Controversy on cricoid pressure

1. Cricoid pressure : Yes or No ?
Venugopalan.P.P
DA,DNB,MNAMS,MEM[GWU}
Director ,Emergency medicine ,Aster DM Health care
Deputy director MIMS Academy
Executive Director ,ANGELS
PG Teacher –NBE
Site Director –MEM-GWU
India

2. Focus
• What is it ?
• Why Cricoid pressure?
• What are the
controversies?
• Does it really helpful or
not?

3. 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

4. Brian A Sellick 1918-
1996, London
Anesthesiologist

5. 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.

6. Cricoid pressure

7. 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.”

8. 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.”

9. 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

10. 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.

11. 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

12. 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.

13. 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.

14. 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.

15. "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

16. BURP

17. 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?

18. 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

19. 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

20. 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.

21. 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.

22. 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.

23. 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.

24. 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.

25. 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.

26. 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.

27. 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.

28. • 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-

29. 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

30. 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.

31. 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

32. 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

33. 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

34. 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.

35. 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

36. 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

37. 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.

38. 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

39. 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.

40. 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.

41. 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

42. 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.

43. 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

44. 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

45. www.drvenu.net
Thank
you so
much