Cricoid pressure is invaluable when you can’t see the larynx during intubation. Having your assistant apply cricoid pressure often brings the larynx down and into view, making a challenging intubation easier. However, improperly applied pressure makes intubation harder. To be effective, cricoid pressure must be applied using the correct force, at the correct spot, using the correct angle. It therefore, requires good communication between intubator and the applier.
When Is Cricoid Pressure Useful?
A larynx that lies anterior to your field of view during laryngoscopy is called an “anterior larynx”.
An anterior larynx commonly occurs with patients with poor head positioning, obesity, larynxes located higher in the neck than average, and/or poorly developed mandibles or weak chins. Cricoid pressure works by pushing downward on selected parts of the larynx, thereby helping to bring an anterior larynx into view.
This pressure can also be used to prevent aspiration by pinching the esophagus closed. It thereby prevents passive regurgitation of trapped stomach contents.
Cricoid Pressure Technique
To apply cricoid pressure, place the thumb on one side of the cricoid cartilage and the index or ring finger on the other. Push down to force the cricoid cartilage against the vertebral column. Because the cricoid cartilage is a complete ring, this action will also seal the esophagus. Unless requested to, push directly downward, not toward either side. Pushing to the side can make insertion more difficult by curving the path that the tube must take.
Use Gentle Cricoid Pressure In A Child
The pediatric larynx is small, soft and easily deformed. Placing cricoid pressure in an infant often requires just one finger and a very gentle touch. For toddlers and older children use one or two fingers as appropriate.
How And Where You Press Matters
During intubation, the intubator is the only one with a view of the oropharynx. The helper is working blindly. Therefore the intubator must direct the person applying cricoid pressure on any changes to the amount of pressure or the angle of applied pressure. A small amount of change will often produce a big shift in the location, and therefore, the visibility of the glottic opening. The person applying the cricoid must therefore make small changes and listen carefully to feedback.
Find an animation of cricoid pressure here.
Right and left are reversed since intubator and helper face each other. It’s essential for the intubator to provide clear directional instructions.
Many experienced intubators start by placing their own cricoid pressure with their right hand while doing laryngoscopy with their left. Once they see the larynx, they then have their helper mimic their finger position.
The helper must pay close attention to both the placement of the intubator’s fingers as well as the angle of pressure or the view may worsen when they take over the pressure.
Be careful to avoid moving or rocking the laryngoscope, or the patient’s head, during these maneuvers.
Protection From Aspiration
Apply pressure to the cricoid ring to protect against aspiration. While very effective against passive regurgitation, you should release cricoid pressure if the patient actively vomits. The obstructed esophagus might rupture because of high pressure.
The B.U.R.P Maneuver
If cricoid pressure fails to improve the view, ask your helper to press instead on the thyroid cartilage, a maneuver is called B.U.R.P.
- Backward against the vertebral column,
- Upwards toward the head,
- Rightwards to the patient’s right side, as a constant
Risks of Cricoid Pressure
Use cricoid pressure and BURP very cautiously, if at all, when there is an upper airway foreign body, laryngeal injury, or if there is risk of cervical spine injury.
No matter how useful cricoid pressure usually is, it will occasionally prevent passage of the endotracheal tube. Cricoid pressure will sometimes pinch a child’s soft airway closed. Sometimes the angle created by the downward displacement is too acute, preventing entry of the tube. This is especially true when inexperienced helpers push the cricoid cartilage off to the side. The intubator may ask the assistant to lighten the pressure, or to release pressure entirely to see if it helps. If something isn’t working, don’t be afraid to change.
Maintain Cricoid Pressure Until Told To Release It
Always maintain cricoid pressure until instructed to release it.
During intubation, the intubator will insert the tip of the endotracheal tube in to the larynx. The intubator will then often back the stylet out 1-2 cm to soften the tip before advancing the tube completely into the trachea. The helper providing cricoid pressure often assists with the removal of the stylet. The helper must maintain pressure during this maneuver. Early release of pressure causes the larynx to shift upward again — losing visualization and potentially dislodging the tip of the tube. Esophageal intubation can occur.
In addition, if passive regurgitation is a risk, the intubator will want to verify endotracheal placement before release .
Assisting Intubation Requires Understanding What The Intubator Is Doing
I find that the people helping with an intubation can be more effective if they understand some basics of what the intubator is doing. To read an illustrated beginners guide to intubation check put this article.
In summary, cricoid pressure is an invaluable tool during intubation. However, its success relies on good technique and excellent communication and teamwork.