The Difficult Airway
Creator:
Dr. David Snow
Published:
8/4/2016
Intro
What is a more appropriate start to an EM blog than an airway discussion? Let’s start with the basics and expand as we progress through the year.
Most of this discussion comes from the teaching I received from Airway Guru Dr. Steve Carleton (Cincinnati Dept of EM) and Dr. Ron Wall’s Manual of Emergency Airway Management (a book that every resident should buy and read).
The Case
A 23 year-old female presents by EMS. A friend called EMS, and the patient is unable to provide any history given her decreased mental status. There is a strong smell of ethanol on her breath.
On exam, her respirations are coarse and somewhat sonorous. She has no obvious exam findings of trauma. She does respond to painful stimuli.
Vitals: 130/80, 37.1, 12, 92% RA, 120 bpm
On exam, her respirations are coarse and somewhat sonorous. She has no obvious exam findings of trauma. She does respond to painful stimuli.
What do I do?
Deciding to RSI & intubate is a difficult one. This patient is in front of you, and your attending is (nervously) looking at you – asking if you should intubate her. You are unsure, and rightly so, and several questions start percolating:
Does she require intubation at this time?
Will I cause more harm by doing so? Remember that RSI + Failed Intubation = Death (and a death that you played a part in)
Are there basic principles to review to help with this decision?
Rules of the Road
Consider the following as the key reasons to intervene on your patient's airway:
Failure to oxygenate
Failure to ventilate
Inability to protect airway
Anticipated clinical course
Failure to Oxygenate
Failure to maintain adequate oxygenation, despite supplemental oxygen, in a condition that is not reversible is a cause for intubation. Possible reversible causes include pulmonary edema or other conditions where the use of noninvasive positive pressure ventilation (NIPPV) can help overcome the pathophysiology at hand. Opioid overdose or something similar is another reversible cause.
Failure to Ventilate
Same as the above. Worsening hypercapnia that does not respond to other measures will eventually require intubation. Altered mental status from a post-ictal state and severe COPD exacerbations are two common causes for ventilatory failure and subsequent hypercapnia requiring intubation.
Airway Protection
Answer this question by standing next to the patient, observing their ability to control their secretions. Pooling of secretions in the oral cavity is a sign that the patient may have lost the ability to safely swallow, with these secretions likely leaking into the trachea and making its way to the lungs – greatly increasing morbidity and mortality.
Clinical Course
This rule pertains to the patient that at this moment in time does not break any of the above 3 rules. However, such is the nature of their presenting problem, you know they will progress to the point where this will happen, and intubation early is a smart move. Good examples of this are angioedema patients who are not responding to standard treatments, yet in front of you are protecting their airway and are adequately oxygenating and ventilating – but you know that if the observed swelling or respiratory distress is allowed to continue this will be a much harder patient to intubate.
Back to Our Patient
Now let’s think back to your patient, and apply the rules 1 by 1:
Oxygenation: Her oxygen sat is 97% on 2L by NC
Ventilation: You place a nasopharyngeal airway, and raise the head of her bed, and her sonorous breathing improves. You feel that at this time she is ventilating adequately, but make the decision to place End-Tidal CO2 to help with this thought going forward
Airway Protection: She is controlling her secretions, swallowing adequately, with no pooled secretions in her oropharynx
Clinical Course: This remains uncertain at this point. You are unsure if she has ingested anything else with the large amount of ethanol that is likely on board.
You make the decision to not intubate on initial presentation. You feel that you can continue your workup and provide frequent reassessments, keeping the golden rules at the front of your thoughts as you progress.
You relay your plan to your (somewhat nervous) attending. They subsequently appear less nervous knowing you have a plan and it was thoughtfully crafter.
Well played young Doctor, well played.
Future Thoughts
The above patient doesn’t improve with time. You know you have to intervene. You are unsure whether to give meds or not, and at that moment your attending gets pulled into a room to deliver a pre-term infant…should you or should you not RSI your patient? And if so, how?