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Your unit is the first arriving ALS unit to the scene of a multi-story, single family structure fire. There were victims reported, and the first-due units have confirmed three during the primary search. Three victims have been removed from the fire and placed in the yard near your unit.
Victim 1 is an alert and conscious 28-year-old male who was found leaning out of a second story window. He was removed under his own power and assisted down a ladder to the treatment area. He is sitting up, breathing heavily in-between coughing fits. He appears winded after a coughing fit but appears to recover each time. His coughing is punctuated by the sound of him bringing up thick black mucous and spitting it on the pavement. He has no apparent burn injuries.
Victim 2 is an unconscious 26-year-old female who was found on the floor in a hallway. She was removed and brough to the treatment area; unconscious, unresponsive, with shallow respirations. You direct a teammate to place an NPA and begin BVM respirations on 100% oxygen as you move on to the third patient. She has no apparent burn injuries.
Victim 3 is an unconscious 22-year-old male who was found on the floor of a bathroom in the rear of the house. His shirt appears burned and there is evidence of singed hair, facial hair and eyebrows. He presents unconscious but roused with a sternal rub. As he catches his breath, he states that he was “working on something” in the bathroom when it blew up in his face, knocking him backwards. He apparently was knocked unconscious at some point during the explosion.
Burning Questions
Who needs aggressive emergency airway management right now?
Who can tolerate a delay?
Is intubation for protection the only reason to intubate any one of the victims?
For patients who have been involved in a fire, be it a flash fire from a barbecue grill or a house fire, difficulties come in three distinct flavors:1
1.) Direct thermal injury to the supraglottic structures.
2.) Chemical irritation of the respiratory tract.
3.) Systemic toxicity from cyanide and/or carbon monoxide inhalation.
Sometimes the patient may only have some localized irritation or swelling in the oropharynx, and in the most severe cases they suffer from all three types of inhalation injury.
The mechanism by which these different types of inhalation injuries occur (and therefore their severity) is influenced by several factors like the concentration of the smoke and heat. A person who breathes in some smoke from a burning dish on a stove top is not likely to suffer as dramatic consequences as that of a person who is found unconscious in a room where the walls and furniture were burning.
This is because the conscious individual naturally will protect their respiratory tract by holding their breath or attempting to breathe through something to filter the noxious smoke. An unconscious victim cannot do that and will breathe in the toxic fumes and super-heated air to a much greater degree and with more devasting consequences.
Direct thermal injury provides the more obvious indications for emergent airway management. Swelling is the most dangerous and ominous sign of impending airway doom. In the field, we do not know how much time the patient has before the swelling completely occludes the airway.
A delay in this case could be a detriment to the patient. The absence of soot or singing of nose hair is not reassuring that their airway has not suffered a burn of some degree, and edema formation and inflammation are not far behind. The threshold for taking over an airway that has signs of burn trauma should be very low.
While the swelling of an airway is certainly an anxiety producing event for a prehospital clinician, equally of concern is damage from inhalation of asphyxiants. Asphyxiants are the gasses and particles that inhibit oxygenation. Carbon Monoxide (CO) is the most well known asphyxiant.
It competes for and binds with hemoglobin (forming carboxyhemoglobin), displacing oxygen from the RBCs in the process.2 At room air, CO can remain in the system for 250 minutes, but once the patient is breathing 100% Fio2, the duration can drop to 40-60 minutes.2
Respiratory failure is also waiting for its turn to make the patient’s clinical course just a little bit more complicated. The super-heated gasses that make their way down into the lungs and the carbonaceous material that pollutes the airways from the nares to the alveoli can cause devastating damage anywhere along that path.
That damage causes inflammation and edema along the airways and manifests like ARDS. The lungs become less and less compliant, and as the patient continues to lose their ability to oxygenate the blood, MODS and organ failure ultimately lead to their demise. Earlier intubation does not necessarily prevent this from happening nor does it guarantee an attenuated clinical course for the patient.
Signs of Airway Burns/Irritation
The presence or absence of soot in and around the nares and the mouth does not reliably predict the presence or absence of injury further down the airway passages.3 It also, in isolation, should not be used as the primary reason to control the airway or not. Onishi et al studied 80 patients who had suffered an inhalation injury to identify what had the best predictive value for those patients who needed intubation.3
The highest predictive value was accessory muscle use, not singed nasal hair. 100% of the patients who exhibited accessory muscle use were intubated versus only 30% of those who presented with singed nasal hair were intubated. In fact, more patients (34%) were not intubated who had singed nasal hair than those that did. Other elements in the study that were associated with intubation were larger %BSA burns, burns to the anterior neck, and the COhb level.3
Some of the old standbys of airway management in burns should increase your index of suspicion for those who have been exposed to smoke or fire. Hoarseness of voice, throat pain, difficulty swallowing, or adventitious breath sounds should get your attention and push you to take a much closer look at the situation and assess for the need for early control of the airway.
Signs of Deterioration
One of my favorite adages comes from Dr. Jeff Jarvis: “ Patients do not suddenly become unstable, we suddenly notice.” This is quite true in the burn patient. Burns and the accompanying inflammatory processes are ongoing and progress for an indeterminate amount of time (variability is secondary to duration and severity of the burn). This means that the patient looks stable at the initial assessment but can become less so in a short amount of time.
Increasing accessory muscle use and altered mental status are the signals that you may be late in seeing the need to manage the airway. It cannot be overstated that in the burn patient, airway management must be attended to early in the patient’s clinical course lest we wait too long and we are in the midst of an airway disaster that could have been otherwise avoided.
Difficult Airway Management
Let’s assume that the operator makes the decision to intubate to either protect the airway or treat respiratory failure (or any one of the other reasons to control a burn patient’s airway).
The operator’s assessment of the airway and ventilatory status will be key in his or her success. Without completely rewriting one of the hundreds of articles on airway difficulty, we will focus on two particularly dangerous problems within the context of burns.
Swelling in the oropharynx is an obvious indicator of physical difficulty in securing the airway. It is one such difficulty that it puts the operator under a time pressure to secure the airway before the swelling completely obstructs the passage.
Contingency planning for these situations should move subglottic airway access (aka surgical airway) closer to the top of the plan instead of at the end, however, the prudent operator should note that any burns to the anterior neck can make it difficult to identify the landmarks externally.
Hypoxia in burn patients presents a physiologic difficulty that may not be overcome with the addition of high concentration oxygen alone. Remember, there is a possibility that asphyxiants (carbon monoxide and cyanide) have been inhaled into the lungs as well as super-heated gases that are actively damaging the lung tissues and creating an edematous mess that makes oxygenation difficult if not impossible.
As previously mentioned, CO is dangerous in that it inhibits the ability of oxygen to bind with hemoglobin and therefore be transported to the capillary beds in the tissues. Cyanide is another by-product of combustion that inhibits aerobic respiration at the cellular level.4
Closing Out
In the world of “resuscitate before you intubate,” burn patients are no exception. Intubation for airway protection and to facilitate further resuscitation to overcome difficulties with CO and cyanide toxicity is a necessary action.
The timing of that action can make the difference between a lower stress/lower acuity airway management situation and being presented with a rapidly deteriorating patient with rapidly deteriorating intubation conditions.
References
1. Dries DJ, Endorf FW. Inhalation injury: epidemiology, pathology, treatment strategies. Scand J Trauma Resusc Emerg Med. 2013 Apr 19;21:31. doi: 10.1186/1757-7241-21-31. PMID: 23597126; PMCID: PMC3653783.
2. Walker PF, Buehner MF, Wood LA, Boyer NL, Driscoll IR, Lundy JB, Cancio LC, Chung KK. Diagnosis and management of inhalation injury: an updated review. Crit Care. 2015 Oct 28;19:351. doi: 10.1186/s13054-015-1077-4. PMID: 26507130; PMCID: PMC4624587.
3. Onishi S, Osuka A, Kuroki Y, Ueyama M. Indications of early intubation for patients with inhalation injury. Acute Med Surg. 2017 Mar 6;4(3):278-285. doi: 10.1002/ams2.269. PMID: 29123875; PMCID: PMC5674455.
4. Sabri A, Dabbous H, Dowli A, Barazi R. The airway in inhalational injury: diagnosis and management. Ann Burns Fire Disasters. 2017 Mar 31;30(1):24-29. PMID: 28592930; PMCID: PMC5446904.
Cody Winniford is a flight paramedic and base manager in Baltimore, MD. He has a passion for sharing his professional experience in EMS and management. Cody’s clinical and leadership development background spans both military and civilian settings and has served in several capacities as a leader and prehospital clinician. He specializes in air medical and critical care transport, as well as organizational development and leadership development. He is an active speaker on various leadership and clinical topics and is an established and successful educator for prehospital clinicians of all levels. He has a passion for human performance improvement and the mental health and performance aspects of prehospital care.
