The Killer Traumatic Airway

 

by Wesley Rogers, FP-C, CCEMT-P

Case

You’re working on a duel paramedic ALS ambulance when you are dispatched to a Motor Vehicle Crash (MVC) involving a motorcycle. When you arrive on the scene, a witness states the motorcycle was traveling ~ 50-60 mph when it rear-ended an SUV that was stopped at a red light. The motorcyclist was wearing a protective vest but no helmet. The patient was ejected from the bike and landed approximately 40’ from the impact. As you approach the scene, you see bystanders holding what appears to be a flaccid patient on his side with blood and vomit pouring from his mouth & nose.

As you begin your treatment, you quickly roll the patient onto his back and secure his c-spine with a cervical collar, longboard and cervical immobilization devise (CID.)  The patient is then secured to ambulance stretcher and moved into the ambulance. On your initial assessment, patient’s Glasgow Coma Score (GCS) is 6 (E=1, V=2, M=3), RR=8 and you hear blood gurgling from his mouth. Your partner gets an initial set of vital signs, and you instruct Basic Life Support (BLS) to begin ventilating the patient with a Bag-Valve-Mask (BVM), while you prepare for Rapid Sequence Induction (RSI) to secure his airway. Vitals: HR=140, BP = 186/116, and SPO2 = 70%. You and your partner agree on using Ketamine and Rocuronium for the RSI and prepare for the intubation. You partner pushes the Ketamine and Rocuronium, and during the apneic oxygenation, you perform 30 seconds of deep suctioning before you insert the blade. As you place your video laryngoscope blade into his mouth, your partner states “our patient is in pulseless v-tach.” You’re unable to visualize the vocal cords, as your screen is covered in blood.  You quickly place an i-gel airway and begin chest compressions. You’re unable to achieve ROSC as you transport the patient to the closest trauma center.

As pre-hospital clinicians, we are often left with many questions to ponder, like: “How did he survive until we got there?”, “Why did he code right after we pushed our drugs?” “Was Ketamine the best choice of drugs, considering the patient was hypertensive and tachycardic?” “Should we have just loaded and go, or stayed and played to increase the patients best chance of survival?” “What could we have done differently?”

Despite what the show “Chicago Fire” has my mother believing, calls like these don’t happen to us very often. The incidence of primary airway trauma is a rare occurrence in prehospital medicine. Data shows it to be less than 1%, more specifically, 0.4% for blunt and 4.5% for penetrating injuries[2].  When coupled with head injured patients with decreased level of consciousness, 30% to 40% have partial or complete airway obstruction upon EMS arrival[3]. Overall, failure to secure a definitive airway is the most common factor related to inpatient mortality of trauma patients[4]. In blunt trauma patients, we frequently underestimate (1) the amount of blood & vomit that obstructs a patients airway, (2) the amount of soft tissue swelling and distortion in our penetrating injury patients, and, (3) how deadly hypoxia can be.

The Dangers of Pre-RSI Hypoxia

We as airway managers must understand how patients become hypoxic. The oxyhemoglobin desaturation curve (see below) is a curve that plots the proportion of hemoglobin in its saturated form on the vertical axis against the prevailing oxygen tension on the horizontal axis. This curve is an important tool for understanding how our blood carries and releases oxygen. Specifically, the oxyhemoglobin dissociation curve relates oxygen saturation (SO2) and partial pressure of oxygen in the blood (PO2), and is determined how readily hemoglobin acquires and releases oxygen molecules into the fluid that surrounds it. To put it simply, the more hypoxic we become, the faster we become hypoxic. The first known inflection point, where the curve becomes steeper, is at 93%[5]. Below 93% the patient is at risk for critical desaturation and hypoxic injury. With a SaO2 of 70%, the patient is in danger of dysrhythmias, hemodynamic decompensation, and are four times more likely to go into cardiac arrest[6]. 70% is the next inflection point, after this, the curve turns into a cliff. All of this was figured out through studies of healthy people. With every co-morbidity, (i.e. hemorrhage, sepsis, anemia, and shock, the curve becomes even steeper. This is why hypoxia is one of the “HOp killers”, as coined by Dr. Scott Weingart, Critical Care Intensivist,  blogger and podcaster in his Laryngoscope as a Murder Weapon series[7]. And here is Part 2.

 

 

Function residual capacity (FRC) is the amount of volume within the lungs at the end of expiration. One of the factors helping this is positive end-expiratory pressure (PEEP). In healthy lungs, maintaining PEEP or increasing our PEEP helps retain FRC. PEEP & FRC are what keeps us from going hypoxic between breaths, or when we hold our breath. Loss of PEEP, hemo/pneumothorax, and aspiration can reduce our FRC. PEEP and tracheal protection are provided by the vocal cords and epiglottis. When we become paralyzed we lose those protections, and lose our PEEP, allowing blood and vomit to enter the lungs, reducing our FRC and limiting our safe apnea time without desaturation. The presence of blood and vomit in the traumatic airway is another complicating factor as it significantly increases the likelihood of aspiration, and prevents adequate oxygenation and ventilation. Passive oxygenation strategies such as the use of a non-rebreather and nasal cannula will likely offer little benefit. Conversely, BVM ventilations will also have a limited impact and are likely to increase the amount of aspiration. [9]. The presence of a soiled airway greatly reduces first-pass intubation success rates, regardless of the device used. Direct laryngoscopy (DL) going from 75.8% first-pass success rate to 65.5%, and Video-Laryngoscopy (VL) going from 91.0% to 81.4%[10]. Management of contaminated airway must begin with the expectation that the degree of blood, vomit, and secretions appreciated externally represents only a fraction of what may be encountered on initiation of an RSI[11].

The patient from the opening case had severe facial trauma and obstruction; however, he was able to survive by positioning him on his side, which facilitated adequate airway clearance. This went away when this patient was placed supine on a backboard. Due to this position, he was then unable to be adequately oxygenated and ventilate despite attempts with a BVM. When the paralytic took effect, he lost his PEEP, whatever sympathetic tone he had left, and what little FRC he had, causing a rapid desaturation and cardiac arrest. What some would label a traumatic arrest was a hypoxic arrest. This patient did not die from exsanguination; he died because of failure to oxygenate.

 

Oxygenation Strategies for the Critical Airway

 

 

Figuring out how to oxygenate patients with a primary traumatic airway injury is one of the most difficult and most critical aspects of the care of these patients. The positioning of the patient is often one of the least “sexy” subjects of airway training yet it is one of the most critical. Patients that were improperly positioned was found to be the cause in 38% of failed intubation attempts[13]. Spinal immobilization can often be delayed until after the airway is secured. Keeping the patient in a left or right lateral recumbent position will make keeping the airway clear much easier. The patient should NOT be moved from a position that helps clear his or her airway until you are prepared to keep their airway clear. This means [at a minimum] have suction and oral/nasal airways ready to go. Extreme airway compromise may require you to prepare for RSI, before repositioning the patient. This is also where you may need to perform a Delayed Sequence Intubation (DSI), to facilitate suctioning and preoxygenation until your O2 saturation are above 93%. When it is time to position your patient for intubation, Back-up-Head-Elevated position, Ramping, or reverse Trendelenburg is the best option. Sitting the patient up between 20-30 degrees improves pre-oxygenation, increases safe apnea time, and reduces intubation-related complications[14][15]. This position increases FRC by taking the weight from the abdominal organs off the diaphragm allowing the diaphragm to expand and allows for airway fluids to drain down the esophagus while preventing contents from coming upwards. Rather than lifting up on the tongue or jaw, the intubater can merely push forward; this can explain why this position also increases first pass success rates[16]. Having suction ready is paramount to any airway as it obstructs and prevents proper oxygenation. In airways like these, there is no such thing as suctioning too aggressive. Practicing suctioning during training, preferably using the SALAD Simulator is best. The SALAD (suction-assisted laryngoscopy airway decontamination) pioneered by Jim DuCanto, MD, staff anesthesiologist and director of the simulation center at Aurora St. Luke’s Medical Center in Milwaukee. This simulator enables decontamination of the actively vomiting patient’s airway, control of continued emesis and intubation, all in a quick and easy manner. Click HERE to view a video on the SALAD Simulator.

 

 

 

Anytime the BVM is used, there should be a 2-hand technique applied to the mask. This technique improves tidal volume delivery, reduces mask leaks, and improves oxygenation[19]. The commonly taught C-E one-handed technique is inadequate for the average patient, let alone the critical patient. If you’re short on helping hands, you can have an assistant perform the 2-hand technique while you ventilate periodically while getting the airway equipment ready. This can help to prevent hyperventilation. I will also place the ETCO2 monitor between the BVM and mask. I primarily do this to ensure I am getting good ventilation delivery and volume return. If you are unable to get an ETCO2 reading on the patient, it could be that there is a mask leak or too much obstruction for the device to read. Although difficult, alternating suctioning and BVM ventilation for pre-oxygenation can be done with the patient in the lateral recumbent position. Oral airways can assist in keeping the patient’s tongue displaced and jaw in the open position to help facilitate airway clearance and ventilation

Definitive airway

 

 

I would recommend your most experienced intubator, since first pass success has shown to decreases mortality.  Using a Video laryngoscope on these airways has the best chance of first pass success, however, the blade must be inserted slowly, while you simultaneously suction. However, fixed channel laryngoscopes such as the Airtraq or King Vision may not be your best choice, as they rely on normal anatomy and a clear line of sight, two things you may not have when dealing with these airways. When using a VL that is shaped like a traditional DL, it is my recommendation to make your first attempt a direct look, only periodically glancing at the screen as a position reference. The DL to VL approach was first recommended by Rich Levitan in this SMACC video. This will prevent you from being lost in the event if the camera is covered by blood and keeps you from going past the vocal cords. As stated above, aggressive suctioning is a must and cannot be overstated or overused in this patient subset. Fluids and soiled airway contributes to 50% of failed airway attempts and aided in 43% of rescue airway attempts[21].

 

 

I personally use a bougie on all of my intubation attempts; you would be a lot safer if you did too. Many pre-hospital and flight services mandate the use of a bougie and recommended amongst many experts.  Any intubation attempt should be an attempt at epiglotoscopy, just identifying the epiglottis as you are certain the vocal cords lie behind it. You should slowly march the laryngoscope blade down the tongue until you see the uvula, if you are unable to see the uvula, then more suction is needed. Once you identify the uvula, slowly lift the blade as you slide it several centimeters forward, identifying the epiglottis then the vallecula. This method will keep you from making two mistakes, getting to close with your video laryngoscope creating the Kovacs sign, and going past the vocal cords all together and possibly witnessing glottic impersonation and placing the ET tube in the esophagus. Both of which are very easy to do in an airway with a significant amount of blood and trauma

 

In this subset of patients, limiting the amount of time between administration of the paralytic and placement of an airway is essential. All equipment should be out and ready to use, including your backup airways and surgical cricothyrotomy kit. In these scenarios, I verbalize to all the providers on the scene that we will make one attempt then proceed straight to surgical airway [if I can’t intubate, can’t ventilate] and place the surgical kit in plain sight. This acknowledges to myself as well as my team that we have a critical airway in which a surgical airway is a realistic outcome. By realizing this, I believe the decision making becomes more streamlined and straightforward, which is important in minimizing delays in oxygenation.

In recent years “Human factors” has been a subject on the forefront of emergency medicine, with leadership skills becoming a valuable skill set. Proper leadership and teamwork have shown to be directly contributed to patient outcomes and thus is just as important to work on as your clinical skills[26]. Decisions made in haste are rarely good decisions. The initial case above and the quick decision to immediately place the patient supine, without the tools to manage his airway contributed to his death. Recent studies have shown that in the critical trauma patient, response and scene times do not correlate to patient outcome[27]. This is why as emergency providers we must focus on performing invasive procedures correctly, rather than quickly. If there is an invasive procedure to be done, I fully recommend doing it stationary where you can establish leadership, develop an appropriate plan of action, have good communication, effective teamwork, utilize a checklist, and deliver the appropriate treatment.  Airway management performed during transport have increased the incidence of desaturations and complications[28]. The vortex approach is a good thing to have practiced with your fellow clinicians prior to meeting a difficult airway.

Take home data points

  • Positioning can be a deciding factor when dealing with patients with severe traumatic airways. It can assist with clearing fluids in the airway, assist with pre-oxygenation, and aid in your intubation attempt.
  • If positioning is the most important aspect, then suctioning is a close 2nd. Significant and continues suctioning is not uncommon in these patients.
  • Recognize anatomy during intubation, as it will be difficult to identify landmarks in a heavily soiled airway.
  • Never underestimate the power of good leadership and effective teamwork. Aids such as checklists and the vortex algorithm can facilitate this.
  • Hypoxia kills these patients. So be very aware of where the patient is on the oxyhemoglobin dissociation curve.

Case

You are a paramedic on an ALS ambulance. You’re requested by PD to the local bar where you find a  22yr old male lying face down in the parking lot. The police officer says the patient is intoxicated and was assaulted with a crowbar by another patron, who struck the patient in the face twice. You see copious amounts of blood coming from the patient’s mouth. The Patients GCS is 8 (E=3, S=2,M=3). You have your partner bring you the suction and you suction his airway. You place him on a backboard in a left lateral position and suction his airway while you move him to the ambulance. You instruct your partner to obtain vitals and instruct BLS to alternate between suctioning and giving O2 via blow by. You Ramp the stretcher prepare the intubation equipment. Vitals reveal HR=136 BP=152/108 RR=8 SPO2= 82% with blow by O2. You instruct BLS to keep alternating suctioning and oxygen while an IV is placed. You verbally state a detailed plan of action and that this is a potential surgical cricothyrotomy scenario while placing the kit on the bench seat; everyone on scene nods in agreement. The patients SPO2 reaches 93%, your partner administers the RSI medications, another round of aggressive suctioning is performed. After 30 seconds you roll the patient onto his back in the ramped position. The Paramedic slowly inserts his laryngoscope into the patient’s mouth, verbalizing what he sees. He then states he visualizes the epiglottis then the vocal cords; he inserts the bougie and advances until he feels hold-up. The ET tube is then inserted, confirmed by ETCO2 and auscultation. You monitored the patients SPO2 during the attempt and the lowest was 90%. The patients SPO2 quickly rises to 95%. After acknowledging a good job by everyone, you quickly transport to the nearest trauma center.

About the Author:

Wesley Rogers has been in prehospital EMS for over 8 years. He began as a volunteer fireman while in high school, and attended paramedic school at the age of 19. His experience includes ground critical care in a large urban-based EMS system and has spent the last 3 years as a Critical Care Flight Paramedic in Texas. Wesley’s  experience includes Field Training Officer, Critical Care Educator for U.S. Army Flight Paramedics, and providing AHA & NAEMT outreach education. Wesley is currently attending the University of Houston, majoring in Public Health.

References:

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