Avoid Intubation When Possible
I view every non-intubation as an exponential win, not only for the patient but for the system from a resource perspective. Figuring out who flies and who doesn’t with a non-intubation strategy requires trying to asses where they are on the timeline of illness and to gauge carefully the work of breathing, respiratory rate, heart rate, and inflammatory markers, not just oxygen saturation improvement.
Explore This IssueACEP Now: Vol 39 – No 05 – May 2020
In my experience, and from the experience of my co-authors on the awake proning paper, most patients who will do well with proning show significant improvement in respiratory rate, heart rate, and subjective dyspnea quickly. If a patient is following commands and willing to work with you, I think they deserve a chance to avoid intubation. These patients need to be watched very closely, however. Disconnection from oxygen quickly causes desaturation. A high-flow nasal cannula adds much higher flows and augments the work of breathing much more than a standard nasal cannula combined with a face mask; augmentation of the work of breathing requires 40 L/min. and usually higher flows. I think these are much better tolerated than continuous positive airway pressure (CPAP) systems, especially in patients who are awake proning. Clinicians should use proning as part of an escalating oxygenation strategy, as detailed by many FOAMED sources. Hospitals effectively using a non-ventilation initial strategy round on these patients regularly—every one to two hours—checking respiratory parameters and closely communicating with patients. Patients who feel they are tiring or do not have documented improvements in respiratory rate, heart rate, etc. may need intubation. Proning seems to be very beneficial in many patients, but in our article, intubation was still required in about a third of patients.
If you do have to intubate a patient, be really careful with your personal protective equipment (PPE). I recommend “CRF4G,”an acronym for cap, respirator, full face shield, base layer of gloves and gown, and a top layer of gloves and gown. It is best do intubations in a negative pressure room and minimize the number of people who go in the room. When you come out of the patient’s room, shed the top layer, wash your base layer gloves, and then go somewhere and get out of the PPE, breathe, and cool down.
I think the best way to intubate COVID-19 patients is to sit them upright and use CPAP before intubation. I put a viral filter and a positive end-expiratory pressure (PEEP) valve on every bag-valve mask. Then push K-roc—which sounds like a radio station but stands for ketamine and rocuronium—at 1.5 mg/kg to 2.0 mg/kg of each drug. Some clinicians recommend succinylcholine instead of rocuronium for faster onset, but at these higher doses, I think the onset times are comparable. Then hold the CPAP mask against the patient’s face for 45 seconds. They will go apneic, but you have CPAP on them. Maintain the PEEP. At 45 seconds, lay them down just as far as necessary to come from above and do your video laryngoscopy. The moment you break that mask seal to intubate them, their pulse oximetry will fall. As many clinicians have noted, COVID pneumonia patients do not seem to get the bradystolic instability common in most rapid sequence intubation (RSI) patients as oxygen falls. I believe this is because they have “acclimatized” in a way to the hypoxia over days before coming in. They do require a ton of sedation, however.
Remember that these patients’ brains are fine—they aren’t encephalopathic from acute hypoxia, hypercarbic (not narcotized), or in shock with poor brain perfusion—so giving them a large dose of ketamine is important. I’ve found ketamine much better than etomidate. You also have to start multiple sedatives to keep them effectively sedated and their heart rate and blood pressure down. Most patients I encountered required three agents: propofol, fentanyl, and either midazolam or dexmedetomidine. Gauging adequate sedation is really important; there seems to be a high incidence of post-traumatic stress disorder related to patients’ being intubated, and needing mechanical ventilation for a prolonged period of time (five to 10 days is not at all uncommon).
Be very careful of your depth of tube placement. I gave up on using stethoscopes for this, but it’s likely that chest X-rays are going to be seriously delayed if the emergency department and hospital are really busy. When you hit the full pandemic spike, everything stops working or slows to a point that it becomes dysfunctional. You have to anticipate that the system is not going to be able to help you should things go south. Double- and triple-check where you secure the tube.
Post-intubation, have your ventilator ready with an inline CO2 detector so you can put it right on and you don’t have to bag.