M1 question here. Why do people need to fast before surgery? Is it because they might vomit during the case and choke? How would they choke? And what the heck do you do in an emergency situation in which you can't control whether or not the patient's stomach is empty?
Those are all very good questions, my friend.
Sleep's response is correct.
A stomach with a
Nachos Bellagrande in it has the potential for aspiration....and when we remove the
gag reflex with the medicines we use to render a patient
asleep and motionless, theres the potential for the stuff to come up outta the stomach, breach the unprotected larynx into the pulmonary system with resultant TBL....(
TACO BELL LUNG.)
In reality our NPO guidelines are guided more by
litiginous concern than by potential aspiration.
The chances of aspiration in a healthy patient showing up for a knee scope who ate breakfast is very low.
Not everyone is healthy, though.
Rampant obesity, diabetes, etc in our nation means we err on the side of caution......add in the high potential for a lawsuit means you, the clinician, are stripped of sound judgement, even in a healthy patient, because of our litiginous society.
In the UK, patients have tea before their surgery.
But,
uhhhh, there are no malpractice attorneys there.
Of course there are
REAL aspiration concerns....like a patient with a bowel obstruction...
In the
true full stomach cases we perform whats called a
rapid sequence intubation....
In a normal induction (induction meaning pushing drugs to render the patient unconscious and motionless) we push our IV drugs which results in unconsciousness and paralysis, ventilate with a mask for 30 seconds, maybe a minute or two, then insert the endotracheal tube.
Turns out that this act of
ventilation may work against us in a full stomach since some of the air from positive pressure ventilation makes its way into the stomach which may push stomach contents into the pharynx, and maybe into the trachea and into the lungs....
So if we're really concerned about aspiration we
preoxygenate by having the patient breathe 100% oxygen which means the patient won't desaturate so fast,
put the bed into a little
reverse Trendelenberg,
push drugs to render them unconscious and motionless,
AND WE WAIT ABOUT 30-60 SECONDS
without ventilating.
Which removes the potential for entraining air into the stomach which may push contents out.
Then we put the endotracheal tube in, inflate the cuff.
We now have a protected airway.
😀
