Written by Clay Smith
Spoon Feed
Paratracheal pressure was non-inferior to cricoid pressure in degrading direct laryngoscopic view. Many have abandoned cricoid pressure for RSI, with no ill effects, and I don’t see this replacing it.
Why does this matter?
Cricoid pressure is ineffective at reducing risk of aspiration and worsens glottic view. Paratracheal pressure (see image at the bottom) has been studied as an alternate way to reduce aspiration risk, but does it also degrade laryngoscopic (DL) view?
No pressure?
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Design: This was a randomized, double-blinded trial of 149 adults who were undergoing general anesthesia that compared the degradation of Cormack-Lehane (DL) view with paratracheal or cricoid pressure, both applied with 30N of force.
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Results: They found paratracheal vs cricoid pressure degraded the CL view on DL in 0% vs 2.9%, respectively, which was below the non-inferiority margin of 15%. Paratracheal pressure had some potential advantages over cricoid pressure when considering secondary outcomes of ease of mask ventilation and the ability to ventilate with a lower peak inspiratory pressure. They also performed ultrasound to see if the esophagus was in an anatomically leftward position and likely to be occluded by paratracheal pressure and found this was the case in 137 of 140 patients (97.9%). Three cricoid pressure patients had to have the maneuver released to pass the tube vs none of the paratracheal pressure patients.
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Implications: So, when should we use this? I have abandoned cricoid pressure, because it doesn’t make patients safer; in fact, it makes it harder to bag and to intubate. I think if you needed to bag a patient for an extended period of time, paratracheal pressure could help reduce gastric insufflation.
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Limitations: The 15% non-inferiority margin might have been a bit wide. In addition, the sample size may have been too small, as it was originally based on a calculation of a .05 1-sided α level and should have been at the .025 1-sided α level.
Source
Effect of Paratracheal Pressure on the Glottic View During Direct Laryngoscopy: A Randomized Double-Blind, Noninferiority Trial. Anesth Analg. 2021 Aug 1;133(2):491-499. doi: 10.1213/ANE.0000000000005620.
