Cricoid Pressure During Intubation: Is It Still Recommended?

Cricoid pressure during intubation occupies an increasingly uncomfortable position in modern anesthesia practice: widely taught, variably applied, and supported by surprisingly thin evidence after more than six decades of use. Guidelines from major anesthesia societies now offer mixed or weakened recommendations, and a landmark 2018 randomized trial failed to show that the technique prevents aspiration better than a sham maneuver. Yet roughly three-quarters of surveyed anesthesiologists still use it routinely, many driven in part by fear of litigation rather than confidence that it works.

What Cricoid Pressure Is Supposed to Do

The technique, often called Sellick’s maneuver after the British anesthetist who popularized it in 1961, involves pressing on the cricoid cartilage, the ring-shaped structure at the base of the larynx, to compress the esophagus against the vertebral column behind it. The goal is to create a physical seal that prevents stomach contents from traveling up the esophagus and entering the airway during the vulnerable window of general anesthesia induction, when a patient is unconscious but not yet intubated. It became a core part of rapid sequence induction, the fast-track intubation protocol used in patients considered at high risk of vomiting, such as those with full stomachs, bowel obstructions, or emergencies requiring urgent surgery.

For decades, Sellick’s maneuver was treated as a non-negotiable safety step. The logic seemed straightforward: press down on the right spot, pinch the esophagus shut, and gastric contents stay where they belong. But the anatomical reality turns out to be far less cooperative than the theory suggests.

The Esophagus Does Not Sit Where Textbooks Say It Does

A core assumption behind cricoid pressure is that the esophagus sits neatly behind the cricoid cartilage, positioned so that downward pressure compresses it directly against the spine. MRI-based research showed this is often not the case. In one study, the esophagus was already displaced to one side relative to the cricoid in more than half of subjects before any pressure was applied, and that lateral displacement jumped to over 90% once cricoid pressure was actually used.¹ Instead of compressing the esophagus against the spine, the force was pushing it off to the side, potentially leaving it open.

Ultrasound studies have reinforced this finding in living patients. In one investigation, only about 20% of people had an esophagus sitting directly behind the trachea at baseline. When cricoid pressure was applied, the esophagus shifted further to the left in half of the subjects, and only 4% still had a centrally positioned esophagus. Every participant in that study was able to swallow liquid even with cricoid pressure applied.² A separate ultrasound-guided study found that after anesthesia induction, roughly two-thirds of patients had an off-center esophagus. Cricoid pressure successfully occluded the esophagus in all patients whose esophagus happened to be centrally positioned, but the success rate dropped to about 27% in patients whose esophagus was already off to one side.³

This means the maneuver’s fundamental mechanism, physically sealing the esophagus, fails in the majority of patients simply because of how their anatomy is arranged. The esophagus slips sideways, and the compressive force misses its target.

The Largest Randomized Trial Found No Clear Benefit

The strongest piece of clinical evidence against cricoid pressure came from the IRIS trial, a multicenter randomized study comparing real cricoid pressure to a sham procedure during rapid sequence induction. Among roughly 3,500 patients, pulmonary aspiration occurred in about 0.6% of those who received actual cricoid pressure and about 0.5% of those who received only the sham. The trial could not demonstrate that omitting cricoid pressure was safe (in statistical terms, it failed a noninferiority test), but the raw numbers showed no meaningful protective effect either.⁴

The trial’s somewhat ambiguous statistical result left the debate open. Proponents point out that it did not prove cricoid pressure is useless; critics counter that a technique performed millions of times a year should have a clearer signal of benefit after a trial of this size. What the IRIS trial did accomplish was to shift the burden of proof. Before IRIS, cricoid pressure was assumed to help until proven otherwise. After IRIS, many clinicians began asking whether the evidence justifies a technique that carries its own set of downsides.

How Cricoid Pressure Interferes with Intubation

If cricoid pressure offered a strong protective benefit, its drawbacks might be worth tolerating. But a systematic review and meta-analysis pooling five randomized trials found no significant difference in the rate of first-attempt intubation success between patients who received cricoid pressure and those who did not. There was also no significant difference in the rate of poor laryngoscopic views. What the meta-analysis did find was that intubation took slightly longer on the first attempt, about four and a half seconds more, and the risk of post-procedure hoarseness was higher in the cricoid pressure group.⁵

The picture gets more complicated with video laryngoscopy, which has become increasingly common. One study found that while cricoid pressure improved or maintained the laryngeal view during direct laryngoscopy and one type of video laryngoscope, it worsened the view in 30% of patients when a GlideScope was used.⁶ Another study using the GlideScope found no statistically significant overall difference, though views worsened in about 20% of patients and improved in about 39%.⁷ The inconsistency across devices matters because the choice of laryngoscope varies by setting, provider, and patient.

Beyond the view, cricoid pressure can substantially impair mask ventilation, the critical bridge of oxygen delivery before the breathing tube goes in. In one clinical evaluation, adequate bag-mask ventilation was achieved in 98% of patients without cricoid pressure but in only about 42% of patients with it applied.⁸ That same study found that with a supraglottic airway device in place, cricoid pressure significantly reduced the volume of air reaching the lungs and increased airway pressures. In a cannot-intubate scenario where mask ventilation is the lifeline, cricoid pressure can make matters worse.

A Paradox at the Lower Esophageal Sphincter

Here’s a finding that surprised many clinicians when it emerged: cricoid pressure may actually weaken the body’s own natural barrier against reflux. The lower esophageal sphincter, a muscular ring at the bottom of the esophagus where it meets the stomach, provides a built-in defense against gastric contents moving upward. Research in human subjects found that applying cricoid pressure at the recommended force of 30 to 40 newtons decreased lower esophageal sphincter pressure from a baseline of about 24 mmHg to roughly 12 to 15 mmHg.⁹ Animal studies showed a similar pattern, with cricoid pressure reducing sphincter tone and lowering the overall barrier pressure that keeps stomach contents from refluxing.¹⁰

This creates an uncomfortable paradox. The technique meant to mechanically block regurgitation at the cricoid level may simultaneously open the door to regurgitation lower down. Whether the net effect is protective, harmful, or neutral in real patients remains unclear, but the finding undercuts the simple “press here, block there” logic that underpins the whole rationale.

Rare but Serious Complications

Most discussions of cricoid pressure focus on whether it works. Less often discussed are the cases where it causes direct harm. A pressure of 40 newtons, the upper end of what is traditionally recommended, can distort the larynx and complicate intubation. Reported complications include esophageal rupture and worsening of previously undetected airway injuries.¹¹ In one case report, a patient who was bleeding from a gastric ulcer vomited during cricoid pressure application. The force against the closed esophagus caused a lower esophageal tear, which led to fatal mediastinitis despite surgical repair.¹²

These events are rare, and the case report literature always risks overstating dangers by focusing on dramatic outliers. Still, when a technique’s benefit is unproven and its mechanism is anatomically unreliable, even rare harm deserves weight in the calculation.

Almost Nobody Applies It Correctly

Even if cricoid pressure worked perfectly in theory, the real-world execution is often poor. The recommended force is about 30 newtons for an adult, roughly the weight of pressing down with three kilograms. Studies consistently find that healthcare providers struggle to apply the right amount of force to the right location. In one emergency department study, only about half of staff could correctly identify the cricoid cartilage, and just 16% could identify the target pressure. Training helped in the short term, with correct pressure rates jumping from about 30-38% at baseline to 88% immediately after hands-on instruction, but the improvement faded within weeks.¹³

A simulation-based study set an even stricter standard, requiring providers to maintain appropriate force continuously rather than just hitting the right pressure at a single moment. At baseline, fewer than 2% of measurement cycles met the target. After education and practice, performance improved, but even at their best, no single participant achieved the study’s predefined threshold for proficiency.¹⁴ The implication is stark: in the real clinical environment, with time pressure and stress, the force being applied is probably wrong more often than it is right.

Efforts to address this gap have led to novel training devices. A low-cost cricoid pressure simulator tested across four hospitals in England found that only about 55% of providers could correctly describe where the cricoid ring is, and just 28% could describe the proper force. After self-calibration on the simulator, the gap between actual and target force narrowed, and the variability in sustained pressure improved. Nearly all participants said they would use the device for a quick calibration check before performing the technique in a real patient.¹⁵ But the larger question remains: if a technique requires a specialized training device immediately before each use to be performed adequately, is it a practical safety measure for routine clinical care?

Children and Pregnant Patients

Cricoid pressure in pediatric patients raises unique concerns. A large registry analysis of nearly 8,000 intubation events in critically ill children found that cricoid pressure was used in about 23% of cases. In unadjusted numbers, regurgitation was actually more common in the group that received cricoid pressure than in those who did not. After adjusting for risk factors, the association weakened and was no longer statistically significant by conventional thresholds, though a sensitivity analysis in matched groups still pointed toward slightly higher regurgitation rates with the technique.¹⁶ This does not prove that cricoid pressure causes regurgitation in children, but it certainly does not support a protective effect.

Older cadaver-based research in infants did suggest that cricoid pressure could effectively occlude the esophagus, even with a nasogastric tube in place.¹⁷ The tension between these older cadaver findings and newer clinical data mirrors the broader story of cricoid pressure: what works on a bench or a cadaver does not always translate to a living, breathing patient in an emergency.

In obstetric anesthesia, cricoid pressure has long been considered especially important because pregnant patients are at elevated aspiration risk. Yet an observational study in an African hospital setting examining cesarean section patients found no evidence that cricoid pressure as actually practiced reduced regurgitation or maternal death, and suggested that preoperative gastric emptying might be a more effective strategy.¹⁸ This was a single-center observational study rather than a randomized trial, so the evidence is limited. But it adds to the pattern of real-world data failing to confirm the theoretical benefit.

Why So Many Providers Keep Doing It Anyway

A survey of Australian and New Zealand anesthesiologists captured the profession’s ambivalence well. About 77% said they routinely used cricoid pressure for patients considered at increased risk of regurgitation. But when asked whether they actually believed the technique reduced that risk, fewer than 40% said yes. Roughly a quarter said no, and more than a third were unsure. Among those who used it routinely, 60% acknowledged that fear of medicolegal consequences if a patient aspirated without cricoid pressure was one of their main reasons for continuing.¹⁹

The medicolegal dimension is not trivial. An analysis of closed malpractice claims found that aspiration of gastric contents accounted for about 5% of claims in a major U.S. database, with death occurring in 57% of those aspiration-related claims and permanent severe injury in another 14%. Anesthetic management was judged substandard in 59% of these cases.²⁰ In that legal environment, an anesthesiologist who omits a traditional safety step and then has a patient aspirate faces a difficult courtroom argument, even if the evidence for that step is weak. The result is a practice sustained partly by inertia and partly by defensive medicine.

Guidelines reflect this tension. A 2024 review noted that international airway management guidelines offer variable recommendations on cricoid pressure, with some endorsing it selectively, others leaving it to clinician judgment, and some explicitly noting its uncertain benefit.²¹ There is no global consensus. The direction of travel is clearly toward more skepticism and greater willingness to release or omit cricoid pressure when it interferes with airway management, but a full abandonment of the technique has not been endorsed by any major society.

BURP and Bimanual Laryngoscopy as Alternatives

One reason cricoid pressure persists is that it is sometimes confused with other external neck maneuvers that genuinely improve intubation. Backward-upward-rightward pressure, known as BURP, involves pushing on the thyroid cartilage rather than the cricoid. Unlike cricoid pressure, BURP was specifically designed to optimize the view of the vocal cords during laryngoscopy, not to prevent aspiration. Bimanual laryngoscopy, where the intubating provider uses their free hand to manipulate the larynx externally while looking through the laryngoscope, serves the same purpose. A randomized comparison of these maneuvers during direct laryngoscopy set out to determine which best optimized the laryngeal view.²²

The distinction matters because providers sometimes apply cricoid pressure under the belief that it will help them see the vocal cords better, when it was never intended for that purpose. Cricoid pressure targets a different structure at a different angle for a different reason. When a difficult view arises during intubation, releasing cricoid pressure and switching to BURP or bimanual manipulation is often the right move, but doing so can feel counterintuitive to someone trained to treat cricoid pressure as a safety requirement that must not be released.

Ultrasound-Guided Esophageal Compression

One of the more promising developments in this area is the idea of using real-time ultrasound to guide external pressure to where the esophagus actually sits, rather than assuming it is directly behind the cricoid. The ultrasound-guided approach, sometimes called paralaryngeal pressure, tailors the direction and location of force to each patient’s anatomy. In a study of 51 patients, standard cricoid pressure achieved full esophageal compression in all patients with a centrally positioned esophagus but in only about a quarter of patients whose esophagus was off to one side. Guided paralaryngeal pressure, adjusted based on real-time imaging, offered a more targeted alternative for those patients.³

This is still a research concept rather than standard practice, and adding an ultrasound step to an already time-pressured rapid sequence induction raises obvious practical questions. But it illustrates the core problem with standard cricoid pressure: a one-size-fits-all maneuver applied to variable anatomy produces variable results. If the technique has a future, it may involve personalization guided by imaging rather than blind force applied to a landmark.