Sunday, December 11, 2011

Protection via Violation: A Sheriff Joe Arpaio approach to the Airway

Left: Posterior arytenoid web developed after a 40 minute intubation
Right: After endoscopic laser therapy
The subject of overdoses segues me to another topic of interest to the skeptical observer in the emergency department (ED) and intensive care unit (ICU).  Patients with alcohol intoxication, drug overdose, and various other maladies that cause decreased level of consciousness (LOC) are often intubated (a breathing tube inserted through the vocal cords and into the trachea [airway]) so as to "protect the airway".  Under normal conditions, there are powerful reflexes in the oropharynx, larynx, and trachea that cause you to gag and cough to keep everything but air out of the airway to prevent the development of an obstruction or pneumonia.  Because of this, powerful sedatives and often paralytic medications have to be given to a person to enable the insertion of the tube - otherwise it will be violently rejected by these reflexes.  Various conditions, chief among them drug and medication effects but including even normal sleep, can cause a depression of the intensity of these reflexes, which often arouses concern that patients with decreased LOC will aspirate (get liquid or solid material in the form of saliva, mucous, food, etc. into the airway).  By intubating such patients with a tube that effectively seals off the airway (by means of a balloon that is inflated at the end of the tube), it is thought that the airway is thusly "protected".

Setting aside the question of whether violating the airway by putting a tube through the vocal cords, the final gatekeepers of the airway proper, is actually protective (a very provocative question indeed), this practice in real life is bedeviled by several hobgoblins that make me wary of it.  Oftentimes, when asked to admit a patient who was intubated for "airway protection" (AWP), I inquire as to whether the intubation was performed without the administration of sedatives and paralytics, reasoning that if the airway reflexes were so depressed that AWP was required, that there should have been no need to further depress the reflexes to get the tube in.  The response is often one of incredulity, as if the question were rhetorical.  "Well, heavens no, he was fighting like mad, we had to put him down with such and such [powerful sedatives] to get him to cooperate."

Well son of a big rotten egg, are you KIDDING me? Your reasoning is that this person needs a tube in his airway to protect it, but the only way you can get it in there is to administer sedatives to prevent him from protecting it?  This is a miserable and felonious violation of logic.  Unelss you wish to argue that securing any airway is most safely performed by rapid sequence intubation (RSI), essentially with rapidly induced sedation and paralysis.  And there is evidence for that.  But there's more to this story.

There are other telltale signs that logic and reason were vacationing in the Bahamas (or that we're speaking the language of pretenses and euphemisms and AWP is a code word for something else) when intubation was performed for AWP.  One is when after the intubation, heavy sedatives (such as propofol or "Milk of Michael") are administered to calm the patient.  The reason that they become agitated after intubation is because they're now trying violently to protect an airway that has a half-inch hose violating it!  That's uncomfortable.  When such patients come to the ICU, we oftentimes simply turn off the propofol and remove the tube.

The fact is that a proper assessment of whether the patient is truly protecting his airway is not always (dare I say rarely?) undertaken, and rather a System 1 or intuitive assessment is made (as contrasted with a System 2 or deliberative assessment.  See: Thinking Fast and Slow ).   It has been observed that they are often the more difficult or belligerent patients who are  intubated for AWP.  Perhaps the concern it less for protecting the airway than it is for silencing it.

2 comments:

  1. They do really seem the kind of patients ready to put on a scene.

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  2. I need to share this with my residents! When we get an admission to the MICU for a drug overdose (with nothing complicating it, like aspiration, shock, etc), the answer to the question of what sedative to use is, "nothing." When the patient is awake enough to annoy the nurses, he's awake enough to be extubated.

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