Endotracheal intubation (ETI) is one of the mainstay tools in the paramedic’s airway toolbox. Despite the controversy regarding the need for intubation in the out-of-hospital environment, most experienced prehospital practitioners can relate a situation where basic procedures were insufficient to preserve the patient’s airway patency.
Prehospital intubation poses special challenges. In addition to accommodating the patient’s airway anatomy and body habitus, the paramedic must also deal with secretions, emesis, and poor position presentation [1]. Then there is the less-than-ideal operating environment: poor lighting (too bright or too dark), bad weather (rain, snow, heat), and cramped spaces, not to mention patients that routinely present on the floor.
Optimizing first time pass rates
Despite the unique challenges of ETI in an out-of-operating room environment, there are several key points to keep in mind that can increase the likelihood of “first pass” success rates.
1. Practice ETI early, often
ETI is a perishable skill; given that paramedics may only intubate as rarely as once a year [2], ongoing preparation and practice is essential. Intubation is analogous to a situation where a law enforcement officer who, in an entire career, may never have to discharge his or her service weapon. Yet, if the situation arises, the officer must be accurate. To accomplish this, officers must pass a range test at least once or twice a year.
2. Confirm the need for endotracheal intubation
Given how little data there is for the efficacy of intubation for critical patients such as cardiac arrest [3,2] and traumatic brain injury [4,3] the paramedic must be absolutely certain that a low-frequency, high criticality task such as ETI is absolutely necessary for an improved outcome of the patient. If the airway cannot be managed by basic maneuvers and manual ventilations, intubation or use of a supraglottic airway becomes critical.
3. Position the patient
Paramedics hear this all the time, yet during initial skill acquisition rarely practice the technique. This may be partially due to the limitations of the airway manikins used in laboratory practice; there is a lack of padding materials available during practice, and instructors may not emphasize demonstration of the technique. Yet most experienced airway practitioners will suggest that proper positioning of the patient’s head, neck and shoulders is a major contributor to intubation success.
When done correctly, the patient’s ear lobe should be lined up with the sternal notch [CL1] . The head may need to be slightly elevated, or the shoulders may need padding to accomplish this. For very obese patients, a “blanket mountain” may need to be built quickly in order to accomplish an optimal airway position [CL2].
4. Slow and steady wins the race
Direct laryngoscopy is a deliberate technique. It is essential to identify all anatomical structures as the laryngoscopy blade is advanced toward the glottic opening. Bonus: there is less soft tissue damage if the minimal amount of force is applied with the blade.
5. Be prepared to evacuate
The airway, that is. Since emesis and other secretions commonly present in the uncontrolled airway, it would be wise to first pick up the hard suction catheter before the ET tube.
6. Get straight to the point
Remember that an endotracheal tube is curved; however, the optimal shape of the tube should be straight, with a slight, 15-25 degree bend at the tip, just proximal to the obturator cuff [CL3] . This permits a much more open view of the glottic opening when advancing the tube from the side of the mouth. Never use the blade channel as a “guide” when inserting the tube — this completely blocks the view, making the procedure a blind one.
Make your environment work for you
The out-of-hospital environment is, by definition, uncontrolled. Paramedics and EMTs are trained to “adapt and overcome” in chaotic situations. As related to ETI, there are several tips, tricks and pearls to keep in mind when the decision is made to intubate the patient. 
Proper patient position is all about location, location, location. Just because the patient presents in a certain position and location, it should not confine the paramedic’s reaction. If the paramedic is unable to visualize the airway when the patient is supine on the floor, relocate the patient to the stretcher, where a combination of padding and proper positioning of the back support may improve the ear lobe to sternal notch alignment.
Make the environment work for you, not the other way around. Quickly drop a jacket or turnout coat on the ground to help positon the patient into an intubating position. If the environment is too bright, ask someone to stand over your view, to block out the additional light. If the environment is very dark, a headlamp can help illuminate your immediate surroundings as you prepare your equipment.
Patient compartments in ambulances are notoriously cramped for ETI procedures, even in the “monster truck” configurations. The provider’s seat is often too close to the head of the gurney to allow proper positioning of the paramedic. Consider intubating the patient just before ambulance loading; sitting at the edge of the ambulance floor at the back of the compartment may place the paramedic in an optimal position as the stretcher is lifted into the “load” position.
Large amounts of emesis or bleeding can overcome even the best efforts to suction. If the source of the fluid is gastrointestinal, and your protocol allows, consider suctioning the stomach to divert the fluid away from the upper airway.
It is difficult to visualize the glottic opening of a patient with a “high anterior” airway. Some paramedics will request a second rescuer to apply mild pressure to the sides of the anterior cricoid rings to push the glottic opening into view. It may be better for the paramedic to perform this task during laryngoscopy first, so that an optimal position is achieved [CL4] . Then, have the second rescuer take over pressure so that the paramedic can advance the ET tube.
Endotracheal intubation is a difficult procedure to perform consistently well. Performing it in the out-of-hospital environment makes it that much more challenging. Following certain tips and adapting to the environment will help to improve the first time pass rate, which may improve the chances of survival of the critical patient.
References
1. Prekker ME et al. The process of prehospital airway management: challenges and solutions during paramedic endotracheal intubation. Critical Care Medicine. 2014 Jun; Vol. 42 (6), pp. 1372-8.
2. Wang HE et al. Procedural experience with out-of-hospital endotracheal intubation. Critical Care Medicine. 2005 Aug; Vol. 33 (8), pp. 1718-21.
3. Studnek JR et al. The association between prehospital endotracheal intubation attempts and survival to hospital discharge among out-of-hospital cardiac arrest patients. Academic Emergency Medicine. 2010 Sep; Vol. 17 (9), pp. 918-25
4. Karamanos E et al. Is prehospital endotracheal intubation associated with improved outcomes in isolated severe head injury? A matched cohort analysis. Prehospital And Disaster Medicine. 2014 Feb; Vol. 29 (1), pp. 32-6.
