The Fallacy of “GCS <8 Intubate” and the Decision to Intubate

“GCS is less than 8 means you intubate.” This is a gross over-simplification of the most difficult aspect of airway management: The decision to take over and manage a patient’s airway. Not to mention it incorrectly orients clinicians only to consider airway management in those that meet that GCS threshold, despite it being well established that there are patients who present with a GCS > 8 that often require airway management.

To the novice airway practitioner, this “GCS rule” may seem to be a great mental shortcut to avoid all of the agonizing over whether or not to intubate a patient. But there might be a better way. Dr. Kovacs outlines such a decision-making schema in the Airway Management in Emergencies textbook. In this article, we will unpack this schema and dive into some clinical situations to help us build a better mental model to support the decision to take a patient’s airway. Most treatment protocols include the following criteria as triggers for the initiation of airway management:

1.) Is the patient able to maintain their own airway?
2.) Is the patient able to ventilate effectively?
3.) Is the patient able to oxygenate effectively?
4.) Is the patient expected to deteriorate so that failing to manage the airway will create future complications acutely?

On the surface, these are not bad triggers for airway management, but they do not engage clinicians to evaluate the situation in its entirety. The astute clinician can recognize that there are obviously more than 4 notable triggers and that these decisions are made along a spectrum of “forced to act” to “elective.” The decision is now more informed by assessing both the situational urgency and the degree of difficulty present. Proper contingencies can be implemented to avoid poor outcomes and address difficulties as they arise.

There are four general categories of patients who require airway management, ranging from those who literally have no patent pathway for oxygen to travel from the atmosphere to the bloodstream; all the way to those where we may need to take their airway away from them electively to facilitate their transport to definitive care. Along with these clinical indicators, a situational urgency must be considered, which is along a spectrum of “right now” to “maybe later; it depends.”

Obtain/Maintain

In evaluating the Obtain/Maintain situation, a prehospital team would be confronted with a patient who has some airway obstruction:

Functional – Mental status deterioration to the point they cannot consciously maintain their own airway.

Mechanical – Foreign body airway obstructions, tongue, or teeth. Anything that is physically
blocking the glottic opening that is not allowing airflow. One could argue that suctioning and
clearing an airway can correct this issue without using adjuncts and tubes, which is true. In this context, we are discussing further protecting the airway from recontamination or repeat blockages from foreign bodies.

Pathological – Tumors, edema, swelling from multiple airway attempts, epiglottitis. This airway
is actively closing, and a clinician must take action to protect the passage. In some instances, the swelling and loss of access to the glottic opening may be less severe than in others. Nonetheless, delaying airway management can only make these situations all the direr. This is a “manage now” situation in which there will be harm and great detriment to the patient if
we cannot/do not secure and maintain the patient’s airway.

Resuscitate

In some cases, a team may be presented with a patient that has intact airway protective reflexes and is functionally maintaining their own airway but is still failing to ventilate and/or oxygenate effectively enough to keep up with their metabolic needs. In this case, airway management may be necessary to facilitate the resuscitation of an underlying problem. It is not an airway problem per se, but controlling the patient’s airway, oxygenation, and ventilation is necessary to restore acid-base balance and ensure adequate oxygen delivery.

In this context, the timing of airway management is more of a “the earlier, the better” timeframe than a “do it now” timeframe. If resuscitation is adequate and aggressive enough that cardiac output is restored so that a patient can consciously protect their own airway, then perhaps aggressive airway management can be delayed… for a time. However, should it be delayed too long, the patient’s disease process may now be a large complicating factor, and the margin of safety may be quite narrow. In this context, the risk of waiting to intubate may dramatically increase the likelihood of a patient’s poor outcome or adverse event.

I like to use a fire department analogy here. When a person calls the fire department for a fire in their home, they do not wait until the entire house is on fire to call someone to put it out. They call immediately as they know that the sooner the firefighters can put the fire out, the better off their homes and lives will be. Likewise, with airway management, the sooner the airway is controlled, the sooner the patient is oxygenated/ventilated, and the better off they are.

Elective vs. Forced to Act

What we have been talking about thus far are situations where a clinician is forced to act and take deliberate actions to secure a patient’s airway. They are relatively straightforward, black-and-white decisions. In this context, a patient will likely not survive their clinical course if the clinician cannot/does not secure the airway and begin ventilation and oxygenation of the patient. On the other hand, elective control of the airway is where clinicians may have a choice to take control of a patient’s airway or not. There are both arguments and indicators to take over an airway, as well as indicators and arguments for trying a different approach, if not abandoning the approach altogether.

Perception of Protection

In cases of anticipated loss of protective reflexes, a clinician may elect to intubate a patient to protect the airway preemptively. This is when the prehospital clinician asks, “Can the patient maintain their own airway?” The decision is traditionally based on the patient’s Glasgow Coma Scale (GCS). However, using the GCS is not without some controversy.

The GCS was originally developed to assess mental status and airway protection ability in trauma patients and has since been extrapolated to include every patient encountered in the prehospital environment.1 At its inception, it was strongly supported because of the logical conclusion that the patient’s protective reflexes become less effective in tandem with a reduction in their level of consciousness. Logically, this makes sense; however, there is some science that warrants mention, particularly the complete lack of evidence that a patient loses their gag reflex when their GCS drops below 8. In one study, 37% of patients with a GCS between 9 and 14 had lost their gag reflex, 63% had no gag reflex with a GCS < 8, and surprisingly 22% of patients with a GCS of 15 had no gag reflex.

Stated it is not evidence-based practice to intubate a patient based solely on their GCS. The question then becomes, what do we use to trigger the decision to intubate a patient? When evaluating a patient’s ability to protect their own airway, clinicians should evaluate the following:

1.) Is the patient aware of obstructions/secretions/fluids in their oropharynx?
2.) Is the patient trying to clear those obstructions/secretions/fluids (coughing, sitting forward, etc.)?
3.) Can the patient continue that effort for the long term, perhaps with minimal assistance (e.g., suction only)?
4.) Is the patient able to follow commands?
5.) Is the patient answering questions, or at least attempting to?
An assessment like this does not require 10 years of experience to conclude that a patient is managing their own airway with intact protective reflexes. It is quite binary, a patient is either aware of and actively working to clear secretions/obstructions from their airway, or they are not.

Expected Clinical Course

In this situation, a clinician is essentially looking into their transport-specific crystal ball and predicting how well their patient will maintain their airway throughout the transport. These are “Later/It Depends” airway management situations. The scenarios that we can use to present this are infinite, and what it really comes down to is how well the transport team answers the following questions:

• What is the real potential for mental status/clinical deterioration during the transport? What clinical indicators are you using to inform your gestalt?
• Does the patient need to be intubated to facilitate the transport? Meaning the patient poses some safety risks in which the crew and patient can only guarantee their safety by taking over the patient’s airway.
• If things go bad in transport, is this an airway situation we want to manage in an aircraft/ambulance? Is it a known difficult airway in which it is a better idea to intubate before transport where there are plenty of resources and room to work?
• If the patient’s condition worsens from what it is now, the airway management situation will not only be incredibly complicated think physiologic difficulty). Still, it may not even be physically feasible (think actively changing airway anatomy), forcing a more invasive approach where one may not have been indicated earlier.

Each question has an infinite number of clinical scenarios/presentations that a transport team may experience. Clinical experience plays a role in how these problems will be addressed. This is where it is incredibly important to put a few extra minds in the decision-making process to assist the transport team that may be struggling with what is “right” vs. “wrong.”

Conclusion

In a very broad sense, the physical action of intubating a patient or placing a supraglottic airway
is the easiest part of managing an airway. Sure, there are difficulties to be encountered during the procedure. But for the most part, astute clinicians have many tools at their disposal to minimize and mitigate those difficulties. By far, the most difficult part of managing an airway is the multifactorial decision to take over and manage a patient’s airway. I hope this has provided you with a mental model for that decision.

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