Cricoid pressure is a technique where you press on a specific ring of cartilage in the neck to compress the food pipe against the spine, blocking stomach contents from reaching the lungs. It’s used during emergency airway management, most often during rapid sequence intubation when a patient is at risk of vomiting and aspirating. The technique requires precise finger placement, the right amount of force, and correct timing to be effective without interfering with intubation.
Finding the Cricoid Cartilage
The cricoid cartilage sits just below the larger thyroid cartilage, commonly known as the Adam’s apple. It’s a complete ring of cartilage shaped like a signet ring, with a narrow band in front and a broader plate in back. To locate it, start by palpating the Adam’s apple, then slide your fingers downward. You’ll feel a small dip, which is the cricothyroid membrane, roughly 2 cm below the thyroid cartilage. Continue just past that dip and you’ll land on the firm, rounded ridge of the cricoid ring. It sits at the level of the C6 vertebra in the neck.
A common mistake is pressing on the Adam’s apple itself. The target is specifically the cricoid cartilage below it. The cricoid is the only cartilage ring in the airway that forms a complete circle, which is what makes it firm enough to transmit backward pressure onto the structures behind it.
Finger Placement and Direction of Force
Place the pad of your thumb and index finger on either side of the cricoid cartilage. Some practitioners use a single-finger technique with the index or middle finger centered on the front of the ring, but the thumb-and-index-finger approach is the standard method described in training programs. Your fingertips should rest directly on the cartilage, not above or below it.
The force must be directed straight backward, toward the spine. Not upward, not downward along the neck, and not to either side. The goal is to push the cricoid ring posteriorly so it compresses the upper food pipe against the vertebral body behind it. Pressing in the wrong direction reduces effectiveness and can distort the airway.
How Much Force to Apply
The recommended force depends on whether the patient is awake or unconscious. For an awake patient, apply 10 to 20 newtons, which translates to roughly 1 to 2 kilograms of pressure. This lighter touch prevents gagging or discomfort. Once the patient loses consciousness, increase to 30 to 40 newtons, or about 3 to 4 kilograms.
To calibrate what that feels like, a common training method is pressing your fingers onto a kitchen scale. Aim for the scale to read about 3 to 4 kilograms while maintaining a steady push. This gives you a physical reference point, because most people significantly over- or under-apply pressure without practice. Too little force won’t occlude the food pipe. Too much can obstruct the airway, make ventilation difficult, and interfere with the intubator’s view of the vocal cords.
When to Start and When to Release
During rapid sequence intubation, cricoid pressure is typically applied at the moment the patient loses consciousness, though some protocols call for starting with lighter pressure just before induction. The pressure stays on continuously through the administration of the paralytic medication and during the intubation attempt itself.
You release only after the breathing tube is confirmed to be correctly placed in the trachea. Confirmation involves listening for breath sounds on both sides of the chest and watching for chest wall movement with ventilation. Releasing too early, before the tube is secured and confirmed, leaves the patient vulnerable to aspiration during the window when their protective reflexes are absent.
How the Technique Works
The original idea, proposed by Brian Sellick in 1961, was straightforward: the cricoid ring sits directly in front of the food pipe, so pushing it backward would pinch the food pipe shut against the spine. The anatomy turns out to be slightly more complex than that. The food pipe actually begins just below the level of the cricoid ring, so the structure being compressed is more accurately the lower throat (hypopharynx) rather than the esophagus itself.
The cricopharyngeal muscle, which wraps around the back and sides of the lower throat at the bottom edge of the cricoid ring, plays a key role. When pressure is applied, this muscular ring collapses into a kidney shape, sealing off the passage. A band of dense tissue connects the cricoid cartilage to these surrounding structures, keeping them in a fixed relationship so that pushing the cartilage reliably compresses the soft tissue behind it.
Does It Actually Prevent Aspiration?
The largest trial to test cricoid pressure, known as the IRIS trial, randomized 3,472 patients undergoing rapid sequence intubation to receive either real cricoid pressure or a sham procedure where fingers were placed on the cartilage without meaningful force. Aspiration occurred in 0.6% of patients receiving real cricoid pressure and 0.5% of those receiving the sham. The study could not prove that skipping cricoid pressure was safe (it failed to meet its statistical threshold for noninferiority), but the raw difference between groups was extremely small.
This result has fueled ongoing debate in anesthesia and emergency medicine. Aspiration during intubation is rare to begin with, making it difficult to prove or disprove protection in a clinical trial. Many institutions continue to teach and use cricoid pressure as a precaution, particularly in patients with full stomachs, while acknowledging the evidence is less definitive than once assumed.
Risks of Incorrect Application
Cricoid pressure can make intubation harder when applied poorly. Because the technique physically compresses structures in the throat, it can worsen the intubator’s view of the vocal cords, especially with certain video laryngoscope designs. Studies using the Cormack-Lehane grading system (a scale clinicians use to rate how well they can see the vocal cords) have found that cricoid pressure either has no effect or actively degrades the view depending on the device being used. It can also force the vocal cords together, narrowing the opening for the breathing tube and prolonging the time it takes to intubate.
If the person applying pressure uses too much force, it can obstruct the airway enough to make bag-mask ventilation ineffective. In an emergency where the patient cannot be intubated and cannot be ventilated, excessive cricoid pressure can make a bad situation worse. If the intubator is having difficulty, they may ask you to reduce or release the pressure.
When Cricoid Pressure Should Not Be Used
Three situations are clear contraindications. First, if there is suspected injury to the cricoid cartilage or trachea, applying external force risks worsening the damage or causing a complete airway disruption. Second, cricoid pressure should not be applied during active vomiting. The force can trap vomit behind the compression point, potentially rupturing the food pipe rather than preventing aspiration. If a patient begins to vomit, pressure must be released immediately. Third, unstable cervical spine injuries are a contraindication because the backward force could worsen spinal displacement.