EMS Airway Clinic

Recently, I came across a destitute colleague who had just responded to a code for a cardiac arrest. During the arrest, the patient was intubated successfully, without interruption of compressions. I was puzzled. Why was my colleague distressed? Surely, she had done her job well, securing the airway in a prompt and efficient manner.

As it turns out, another provider had questioned numerous elements of her care. First, the other provider debated whether to give a paralytic. The other provider vehemently argued that a paralytic was indicated to “best optimize the chance of success.” My colleague did not feel that a paralytic was indicated in cardiac arrest, and intubated without the use of any additional medications.

After the argument about the paralytic, the other provider then had the nerve to question whether the patient should have even been intubated at all! In point of fact, intubation in cardiac arrest is quite controversial, and my downtrodden colleague had every right to feel frustrated.

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Although endotracheal intubation has long been regarded as the “gold standard” for cardiac arrest, recent guidelines de-emphasize the procedure, especially if intubation is to be achieved at the expense of other evidence-based interventions (i.e., CPR and electrical therapy) associated with improved survival and better neurological outcomes.(1,2)

Now I will admit that when I first read this recommendation, it was difficult to digest. As a paramedic, anesthesiologist, and intensivist, I’ve never thought twice about securing an airway with an endotracheal tube during a cardiac arrest. Historically, to do otherwise would be considered malpractice! However, when one examines the recent literature, it is understandable why intubation for cardiac arrest remains a provocative topic. For starters, the reader is referred to a comprehensive and well-written review on this topic by Dr. J.V. Nable et al.(1)

Intubation has not been shown to positively impact outcomes for cardiac arrest patients, and there are several explanations for this somewhat counterintuitive finding.

First, intubation during cardiac arrest is not always straightforward, and in at least one study, 30% of patients required more than one attempt.(3)

Second, the learning curve to attain competence is steep—one study suggests up to 60 intubations are required to become proficient—and in some systems, EMS providers do not have opportunities maintain this skill.(4) As Nable et al write, “maintaining proficiency in endotracheal intubation is a significant barrier for many prehospital providers.”(1) In Wang et al, intubation success by medics was only 78%.(3)

Third, intubation is followed by positive pressure ventilation (PPV), and PPV has been shown to decrease preload, lower cardiac output, and negatively impact the effectiveness of chest compressions.(1)

Fourth, intubation may require interruption of chest compressions, and this has clearly been linked with worse outcomes.(5) For the abovementioned reasons, in some countries, such as the U.K., a case has been made for abandoning intubation altogether in cardiac arrest.(6)

Coming back to my colleague’s dilemma regarding paralysis for intubation in cardiac arrest, this is also a contentious topic. On one hand, paralysis may enhance intubating conditions and facilitate prompt control of the airway, thereby avoiding airway trauma with multiple laryngoscopic attempts, and preventing aspiration. Moreover, the most feared complication of paralysis—the “can’t intubate, can’t ventilate” scenario—is relatively rare. In one study of more than 6,000 trauma patients at our institution (University of Maryland R Adams Cowley Shock Trauma Center in Baltimore), only four patients required a surgical airway.(7)

On the other hand, the hazards of positive pressure ventilation, hyperkalemia associated with succinylcholine, and the rare instance of failed intubation in a paralyzed patient with a difficult airway, all pose an unacceptable risk/benefit in cardiac arrest. The decision to use paralytics is as difficult as deciding to intubate in cardiac arrest, and the use of these agents can only be recommended for the most highly trained providers.

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What about supraglottic airways? This class of airways includes the laryngeal mask airway (LMA), Combitube, laryngeal tube and other various proprietary devices. Although these devices do not represent a “definitive airway,” several studies have shown equivalent outcomes when these devices were compared to endotracheal intubation in cardiac arrest.(1,8) Supraglottic airways have several advantages over intubation. Learning curves are easier, the devices can be placed faster, and there may be fewer complications during device insertion.(9)

To date, no one device has been shown to be conclusively superior to another. Patients eligible for placement of a supraglottic airway require adequate mouth opening, no underlying severe lung disease (i.e., decreased lung compliance), and low risk for aspiration.(1)

At the end of the day, airway management for cardiac arrest may be achieved according to the proficiency and resources available to the provider. EMS providers should not be discouraged by the literature! Airway management is still important. In one study by Wong et al, the best short-term survival was seen in patients who had an advanced airway placed within five minutes of the arrest.(10)

Other studies have failed to show any difference between intubation and use of bag-valve mask ventilation (BVM).(11) However the airway is managed, current recommendations still emphasize the importance of providing ventilatory support during cardiac arrest.(2) In jurisdictions where intubation is used for cardiac arrest, providers should perform the procedure with “sufficient frequency to maintain competence within a highly managed system that actively monitors success rates, complications and patient outcomes.”(9)

If intubation is to be considered in cardiac arrest, it should only be attempted if:

• The provider is proficient;
• There are no interruptions in chest compressions; and
• The attempt takes no more than 10 seconds.(2)

Survivors of cardiac arrest who require intensive care management will usually require definitive airway management with endotracheal intubation at some point, but early in the arrest, providers should focus on providing high-quality CPR.(12)

References
1. Nable JV, Lawner BJ, Stephens CT. Airway management in cardiac arrest. Emerg Med Clin N Am. 2012;30:77–90.

2. Neumar RW, Otto CW, Link MS. Part 8: Adult advanced cardiac life support: 2010 American Heart Association guidelines for cardiopulmonary resuscitation. Circulation. 2010;1222(183):S727–S767.

3. Wang HE, Yealy DM. How many attempts are required to accomplish out-of-hospital endotracheal intubation? Acad Emerg Med. 2006;13:373–377.

4. West MR, Jonas MM, Adams AP, et al. A new tracheal tube for difficult intubation. Br J Anaesth. 1996;76:673–679.

5. Kellum MJ, Kennedy KW, Ewy GA. Cardiocerebral resuscitation improves survival of patients with out-of-hospital cardiac arrest. Am J Med. 2006;119:335–340.

6. Deakin CD, Clarke T, Nolan J. A critical reassessment of ambulance service airway management in prehospital care: Joint Royal Colleges Ambulance Liaison Committee Airway Working Group. Emerg Med J. 2008;27:226–233.

7. Stephens CT, Kahntroff S, Dutton RP. The success of emergency endotracheal intubation in trauma patients: A 10-year experience at a major trauma center. Anesth Analg. 2009;109:866–872.

8. Kajino K, Iwami T, Ktamura T, et al. Comparison of supraglottic airway verus endotracheal intubation for the pre-hospital treatment of out-of-hospital cardiac arrest. Critical Care. 2011;15:R236.

9. Thomas MJC. Prehospital intubation in cardiac arrest: The debate continues. Resuscitation. 2011;82:367-368.

10. Wong ML, Carey S, Mader TJ, et al. Time to invasive airway placement and resuscitation outcomes after inhospital cardiopulmonary arrest. Resuscitation. 2010;81:182–186.

11. Shin SS, Ahn KO, Song KJ, et al. Out-of-hospital airway managemetn and cardiac arrest outcomes: A propensity score matched analysis. Resuscitation. 2011. Accessed 18 Feb 2012.

12. Morley PT. The key to advanced airways during cardiac arrest: Well trained and early. Critical Care. 2012;16:104.

Review of: Wang HE, Simeone SJ, Weaver MD, et al. Interruptions in cardiopulmonary resuscitation from paramedic endotracheal intubation. Ann of Emerg Med. 2009:54(5):645-652.

The Science
Emergency guidelines have started emphasizing continuous uninterrupted chest compressions for the treatment of cardiac arrests. Traditionally, paramedics in the U.S. almost always perform endotracheal intubation (ETI) on cardiac arrest patients. The authors of this study examined interruptions in chest compressions due to paramedic ETIs using data from the ROC study. They defined an interruption as greater than five seconds. They excluded the period of interruptions related to rhythm analysis. Of 182 arrests, 100 cardiac arrests were analyzed and found. They also found the following:

Median number of interruptions for ETI per cardiac arrest: 2 with a range of 1-9.
Median time for first ETI associated CPR interruption: 46.5 seconds with a range of 7-221 seconds.
Median time for second and subsequent intubations associated CPRF interruption: 35 seconds with a range of 21 to 58 seconds.
Average number of intubation attempts was two2 with a range of 1 to 9
Median total for all endotracheal intubations: 109.5 seconds.
This total interruption time did not change significantly when interruptions where defined as 10 seconds but decreased slightly (102 seconds) when interruptions were defined as 20 seconds.
ETI accounted for 22.8% of all CPR interruptions.

The authors conclude ETI by U.S. paramedics accounts for a significant amount of interruptions, as well as prolonged interruptions.

The Street
The authors find the results of this study on the role of intubation in prehospital airway management of cardiac arrest patients to be eyebrow-raising, but for different reasons.

Medic Marshall: I have to admit that I’m not one to jump to the laryngoscope and ET tube to manage someone’s airway. But I find this research disturbing and appalling. The statistics speak for themselves. I find them staggering. Nine intubations attempts? Or almost four minutes to intubate a patient? This is exactly why I’m a strong proponent for alternative airways, such as the King LT or Combitube. They are faster and more efficient, and can still secure the airway while minimizing interruptions. Best of all though, they can still be used with an impedance threshold device, such as the ResQPOD.

Again I feel the need to re-iterate that I m not against paramedics intubating in the field, just that it is really hard to justify when you have research like this. If your system is capable of giving their providers the experience and education to intubate proficiently, then by all means I think you should; I also think excellent clinical judgment needs to be used as well though know when to tube or not to tube.

Doc Wesley: I congratulate Dr. Wang and his colleagues for providing us even more compelling reasons to not perform ETI in the cardiac arrest victim. Research clearly shows that interruptions in chest compression greater than 10 seconds results in a significant decrease in coronary perfusion. This loss occurs not from the interruption alone but from the fact that it takes at least 30 seconds of chest compression to “re-prime” the heart.

Although many will scoff at the apparently long interruptions and multiple intubation attempts and say, “this could not happen in my system,” to them I say, “you are wrong.” This study was from multiple high-performance systems with excellent medical oversight and quality improvement.

Regions Hospital in St. Paul will soon be publishing their data, which shows that they were able to insert the King LT within one minute of patient contact without chest compression interruptions.

While there may be value for prehospital endotracheal intubation, the evidence is growing daily that for victims of cardiac arrest and multiple trauma, alternative airways used with appropriate monitoring may be more beneficial and avoid significant complications.

The goal now is to further reduce the chest compression interruptions with faster rhythm analysis and defibrillation.

We were on a tactical-EMS (TEMS) operation in February in the mountains of western Maryland. Several of us lamented, whined actually, about the cold, wet weather. Our TEMS team leader, Mark Gibbons, set us straight, “There’s no such thing as bad weather, just those ill prepared for current conditions.”

My friend’s statement easily applies to most difficulties we encounter in life. Tasks that we find troublesome are usually hard to manage because we are unprepared or conditions are unexpected. The same applies to airways we label as difficult.

In previous articles on airway anatomy, I discussed how understanding the anatomy helps us make better decisions and improves our level of success. The same paradigm applies to a “difficult airway.” As medical practitioners, the more clearly we understand why an airway is difficult, the less difficult it becomes to manage.

From Difficult to Everyday
Although there’s little you can do about your patient’s anatomy and physiologic condition, you still have to deal with it. I used to believe that I chose the laryngoscope blade for my patient. I was wrong; the patient picks the blade. I had to learn to perform a good patient assessment and really understand my patient’s needs. A good assessment only takes about a minute or so, but it’s a lot more than just glancing at the patient’s face. How far can you open the patient’s mouth? What’s the length of the jaw? Is the neck mobile? A short neck, short jaw and receding mandible calls for a straight blade, not a 3 Mac just because I like a curved blade. If you don’t listen to your patient, you’ll create a difficult airway.

Another thing we can’t change is our working environment. How many times have you used the “belly flop” intubation position on the floor? Sure, you can always move the patient from the bathroom to the living room, but it’s still a tough place to work. If you want to turn a tough position into a difficult airway, then never prepare yourself to work in that environment. The Maryland State Police Department runs a program called the Airway Rodeo. The final session is a scenario-based competition between teams. We place manikins in every position you can imagine: secured to a backboard, sitting up, even duct-taped to the underside of a table. The idea is to challenge our students to intubate in the most awkward, absurd positions we can envision so when they’re faced with something similar in the field, the patient position doesn’t make the situation a difficult airway.

Training and experience are two factors that can turn a difficult airway into just another day at the office. Of course, it works the other way too. The great part is that you have complete control over both of these factors. There’s always time to train. Commit just 30 minutes a day to your profession. Read an article. Listen to a podcast. Review a peer’s patient care report. Talk to someone who’s been there, done that. Case reviews and scenario-based training are the best way to become experienced before you’re faced with a real patient. Don’t let a lack of training and experience create a difficult airway situation.

For the past 10 years, Dr. Richard Dutton, trauma anesthesiologist at the R Adams Cowley Shock Trauma Center, has been a mentor and friend. His view on equipment has made a huge impression on me. Our equipment should be simple, we have to know how to use our tools, and our equipment must be readily at hand. Now, I’m a big widget guy. But we all know the chances of something actually working in an emergency is inversely proportional to the number of moving parts. It’s OK to have an airway gadget with a lot of parts as long as you’re prepared for them to fail and you’re prepared to deal with it. Know your equipment and have it with you. As Dr. Dutton is fond of saying, “If it’s not within three feet of you, it may as well be on Mars.” You’re a professional; don’t allow equipment issues to create a difficult airway situation.

Conclusion
Failing to have a plan, failing to understand a plan and failing to follow a plan have led many a good medical professional down long, torturous roads. My gosh, folks! We’ve got more algorithms than I can count, so I know you’ve got one for managing a patient’s airway. Know it and use it. Airway management, and especially endotracheal intubation, is a high-consequence therapy. Your plan should be simple to follow, flexible and well practiced. At a minimum, it should provide strategies based on patient assessment, environmental conditions, distance to a hospital and available equipment. A task force of the American Society of Anesthesiologists recognized this in 1992 and said it best in their 2002 update, “ … the use of specific strategies facilitates the intubation of the difficult airway.”(1) Don’t create a difficult airway by failing to plan.

Situational awareness is the proper alignment of your perception of reality with reality.(2) In one study, the U.S. Coast Guard found the lack of situational awareness accounted for 54% of medium- and high-severity towing vessel incidents.(3) Every profession has a book full of examples of adverse incidents that occurred because of poor situational awareness. Airway management is no different.

I arrived as the second paramedic at motor vehicle crash. The patient was in the ambulance, so I hopped in the side door. I saw a used endotracheal tube on the floor, a bloody laryngoscope blade and the crew bagging the patient. I heard them say, “He’s clinched. You need to RSI him.” I started my assessment and found the patient’s “clinched jaw” was held securely in place with a tight-fitting cervical collar. Nonchalantly, I opened the front of the cervical collar and found a non-clinched, highly mobile jaw. What was a difficult airway turned out to be a case of poor situational awareness.

Those of you who have sat in on my lectures know I don’t think difficult airways are as common or as bad as we’re sometimes led to believe. I think that, for the most part, we control our destiny. Although you can’t control a patient’s anatomy or some of the situations in which we work, you’re at the helm in regards to training, experience, equipment, strategies and situational awareness. If I may be so bold as to modify Mark Gibbons’ quote, I would say, “there are no difficult airways, only providers ill prepared for current conditions.”

Be safe my friends.
charlie

References
1. American Society of Anethesiologists. Practice guidelines for management of the difficult airway: An updated report by the american society of anesthesiologists task force on management of the difficult airway. Anesthesiology. 2003; 98:1269–1277.
2. Personal communication with Commander Curtis Ott, USCG (ret). June 2008.
3. Crew Endurance Management, USCG, 2008, p 1

By David Zarker, EMT-P

Recently, I attended a seminar where the keynote speaker recommended endotracheal intubation be abandoned as a prehospital skill. A great deal of discussion ensued, mostly regarding the complications and legal liability of failed intubations and misplaced tubes, as well as the implication of new adjuncts to replace intubation.

Although I believe we’ve seen great improvements in airway adjuncts in the past several years, they’ve all had limitations and complications, and oral tracheal intubation has remained the “gold standard” for airway control and maintenance. Thus, rather than discontinue this life-saving procedure, we should attempt to figure out why it’s problematic in the prehospital setting and develop ways to improve its success.

As an EMS supervisor, part of my job is to administer our agency’s quality assurance program. Because our department uses rapid sequence induction (RSI), failure to secure an airway isn’t an option, and this intervention is monitored closely. In November 2006, my colleagues and I noticed an increase in unsuccessful intubations and a series of multiple intubation attempts. We monitored this for several months to ensure we were seeing an actual trend and not just a “bad month.” In February 2007, we determined it was a trend, and we set out to resolve the problem.

Not only is it imperative to secure an airway, it must be accomplished with a minimal number of attempts. A 2004 study showed an increase in complications following the second attempt at oral tracheal intubation.1 The study reported that hypoxemia occurred in only 11.8% of patients intubated within two attempts; however, hypoxemia was seen in 70% of patients on whom more than two attempts were made. Aspiration went from 0.8% within two attempts to 13% after more than two attempts, and bradycardia occurred in only 1.6% of twice-attempted intubation patients versus 21% for patients undergoing more attempts.

Our department was on track with these complications, and we needed a solution.

A New Way
In March 2007, several members of Martin County (Fla.) Fire Rescue, attended the EMS Today conference, where we were introduced to the GlideScope® Ranger. I arranged to have a representative present the Ranger to our department for a more in-depth evaluation.

A regional sales rep brought a unit to our training office and we had several of our rescue lieutenants (EMS supervisors) and paramedics use the unit to intubate our training mannequins. Intubation with the Ranger is slightly different than what paramedics are used to. So there was a small learning curve, but after 10–15 minutes of practice, everyone was comfortable with the equipment and able to intubate effortlessly. We easily intubated the difficult airway head and a mannequin with a cervical collar in place. In all cases, we were able to intubate on the first attempt and in an acceptable timeframe.

Because it was the middle of our budget year, it took some juggling of funds, but by fall 2007 we were able to purchase four Rangers. We weren’t able to purchase enough units for every ALS truck, so we decided to place one on each of the rescue lieutenant’s vehicles and one on our medical helicopter. Rescue lieutenants and flight medics are the only ones who perform RSI and they respond to most of the critical calls. With this strategy, we felt the Rangers would be quickly available anywhere in the county.

Case Study #1
Early one morning, one of our stations responded to a motor vehicle crash (MVC) in which a motorcycle struck a pickup truck broadside at a high speed. The driver of the motorcycle was lying approximately 75 feet from the point of impact and was unconscious and unresponsive. No helmet had been worn (they’re optional in Florida) at the time of the accident.

Physical assessment revealed unequal pupils and blood in the patient’s ears, nose and mouth. He had shallow respirations at four to six a minute and uneven chest rise. Examination of the extremities revealed bilateral femur fractures. His other vital signs were: Pulse 130, weak and regular; blood pressure 88/54; and SaO2 86.

Initial treatment included manual C-spine stabilization while crew members attempted to assist ventilations with bag-mask ventilations (BMV). Because his jaw was clenched, the ventilations were ineffective. It was obvious that if the patient was to have any chance of survival, an airway needed to be secured quickly. Due to the severe head injury and the clenched jaw, few options were available.

The crew decided to perform RSI and orally intubate the patient. The patient was sedated and paralyzed, and oral tracheal intubation was attempted. The first attempt was unsuccessful, and the patient’s pulse dropped to 52. The patient was then ventilated by BMV, bringing his pulse back to 120.

A rescue lieutenant arrived on scene with a video laryngoscope, and the patient was successfully intubated on the first attempt. The patient was air lifted to the local trauma center, and after several months of recovery, he was released to a rehabilitation facility to undergo physical therapy. A full recovery is expected.

Case Study #2
Whenever a difficult airway is mentioned, we naturally think of trauma patients, but some of the most challenging airway problems can arise from medical calls. Recently, one of our rescue crews responded to an “unknown medical” in a mobile home park. On arrival, they found an extremely obese woman in her 50s in the back bedroom of a small mobile home and in severe respiratory distress. An initial exam revealed her skin to be pale and diaphoretic, and rales were noted in all lung fields. Her pulse was 140, BP was 74/48, SaO2 was 54%, and respirations were six a minute, with cyanosis noted around her lips.

CPAP was attempted but discontinued within a few minutes because the patient was too weak and tired. Respirations were assisted with BMV while an IV was established. Lasix 80 mg was administered, but morphine and nitroglycerine were withheld due to her hypotension.

A second IV was established, and a dopamine drip was started with the hope of increasing her BP enough to allow for the administration of additional medications.

The patient’s condition continued to deteriorate, and an attempt at nasal intubation proved unsuccessful. A supervisor dispatched on the call decided, in conjunction with the scene paramedic, to use RSI and attempt to orally intubate the patient. The crews realized it would be a difficult intubation, but the patient needed an airway, and with video laryngoscopy available, team members felt confident they would be successful. The patient was paralyzed and successfully intubated using the Ranger on the first attempt.

Other Cases & Impressions
Our crews have also used the video laryngoscope successfully to clear airway obstructions in two children. Visualization was quick, and the design of the blade allowed more room in the mouth to maneuver the Magill forceps.

In instances when a supervisor arrives on scene where a patient has already been intubated, but the crew is unsure if the placement is correct, we have used the Ranger to quickly and easily verify tube placement by inserting the blade/camera into the airway. Within a few seconds, several providers at once can confirm placement on the video screen. Our flight medics also frequently use this technique to verify tube placement before loading intubated patients into the helicopter.

Many of our paramedics have said they also prefer the Ranger over traditional methods because they don’t have to put their face down by the patient’s. This decreases the possibility of bloodborne exposure from secretions or blood coughed up by a trauma patient.

After we put the Rangers in service, we took them to local emergency departments for demonstrations. The physicians were impressed, and on several subsequent occasions, called for a rescue lieutenant when they had a difficult intubation and an anesthesiologist wasn’t available.

During the past nine months, we’ve used video laryngoscopy on 72 prehospital patients and successfully intubated all but one. When I performed a quality assurance review on the failed intubation, I determined it was most likely due to an inexperienced operator error. After that case, our rescue lieutenants provided refresher training for all crews, and the problem hasn’t happened since.

Getting Started
I can’t stress enough the importance of training for anyone who may have the opportunity to use this equipment. The procedure isn’t difficult; it’s just different than the way paramedics were originally trained to intubate with a traditional laryngoscope. The design and shape of the blades actually make intubation easier and require much less force to visualize the vocal cords. However, if you aren’t comfortable with the equipment, you can feel awkward during your initial attempts.

I recently had a discussion with a physician who was concerned that paramedics may become too reliant on the Ranger and felt it could reduce their ability to intubate the “traditional way” if the device was unavailable. I definitely understand this concern, especially if every ALS unit carries a video laryngoscope, but in our service we expect paramedics to attempt to secure the airway with their available equipment and not wait for a rescue lieutenant to arrive with a Ranger.

To date, we haven’t had an intubation attempt delayed and the paramedics haven’t exhibited any decline in traditional laryngoscopy skills. A strong quality assurance program should keep this from happening.

Although the controversy over prehospital oral tracheal intubation still rages, I believe the endotracheal tube is the best and most secure airway available. I’m not recommending that every ALS unit carry a video laryngoscope, but I strongly urge departments, especially those using RSI, to find a way—through grants, private donations or fundraisers—to obtain units and place them strategically within their service area. The results of your efforts, in terms of improved patient care, will be priceless.

David Zarker, EMT-P is a rescue lieutenant with Martin County (Fla.) Fire Rescue. He previously served as the program coordinator for LifeStar, Martin County’s air medical program, and was involved in creating a public/private partnership in order to bring an affordable air medical program to Martin County. He’s also active in protocol development, research and development.

References
1. Mort T: “Emergency tracheal intubation: Complications associated with repeated laryngoscopic attempts.” Anesthesia & Analgesia. 99:607–613, 2004.

Disclosure: The author has reported no conflicts of interest.

By Graham E. Snyder, MD

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 (see

the Figure).

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.’ 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!’).

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 Yourselve 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.)

Summary
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.

Conclusion
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 gsnyder@med.unc.edu.

When we intubate a patient, all we really want to do is place the endotracheal tube in the glottis. Let’s face it, the glottic opening can be a tough feature to locate on a good day, let alone wh

en things just aren’t going well. Blood, vomit, laryngospasms, edema; you know the drill. If you want to find the glottis, stop looking for the glottis. What? Read on, friends, I’ll show you.

Anatomy of the Larynx
The larynx is made up of three single cartilages and three pairs of cartilages.

The thyroid is the largest of the laryngeal cartilages. It’s within this cartilage that the glottis is located. The anterior ends of the vocal cords are attached to the thyroid cartilage. This feature gives us the ability to directly move the glottis to improve our view. Known by different names, external laryngeal manipulation (ELM), backward upward rightward pressure (BURP), digital physical laryngeal manipulation; the procedure of manipulating the thyroid cartilage to optimize the glottic view has been described for many years.(1–3)

The cricoid cartilage, the most inferior of the laryngeal cartilages, is the only laryngeal cartilage that’s a complete ring. In pediatric airway, the cricoid cartilage is the narrowest part of the airway. Non-cuffed tubes fit snuggly into the ring to prevent air leak. Cricoid pressure has been used to improve glottic view during laryngoscopy, but I think you will find that laryngeal manipulation does a better job of optimizing the glottic view. One of the very best studies I’ve read on the use of cricoid pressure was published in 2007. The authors concluded, “We recommend that the removal of cricoid pressure be an immediate consideration if there is any difficulty either intubating or ventilating the ED patient.”(4) As an airway professional, you owe it to yourself to read the entire study.

Let me now introduce to you, straight from the back of the tongue—the most important airway landmark, the intubator’s very best airway friend, the gateway to the glottis—THE EPIGLOTTIS!

Remember when I told you to stop looking for the glottis? I want you to start looking for the epiglottis. Remember from our last lesson that the inferior (extrinsic) tongue muscles are connected to the mandible, hyoid and epiglottis. We can use that connection to locate the epiglottis. I’ve found the epiglottis to be easier to locate on a more reliable basis for both novice and experienced providers. Sounds like a study in the making.

Try this: Insert the laryngoscope blade into the patient’s mouth and just follow the tongue posteriorly until you locate the epiglottis. Lift the epiglottis and there’s the glottic opening. Most of the time, it’s just that easy.

Posterior Cartilages
The second best friend of the intubator is the group of three pairs of cartilages, which lie along the posterior border of the glottic opening; the corniculate, cunneiform and aryetnoid cartilages. The arytenoids sit on top of the posterior portion of the cricoid cartilage. The posterior end of each vocal cord is attached to an arytenoid cartilage. The length and medial-lateral positioning of the vocal cords are accomplished by movements of the arytenoids. The arytenoids can’t be seen in the standard laryngospic view because they’re buried in tissue.

The corniculates sit on top of the arytenoids and are seen during laryngoscopy immediately lateral to the interarytenoid notch. The cureiform are embedded in the aryepiglottic folds. They give support to these membranes, which connect the arytenoids to the epiglottis. In the standard laryngoscopic view, the cuneiform can be seen immediately lateral to each of the corniculates.

Collectively these cartilages go by a variety of names: the arytenoids, posterior cartilages, nodes. Regardless of which term you use, know that they are the posterior border of the opening to the glottis and are identified by a notch in the middle and two pairs of bumps on either side.

Conclusion
So there you are. Your new best intubation buddy is the epiglottis, and your second best buddy, the posterior cartilages. I find it ironic that these most helpful features lay right behind our nemesis, the tongue. A good knowledge of the airway anatomy is really a roadmap to success. Bust open that A&P book that you’ve got shoved up there on the shelf. It will make you a better provider.

Take care and be safe.
Charlie

References
1. Benumof JL & Cooper SD. Qualitative improvement in laryngoscopic view by optimal external laryngeal manipulation. J Clin Anesth. 1996;8(2):136–140.
2. Knill RL. Difficult laryngoscopy made easy with a “BURP.” Can J Anaesth.1993;40(3):279–282.
3. Levitan RM, Mickler & Hollander JE. Bimanual laryngoscopy: A videographic study of external laryngeal manipulation by novice intubators. Ann Emerg Med. 2002;40(1):30–37.
4. Ellis DY, Harris T & Zideman D. Cricoid pressure in emergency department rapid sequence tracheal intubations: a risk-benefit analysis. Ann of Emer Med. 2007;50(6): 653–665

Watch a video of Charlie explaining how to visualize the glottis.

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Welcome to the first edition of the “EMS Airway Clinic.” I’m Charlie Eisele, your host, guide and pathfinder through the world of prehospital airway medicine. We created this site to do one thing: provide patients with the best care possible. We’ll do just that by targeting the folks who directly impact patient care: educators, medical directors, and street level, mud on your boots, stretcher carrying EMS providers. It doesn’t matter your level of training or how many letters you have after your name, you will leave this site with stuff you can put to use immediately.

When the title came across my desk, I just had to ask, “What the heck is an airway clinic?” Prince.edu gave me a couple of answers:

1. A medical establishment run by a group of medical specialists;
2. A meeting for diagnosis of problems and instruction or remedial work in a particular activity;
3. A health-care facility for outpatient care; and
4. A musical clinic is an informal meeting with a guest musician, where a small-to-medium sized audience questions the musician’s styles and techniques and also how to improve their own skill.

I immediately threw out the first and third. Number two has merit, but I really like number four. EMS Airway Clinic is an informal meeting with guests to provide a variety of styles and techniques to improve our skills.

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Here you’ll see articles, videos, podcasts and a variety of other vehicles to share best practices in airway management. I really like case studies. They’re a great way to gain experience without having to make mistakes yourself. Sometimes, you just want to know how something works, so there will be “how to” items. We will provide timely news stories that impact EMS airway management and previously published articles to download, and we’ll keep you up-to-date on relevant studies and journal articles.

Here’s a preview of upcoming topics:

• The Glottis Is Not Your Friend
• Quotes from My Airway Heroes
• Video Interview with Dr. Jack Pacey
• Roadmap to the Larynx
• Sun Tzu: The Art of Airway Management

My vision is that this site be reader driven, so tell me what you want. What topics interest you? What tools and techniques have you found successful? I know you’ve got case studies and war stories; let’s hear them.

I’m a huge fan of professional, open discussions, so expect me to weigh in on controversial topics. Say, something like “should we intubate?”

Related Link

• Should We Intubate?

Did you make it to the 2011 EMS Today Conference & Exposition? What a great experience! I had the honor to moderate a panel discussion titled “Should We Intubate?” Four great panelists and about 200 folks in the audience resulted in lively debates and a challenge to be great EMS providers. As the moderator, I really didn’t get the chance to stand on my soapbox, so I’ll take that opportunity now.

Why does the thought of taking endotracheal intubation out of the hands of paramedics invoke such a visceral response? I didn’t whine when the EOA left. No heartburn when I put MAST back on the shelf. What is it about an ET tube? Because for decades, it’s all we had.

Endotracheal intubation via direct laryngoscopy has been used since the late 1800s.¹ Numerous BLS airways were developed during World War II. Extraglottic airways appeared in our airway kits in the early 1980s.² Flexible and rigid fiber optic laryngoscopes made their way into operating rooms in the early 1990s. It wasn’t until the turn of the century that laryngoscopy changed for EMS with the development of video laryngoscopes.

For about 110 years, direct laryngoscopy has been THE method to place an endotracheal tube. In EMS, we’ve relied on this method for about 40 years (depending on how you write the timeline). We reinforce the dogma that the endotracheal tube is the airway of choice by referring to all other devices as “rescue airways.”

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So I ask the question: Should we intubate? When it’s appropriate, absolutely. The endotracheal tube is a wonderful tool that has been successfully placed and managed for decades outside of the operating room. It continues to be used successfully by EMS professionals on a daily basis.

I’ve read a ream of studies professing the evils of prehospital endotracheal intubation. While there are descriptions of hypoxemia and trauma during endotracheal tube placement, the vast majority of the described evils come from what is done after the tube is placed; hyperventilation, hypocarbia, unrecognized misplaced tubes and reduction of blood return to central circulation.

Wait a minute; can’t those same evils occur with extraglottic airway devices or even a bag-valve mask? Why yes, they can. You can also add gastric distention, vomiting and reduced tidal volume to the BVM list. We have to do a great job managing any airway device.

As technology has progressed, we’ve been given fantastic new tools to help us do a better job. We’ve all seen studies that show the effectiveness of end-tidal carbon dioxide monitoring to verify tube placement and appropriately ventilate. Since 2003, studies from hospital and EMS settings have published results of the use of video laryngoscopy; shorter intubation times than direct laryngoscopy, high first pass success rates, and Grade I–II views with poor neck mobility.^3-5 The gum elastic bougie, (and its plastic alternatives) is such a simple and incredibly effective tool, it should be mandatory in every airway kit. I’m quite sure you can list several other items. Proven technology must be embraced as the standard of care for our patients.

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So, I ask: Should you intubate? It’s entirely up to you. Are you willing to use the tool that best fits the patient, the conditions and your abilities? Are you willing to do what it takes to be a professional airway manager?

I’ll leave you with the challenge leveled at the end of the panel discussion. All of us must drive to excel as medical professionals, to refuse to accept mediocrity as a level of care and to simply do the very best for our patients.

I’m excited and humbled at the opportunity to provide information that will help all of us become better airway managers. I look forward to hearing from you.

Until next time, take care and be safe.

Charlie

References

1. Bailey B (1996). “Laryngoscopy and laryngoscopes–who’s first?: The forefathers/four fathers of laryngology.” The Laryngoscope. 106(8):939–943, 1996.
2. Donmichael TA. US Patent 4497318, Feb. 5, 1985.
3. Agro F, Barzoi G, Montecchia F. “Tracheal intubation using a Macintosh laryngoscope or a GlideScope in 15 patients with cervical spine immobilization.” Br J Anaesth. 90(5):705–706, 2003.
4. Nouruzi-Sedeh P, Schumann M, Groeben H. “Laryngoscopy via Macintosh blade versus GlideScope: success rate and time for endotracheal intubation in untrained medical personnel.” Anesthesiology. 110(1):32–37, 2009.
5. Cormack RS & Lehane J. “Difficult tracheal intubation in obstetrics.” Anaesthesia 39(11):1105–1111, 1984.

Glossary

EOA = Esophageal obturator airway

MAST = medical anti-shock trousers

BVM = bag-valve mask

Related Link

• EMS Airway Clinic mission statement
• The Great Intubation Debate podcast