One of our greatest strengths as EMS providers is our ability to manage the emergent patient’s airway.
There are many airway devices designed for the “crashing airway” patient, each with a specific purpose in mind.
As important as it is to know how to use each piece of equipment, it is even more critical to understand when any of these devices should be used.
Let’s look at the decision making process when selecting the appropriate airway device.
When should I be thinking of controlling an airway?
You should be thinking about airway control all of the time. Patients can have an uncanny ability to lose control of their airway at the most inopportune time, like when you take your eyes off of them for “just a minute” while writing in a chart or talking with your partner. Using part of your mind to continually evaluate the patient’s airway patency can help you prepare for unexpected crises.
Generally speaking, patients who are alert are those who can maintain their own airway patency, which is the ability to keep air flowing smoothly through the upper airways into the lungs. Nevertheless, even for those patients, circumstances can dictate that a suction device should be nearby. For example, patients experiencing a myocardial infarction are at risk for nausea and forceful vomiting.
Patients who are awake but altered are at risk for airway loss. The reflex which forces the epiglottis to close over the glottic opening to the larynx and keep it clear of solid objects during swallowing can become impaired as the patient’s level of mentation decreases.
The classic example is an intoxicated patient who may be awake, but whose reflexes are slowed due to ethanol ingestion. As the patient vomits, the epiglottis may not fully cover the opening quickly enough, causing the patient to aspirate emesis into the lungs. If the situation allows, altered patients should be transported in a lateral recumbent position, which allows for passive drainage of fluids while suction is immediately available.
Patients who are altered to the point of being able to respond only to verbal or painful stimulus are at real risk of losing airway control. In these cases, the same swallow reflex described above becomes very impaired, or is lost completely. The tongue may slide posteriorly when the patient is supine, partially or completely blocking the airway.
Which devices or techniques are available for EMS?
A chin lift or jaw thrust can correct most blocked airways. Both techniques tighten the muscle structure in the jaw, causing the tongue to pull forward and away from the back of the pharynx. Adding an oropharyngeal airway can help depress the tongue to the floor of the mouth in the unconscious patient without a gag reflex; a nasopharyngeal airway can maintain an open passageway through the soft tissue of the nasopharynx for the semiconscious patient. Proper sizing and insertion of either of these simple devices is absolutely necessary to reduce injury and maximize effectiveness.
In theory, artificially ventilating patients in respiratory failure or distress can be simply managed with a bag valve mask (BVM) device. In reality, it is a very difficult procedure to master with just one provider; the American Heart Association does not recommend one-person BVM use during cardiac arrest.1 Whenever possible, use two trained providers to provide an adequate mask seal and adequate tidal volume.
Historically, endotracheal intubation (ETI) was the mainstay of the paramedic’s advanced airway arsenal. Traditional practice dictated that ETI was the “gold standard” of airway control. While that might be true from the viewpoint that only ETI provides a patent airway directly to the tracheal, it is a difficult skill to achieve and retain competency. During the past decade, a variety of supraglottic airways have been developed to provide access to the larynx without having to intubate. They range from dual lumen (or two tube devices such as a combitube), to single lumen devices like the King airway. While there may be several devices available, they are designed to be inserted blindly into the esophagus, and seated so that the lower end is below the level of the glottic opening. Larger volume obturators or balloons are then inflated to create a seal in the esophagus, preventing emesis from entering the larynx.
For the very few, extremely difficult airways to manage from the oro- or nasopharynx – the “can’t ventilate, can’t intubate” scenario – cricothyrotomy may be the only choice. An opening in the cricothyroid membrane is made with either a large bore needle and ventilated with a high pressure oxygen delivery device, or a scalpel is used to create an opening large enough to insert an endotracheal tube directly into the trachea. Both are very low frequency, very high risk procedures.
How do I decide which device or technique to use?
The simplest answer is that basic airway management techniques trump advanced ones – most of the time. The least invasive airway device that can provide control is the best one to use. That mean we really have to think when confronted with the decision about which device to use.
If you can provide adequate ventilation and oxygenation to a patient with a good manual airway maneuver, an OPA and a good mask seal, do it!
In critical trauma cases, an advanced airway such as ETI has not been shown to improve outcomes.2 ETI during cardiac arrest probably has the effect of delaying effective chest compressions, when the procedure is performed, causing poor cerebral and coronary blood flow. ETI has also been shown to worsen outcomes for patients with acute injuries to the brain.3
There may be cases however, where you may not be able to adequately ventilate the patient with a BVM. Obesity, missing teeth, heavy facial hair, or a recessed jawline are but a few causes for an inadequate mask seal. Continuous vomiting, or active bleeding can also render a BVM useless, no matter how good a seal. Supraglottic airways may be a good option for these patients; otherwise cricothyrotomy may be indicated.
The bottom line? Assess your patient for his airway needs. Consider the wide variety of factors; beginning with how significant the potential is for airway loss. Preplan your airway progression. If the first device you choose is not effective, what will you use next? Try to stay one step ahead of your patient’s needs.
Summary
Airway management can look deceptively easy in the hands of an experienced and well trained provider. It is much more difficult than it seems. No two patients are exactly alike, and therefore one shouldn’t expect that their airway needs will be exactly the same.
Think about the devices in your airway “toolbox,” recognize when would be the best situation to use any of them, and be well prepared to use them successfully when the time comes.
References:
1) American Heart Association. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science, Part 8: Adult Advanced Cardiovascular Life Support. Circulation 2010; 122: S729-S767.
2) Stockinger ZT, McSwain NE. Prehospital endotracheal intubation for trauma does not improve survival over bag-valve-mask ventilation. J Trauma. 2004 Mar;56(3):531-6.
3) Wang HE et al. Out-of-hospital endotracheal intubation and outcome after traumatic brain injury. Ann Emerg Ed. 2004 Nov;44(5):439-50
