Strayerisms - Why Do We Intubate?

Strayerisms: Why Do We Intubate?

Reuben Strayer MD

Take Home Points

• Although we often say we are intubating for airway protection, we are usually intubating for another reason. It is important to use the correct terminology and indication.
• There are six reasons to intubate; airway, breathing, circulation, disability, expected course and agitated delirium.
• Signs of impending airway obstruction include stridor, voice change, mishandling secretions and posturing.
• A significant proportion of people have an absent gag reflex at their baseline and the presence of a gag reflex does not demonstrate adequate airway reflexes

• Intubation for airway protection. Why do we always say we are intubating for airway protection? Most of the time we don’t mean that we are intubating for airway protection. Airway protection is a mysterious concept. Try asking five emergency providers how you can tell if a patient is or isn’t protecting their airway.
• There are six reasons to intubate.
• Airway. However, this is not about protection but about obstruction. You need to get ready for a tough intubation because there is a good chance that the obstruction that indicates intubation will make intubation difficult or impossible. For example, mouth or neck infections like epiglottitis or Ludwig’s angina, ENT tumors, foreign bodies and bleeding into the airway. Bleeding is especially bad because the blood that is choking your patient will also choke your videolaryngoscope and line of sight. Be ready.
• Dynamic airway obstructions deserve special mention as these have the possibility to rapidly evolve so that an easy intubation may be impossible in five minutes. Neck trauma, anaphylaxis, angioedema, thermal airway injuries, bullets, bites and burns. When a patient with one of these problems demonstrates one of the airway signs (stridor, voice change, mishandling of secretions and posturing), move quickly.
• Breathing. This is probably the most common reason why we intubate in the emergency department. These patients have diseases that cause failure of oxygenation or ventilation including asthma, COPD, pneumonia, pulmonary edema, pulmonary fibrosis, etc. Most of these patients will have normal airways. They should be easier to intubate than the previous group. However, they may have a high oxygenation deficit and drop their saturation as soon as your push drugs. You need to take specific measures to address this prior to intubation. If you use a paralytic, you may need to go fast. Fortunately the majority of patients who used to be intubated for a breathing problem may be temporized or stabilized with non-invasive ventilation.
• Circulation. Intubation is often an insult to the circulation of sick patients due to the sympatholysis of the induction agent and the preload reduction of positive pressure ventilation. There are some patients who require intubation to unload the muscles of ventilation because they are at the end of their metabolic rope. This is most commonly occurs in severe sepsis. Resuscitate these patients before you intubate. Use strategies to minimize the impact of sympatholysis such as reducing the dose of the induction agent or using a non-paralyzing breathing intubation technique with small tidal volumes.
• Disability. Patients with neurologic catastrophes such as intracranial hemorrhage or status epilepticus and patients with CNS depression for overdose. These are the patients who need to be intubated for airway protection as they can’t protect their airway and are at risk for aspiration. These patients generally have normal airways, heart and lungs. The focus should be on brain protection by reducing the impact of the procedure on hemodynamics and intracranial pressure. A less common subset of patients who need to be intubated is those with neuromuscular weakness such as myasthenia gravis, Guillain-Barre, etc. The gag reflex is not an acceptable indicator of airway protection.
• A significant proportion of people have an absent gag reflex at their baseline and the presence of a gag reflex does not demonstrate adequate airway reflexes. It is hard to justify performing a maneuver known to precipitate vomiting in patients where you are concerned about their ability to protect their airway. Evaluate the ability to handle secretions. Obtunded patients who are vomiting do need to be intubated for airway protection.
• Expected course. These are the patients where you are concerned they will develop an A, B, C or D reason to intubate at a time when it will be less safe to do so, such as in the CT scanner or during transfer to another institution. These patients are often the most challenging as you are trying to predict the future. The preferred error considers how much harm you will do if you are wrong and how likely you are to be wrong. If you intubate a patient who didn’t need intubation, what harm have you done? Some small harm. There is a risk you might not get the airway (unlikely) or other complications. However, what is the risk of not intubating a patient who later requires a crash intubation which is more dangerous? If you look at it this way, most of the time when you aren’t sure whether or not to intubate, intubate.
• Feral. These are the patients who need to be intubated because they are so agitated that the best way to manage their threat is induction and intubation. This indication is less relevant now that we are comfortable using dissociative dose ketamine as a tranquilizer. We intubate seriously injured trauma patients whose agitation prevents their care but we fail to consider this strategy in other very sick patients who are agitated. Delayed sequence intubation may be the right approach if the patient is unable to cooperate with proper preparation. Dissociate with ketamine, prepare and paralyze (or not).
• Let’s clean up our terminology about intubation. Most of the patients we intubate are not intubated for airway protection. Know your indications for intubation and the management priorities unique to each indication.