I spent the first four months of my emergency medicine residency slowly but steadily working myself into a nervous frenzy. Not because of the stress of being a young doctor, not because of the impending doom I faced from paying back my student loan debt, and not even because I was a southern boy thrust into the big city (NYC). But because, as ashamed as I am to admit it, I couldn't intubate. However, after spending four long weeks in the operating room (OR), that was no longer the case. Actively involved with EMS, I decided to write this article to assist you in intubating and avoiding the stress I faced my first week of airway exploration.
What the anesthesiologists will tell you is: Open the mouth. If you're using the Macintosh (curved) blade, sweep the tongue out of the way, stick the tip of the blade into the vallecula, lift the structures up and toward the far corner of the room, visualize the cords and stick the tube between the cords (seeFigure 1 at the top of the page).
What you'll actually do is: Open the mouth, stick the blade in, lift up and not see a darn thing except a bunch of useless, confusing, pink tissue. In my case, I thought,Maybe I should lift harder. So you'll strain and strain and strain, giving some poor patient a whopping soar throat and not end up any closer to the cords.
The anesthesiologist will also say, ˙All right, come out.Ó He'll take one peek and snake it down there while you stand around like an idiot (and the surgeon might even say something like, ˙What an idiot!Ó).
It's incredibly frustrating because once you look at the interior of a patient's airway, you don't know whether to go deeper, go shallower, go left or right, lift more, lift less, or apply cricoid pressure. As a beginner, you don't have a clue because you can't see anything but pink mush.
So remember this first intubation pearl: Your initial goal isn't to find the cords. It's to find the epiglottis. If you insert the blade extremely slowly into the mouth (about 1 cm at a time), the progression will be tongue, tongue, tongue, tongue, tongue, tip of the epiglottis.
This intentionally slow blade insertion technique gives you the best opportunity to slip the blade into the vallecula, because if you insert the blade too rapidly and pass the vallecula by even just 1.0Ï1.5 cm (which I did around a dozen times), you'll be looking into the esophagus and not the trachea!
If all you see is pink mush that's not tongue, pull back. Everyone knows what the tongue looks like, and the epiglottis is obviously the epiglottis. So, the only mushy thing in there is the esophagus (and technically the posterior pharynx, but if you're deep enough to no longer be seeing the tongue, yet shallow enough that you can still see the posterior pharynx, the epiglottis will also be in view in all but the most anatomically challenging intubations).
If you pass the epiglottis, you're looking at either the trachea -- which is obvious because it has vocal cords that are white and is a big open cave (since the tracheal rings don't collapse) -- or you've snuck the tip of the blade into the esophagus. And keep in mind that as soon as you lift up the esophagus, it opens up as big as the trachea and looks a lot like a trachea without vocal cords.
GETTING THE PESKY TONGUE OUT OF THE WAY
When using a Miller (straight) blade, if the tongue is flopping in your view, just shift the blade a little to the right of the tongue’s midline. That will pop the tongue over to your left and out of the way. With the Macintosh blade, if you can get the mouth open wide enough, insert the blade on the very far right side of the patient’s mouth, turning the handle of the blade 90º so the handle is almost pointing toward their left ear. Then, advance it just about to the depth of the epiglottis and rotate it back to the normal position (perpendicular to the teeth and pointing toward the far corner of the room). This technique will pack the tongue over like a can of sardines.
HOW TO MAKE YOURSELF A LIAR
Now, here’s what you should not do: Take the blade of the laryngoscope, preferably a Miller blade, insert it past the tongue, past the epiglottis and into the esophagus. Look. See nothing. Lift up as hard as you can, and strain until blood vessels are bursting in your head. The esophagus will usually lift around the blade and the sides will slope down in the same exact shape as the vocal cords. The anesthesiologist will ask, “Do you see the cords?” You’ll say, “Yes, I do.” You’ll pass the tube between the two sides of the esophagus, and you’ll inflate the stomach as soon as you ventilate the patient. The anesthesiologist’s response will usually fit one of the following patterns:
A) They’ll shove you away, yank out the tube, bag them a couple of times and pass the tube themselves. (This occurs about 90% of the time.)
B) They’ll freak out, yell at you, hurt your feelings and say something like, “I don’t care if you can’t see anything, but don’t lie and say you see the cords if you don’t.” You’ll say something witty (like I did, which was “B-bb- b”) and then stumble away dazed.
C) Or, and you must always be ready for this: They’ll stare at you with a blank look, and say nothing. They’ll wait for you to realize you’ve screwed up and make you remove the tube and begin bagging the patient again. Do this quickly. You’re the one in charge. Trust no one to do it for you.
ARE YOU IN?
When learning to intubate in the blessed quiet of the OR, it may appear all you need to confirm that you’re in the trachea is your handy stethoscope. After all, as soon as you pass the tube, you listen to each lung and can quickly differentiate between a perfect intubation, a right mainstem intubation or an esophageal intubation. But in the back of an ambulance or on the side of a highway with sirens going and bystanders screaming, when you’re trying to intubate through blood and vomitus, you’ll be lucky if you can hear your partner, much less breath sounds. Even if you can hear breath sounds, your ears will lie to you. If you intubate the esophagus and distend the stomach with air, the sounds of the progressively dilating stomach will be transmitted through the entire thorax with every successive bag, making it seem as if there are bilateral breath sounds. Plus, the morbidly obese or patients with pneumothoraces or emphysema won’t have any breath sounds at all, even if you’re in the trachea. By the time their pulse ox drops and clues you in that you’ve entered the esophagus, the patient’s often near arrest (possibly from the liters of air that have squeezed into their stomach). The solution, of course, is capnography. As soon as you place a tube in the trachea, CO2 will come streaming out of the tube with every exhalation. If you have a quantitative capnometer, you’ll instantaneously get a CO2 level in the 30s or 40s. If you have a qualitative capnometer (the purple cap you put on the end of the ET tube), it will switch from purple to yellow the instant you’re in the trachea, but BE CAREFUL. Your eyes can lie to you. If the patient has been bagged and some of their expired CO2 has been forced into their stomach, when you pass the ET tube into the stomach, the cap will change color as the remaining CO2 is expelled. This, however, won’t continue. With subsequent breaths, the capnometer will quickly stop changing color and fade to a dull purple. That’s your clue you’re in the stomach. Get out and start bagging again.
THE ART OF BAGGING
Bagging isn’t easy. It looks easy, and a lot of people think it’s easy, but that’s usually because they’re going through the motions but not actually getting enough air in the lungs. Bagging isn’t about pressing the mask on the face. If you don’t believe me, try this: Lie flat on your back. Take your right hand and press down on your chin, toward your chest. Now, try to breathe. If you can breathe at all, you’re lucky—and awake. But squash someone’s face down that way when they’re anesthetized and you’ll have better luck ventilating them through their stomach (which I tried and found it doesn’t work well either). The key to ventilating is to do the c-clamp technique they’ve shown you in class, but make sure you pull the chin up into the mask. Don’t press the mask down on the face. Hook the chin with one of your fingers and squeeze it up into the mask. It’s easiest to do if you put your pinkie on the angle of their jaw and pull up. The important trick here is to put your finger only on the outside of the bone, not into the soft tissue under the chin. (Try it on yourself. You can’t breathe with someone pushing inward on the soft tissue under your chin.)
The approach to intubation I learned during my month-long training is: 1.Walk down the tongue 1 cm at a time until I saw the epiglottis (with the Mac). If I looked inside and saw nothing but pink, I pulled out and went back in again slowly. 2.When I visualized the epiglottis, I slid the blade into the vallecula then lifted up and forward. If I couldn’t see the cords at this point, I would extend the patient’s head slightly, which brought the larynx into view nine out of 10 times. 3.If I still couldn’t see the vocal cords, I would ask for thyroid or cricoid pressure. If I couldn’t see the cords after posterior pressure was applied, I would lift hard toward the far corner of the room. If I still couldn’t see the cords at this point in my intubation attempts, I would say, “They’re very anterior,” (an anesthesiology catch-all phrase) and give the anesthesiologist the scope.
During difficult-to-intubate cases, I’ve seen skilled anesthesiologists intubate an esophagus, lacerate lips and chip teeth. So be careful. Be very careful whenever you attempt to intubate a patient, realizing that even when the experts do it, intubation isn’t a benign procedure and complications—cosmetic and otherwise—can occur. If you perform each of these tips discussed and still can’t see the vocal cords, your patient is justifiably a “hard tube,” and you need to have someone else attempt to intubate them, or try another rescue airway. JEMS
Graham E. Snyder, MD, is the medical director of the WakeMed Health and Hospitals Medical Simulation Center and the associate program director of the UNC Emergency Medicine Residency. Contact him at firstname.lastname@example.org.