Oct. 11, 2016
One day last summer, emergency medical services (EMS) responded to a 911 call from the scene of a car crash 25 miles north of Rochester, Minnesota. The 56-year-old male driver had blunt head injuries, a Glasgow Coma Score less than 5, facial trauma, blood in the airway, and arm and leg fractures. When EMS weren't able to successfully intubate him in the field, they inserted a King Airway — a single-lumen tube that obstructs the esophagus and provides direct ventilation through the larynx and trachea.
"The King Airway can be easier to place than an endotracheal tube," explains Stephanie F. Heller, M.D., a trauma surgeon at Mayo Clinic's campus in Minnesota. "It's a blind insertion — you don't have to be able to see. You put it in the patient's mouth, and in adults, it preferentially goes into the esophagus, even if there is a great deal of blood in the airway. Yet it's not a very good device; it doesn't actually protect the airway or prevent aspiration, and it sometimes becomes plugged."
In this case, poor saturations raised concern about the King Airway, and the team discussed other airway options, including intubation via a laryngoscope versus an immediate surgical airway in the emergency department (ED).
"At Mayo, we use a laryngoscope with a video camera so when we look into the airway, everyone is working from the same visualization," Dr. Heller says. "But this can be much more challenging in trauma patients, who usually have blood in the airway and broken teeth and broken facial bones — everything that goes along with head trauma that leads to a failed intubation in the first place."
She explains that although intubation was a consideration for this patient, it is common at Mayo Clinic to perform a tracheostomy or cricothyroidotomy instead, not only because intubation is challenging in patients with severe head injuries but also because they are likely to need a tracheostomy during their hospital stay. In these patients, early tracheostomy improves outcomes.
"We have tried intubating head injury patients after King Airway placement enough times to know that the success rate is low, and the attempt itself puts patients at risk. Any desaturation can worsen outcomes," Dr. Heller says. "Most of these patients have blood on or in the brain and may be unconscious or in a coma for weeks, which means they will eventually need a tracheostomy. So we feel quite strongly about doing it early and advocate for it."
That decision may be made at the start of the primary survey.
"We are always worried about a King Airway, so we immediately assess how it is doing," Dr. Heller says. "If it seems to be doing well, we leave it in acutely, finish the primary survey and perform the secondary survey, looking for other injuries; the patient may even go to CT for a head-to-pelvis scan because if there is a ruptured spleen, we want to deal with that before the surgical airway.
"But if during the primary survey the patient isn't able to move air well or maintain good saturation, we will stop right there and perform a tracheostomy or cricothyroidotomy. If the airway is in trouble, we don't even think about circulation or a ruptured spleen. The airway is the most important thing, and we need a definitive airway quickly.
"In nontrauma patients, it's common for the King Airway to be changed out via laryngoscope or bronchoscope because there aren't the same issues with facial and head injuries."
An alternate case
What about patients who are conscious and have severe facial injuries but not head trauma?
"If they are breathing on their own, protecting their airway and are conscious, EMS will often allow them to breathe on their own, even if their face looks horrible," Dr. Heller says. "But once in the ED, decisions need to be made about how best to help these patients."
For instance, once a patient is sedated for intubation, the airway collapses with bleeding and swelling. In that setting, the best option is an awake intubation or tracheostomy.
Dr. Heller explains: "Allow the patient to be wide awake, numb the airway, then try to intubate over a bronchoscope, which can weave through the nooks and crannies of swollen tissue while the patient is holding everything open for you. Or, if the injury is so severe you can't slide a tube through, an awake tracheostomy is also an option."
In smaller hospitals, airway management decisions may be different but equally challenging. They are often based on how long it seems likely a patient can protect the airway during transport to a higher level of care.
"If a patient doesn't have enough reserves to protect the airway for the entire trip, you try to intubate or place a King Airway or do a tracheostomy, depending on the skill of the provider. And if you feel there is an impending problem and the airway may be acutely at risk, it may be time to activate the helicopter," Dr. Heller says.