http://www.scielo.br/scielo.php?scr...0034-70942008000600010&lng=en&nrm=iso&tlng=en
http://www3.interscience.wiley.com/cgi-bin/fulltext/118802143/HTMLSTART
Interesting stuff in these reviews. Apparently, 20 N of force on the cricoid hurts in a conscious patient, 30 is recommended, and 40 starts interfering with intubation. And on top of that, positioning matters. The second review talks about a study that tested periop RNs, and about others that tested residents and anesthesiologists. All three concluded that it needs specific training, particularly in the amount of force applied, and both reviews have suggestions for training devices.
In short, it's not something that most basics can be trusted with, and even if it were, it's not clear how useful it is.
"Vanner e Pryle 19 observed that 30 N (equivalent to 3 kg) was the necessary force that should be applied on the cricoid cartilage to prevent regurgitation of NS in 10 cadavers with esophageal pressure of up to 55 cmH2O."
If these cadavers were preserved, there would be a reduction in the elasticity of the esophagus, requiring more force to close it completely. You see the same thing with the pyloric sphincter in the stomach on preserved bodies. A few other sphyncters and vaults have similar characteristics in the preserved. It makes these numbers a bit suspect in my mind.
There is also the relative viscocity of stomoach contents compared to NS. again, I would take these numbers with a grain of salt.
"In awake individuals, applying more than 20 N on the cricoid cartilage can cause pain, cough and nausea. Thus, during anesthetic induction, while the patient is awake, 10 to 20 N should be applied, and 30 to 40 N when the patient is unconscious20."
I only got to read the study out of Brazil, the other wants me to buy it. (which isn't in the plan) "can cause pain" I find a bit suspect as well. Pain being not only subjective, but I encourage anyone to experiment with the difference in reported pain in hispanic cultures compared to any other culture.
From my observations they have a broad definition of "pain" which seems to refer to anything that is abnormal. They are also extremely vocal about pain, which itself can be a way to cope with it.
I don't agree with the AHA on everything, actually, rather a few things, but they decided to put the instruction in the BLS video for healthcare providers, so at least their consensus seems to think even non emergency HCPs (like LPNs, and nursing aides) can perform it effectively and safely enough.
Anyone performing any procedure improperly creates risk. All procedures have some level of risk, as always it is a decision that has to be weighed.
Going soley on education I could make a very strong argument that only a physician should be able to care for patients, but as always. Medics talk about how little basics know, nurses, the same with medics...
Taking a leaf from Mycroftt,
"Five is four"