred during obstetrical anesthesia at New York Hospital.

Mendelson CL The aspiration of stomach contents into the lungs during obstetric anesthesia. Am J Obstet Gynecol 52:191 1946

The Problem

General anesthesia may predispose patients to aspiration of gastroesophageal contents because of depression of protective reflexes during loss of consciousness and the use of neuromuscular blockade.

Ng A. Smith G. Gastroesophageal reflux and aspiration of gastric contents in anesthetic practice. Anesthesia & Analgesia. 93(2):494-513, 2001

The Problem

Some patients may be at increased risk of pulmonary aspiration because of retention of gastric contents caused by pain, inadequate fasting, gastrointestinal pathology resulting in reduced gastric emptying, and gastroesophageal reflux.

Ng A. Smith G. Gastroesophageal reflux and aspiration of gastric contents in anesthetic practice. Anesthesia & Analgesia. 93(2):494-513, 2001

Does CP Reduce the Incidence of Regurgitation and Hence Pulmonary Aspiration?

CP is effective, is almost exclusively based on cadaver studies and case reports of regurgitation seen on release of CP after tracheal intubation

Vanner R. Cricoid pressure. Int J Obstet Anesth 2009;18:103-5.

Does CP Reduce the Incidence of Regurgitation and Hence Pulmonary Aspiration?

• Effectiveness of CP comes from studies that unequivocally demonstrate its efficacy in preventing gastric inflation in anesthetized children and adults

• Inconceivable that a maneuver effective in preventing gastric inflation during manual ventilation

Ovassapian A, Salem MR. Sellick’s maneuver: To do or not do.Anesth Analg 2009;109:1360-2

Does CP Reduce the Incidence of Regurgitation and Hence Pulmonary Aspiration?

• Two systemic reviews concluded that there was no evidence for or against the application of CP

• Three reviews on rapid sequence induction and CP - pointed out that no published randomized controlled trials comparing the incidence of regurgitation on induction, with and without CP in patients at high risk of regurgitation

Nidhi Bhatia, Hemant Bhagat, Indu Sen: Cricoid pressure: Where do we stand?Journal of Anaesthesiology Clinical Pharmacology | January-March 2014 | Vol 30 | Issue 1

Cricoid pressure • Review of almost 5000

general anesthetics for obstetrics in Malawi,11 deaths were attributed to regurgitation and 9 had CP applied

• Pulmonary aspiration despite CP may reflect concomitant reflex relaxation of the lower esophageal sphincter

Is there any evidence that CP has Neutral/ Negative Effect on Patient Outcome?

Fenton PM, Reynolds F. Life-saving or ineffective? An observational study of the use of cricoid pressure and maternal outcome in an African setting. Int J Obstet Anesth 2009;18:106-10.

Failed CP??• Fixed failure rate may exist

even when CP is properly applied

Other probabilities • CP is not applied properly• Released prematurely• Aspiration occurs at some

time other than induction, i.e., prior to induction or at extubation

Judgment “We cannot assert that CP is

not effective until trials have been performed, especially as it is an integral part of anesthetic technique that has been associated with a reduced maternal death rate from aspiration since the 1960’s.”

Vanner R. Cricoid pressure. Int J Obstet Anesth 2009;18:103-5.

Where we are now?

• Currently, insufficient evidence to advocate or abandon the use of CP to prevent passive regurgitation.

• Solid evidence that CP is applied inconsistently by majority of the practitioners.

• If we are not able to perform it as recommended, whether or not it is a useful technique becomes a secondary argument.

What is the best ?

The potential benefits of CP

in minimizing gastric distention and possibly lessening the risk of aspiration should be balanced against impaired gas exchange and ventilation

The risks and benefits of CP

• Change strategies not only between patients, but also during a prolonged and problematic tracheal intubation sequence .

• Release CP , if there is any difficulty in either intubating or ventilating the patient.

Concluding • Properly applied CP

probably is effective at preventing regurgitation on induction

• Teaching proper technique of CP application, knowing which patients require CP and focusing on the risk of aspiration other than induction is important

Most importantly • Most of the CP reviews

from anesthesia side • Not much studies on ER

ground .• Need quality ER based

trails • AHA 2010 guidelines de-

emphasis CP during ACLS efforts

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Thank you so much