Hey Folks, Here is a case report that Chris Hicks posted. It is great, with the added pay-off of the Hicksian COVID airway checklists. Vide infra –Weingart
Vatsal Trivedi, MD(1)
Michael Baxter, MD(2)
Christopher Hicks, MD(3,4)
Alberto Goffi, MD(1,4)
1. Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada
2. Department of Anesthesiology and Pain Management, University of Toronto, Toronto, Ontario, Canada
3. Division of Emergency Medicine, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
4. St. Michael’s Hospital, Unity Health Toronto, Toronto, Ontario, Canada
Approximately 5% of patients with Coronavirus Disease 2019 (COVID-19) require intensive care and mechanical ventilation (1). As we prepare for an increased burden of illness from COVID-19 (2), we can expect that a significant proportion of patients with risk factors for difficult intubation will require endotracheal intubation. Indeed, recent evidence suggests that the incidence of difficult intubation in all-comers, defined as Cormack-Lehane Grade 3-4, is approximately 10% (3). This poses unique challenges, including the safety of patients and healthcare workers. We report our experience with management of an anticipated difficult airway in a patient under precautions for suspected COVID-19 in the Intensive Care Unit (ICU). Verbal consent was obtained from a patient representative.
The patient was admitted to the ICU for hypoxemic respiratory failure and sepsis. Numerous physiological and anatomical risk factors for challenging intubation and ventilation were identified. Patient factors included morbid obesity (weight >160kg, Body Mass Index >50), severe obstructive sleep apnea and obesity hypoventilation syndrome, male sex, age greater than 65 years, pulmonary hypertension (right ventricular systolic pressure 55 mmHg), and hemodynamic instability. Anatomic factors included poor dentition, Mallampati score 3, borderline thyromental distance (2-3 finger breadths), large neck circumference, reduced neck range of motion, and poorly palpable anterior neck anatomy. No prior documentation of airway management was available. The patient was placed in a negative pressure room under airborne, contact and droplet isolation precautions, and this was continued while planning for urgent intubation.
The management of this anticipated difficult airway required multidisciplinary care and preparation. Roles were identified, including the most experienced operator managing the airway, a physician skilled with resuscitation managing induction and resuscitative medications, a respiratory therapist (RT) to assist with airway management, and the primary bedside nurse to assist with medications and communication. A second RT, wearing personal protection equipment (PPE), was available in the anteroom should any immediate assistance be required. Observers outside the patient room were instructed to document medications given and vital signs, and to observe and notify contamination events or process issues.
Plans for contingencies were made, particularly the availability of cardiac arrest drugs, difficult airway equipment, and help as needed outside the patient room. Equipment was confirmed and prepared while still outside the patient room. This included the appropriate PPE for airborne, contact and droplet precautions (level 4 gown, two pairs of gloves – extended cuff and regular length cuffs, N95 mask, eye protective goggles, full-face shield, and surgical bouffant), mechanical High Efficiency Particulate Air (HEPA) filters for the ventilatory circuit, in-line suction catheters, multiple sized tubes, capnography monitor, oropharyngeal airway, supraglottic airway device, fiberoptic bronchoscope, and scalpel with bougie. These recommendations are highlighted in recent publications (4, 5). Personnel donned their PPE prior to entering the patient room and proper donning was ensured through a peer-monitoring process. The sequence of events was detailed in a pre-procedural huddle outside of the patient room.
In the patient room, noise was minimized, and appropriate infusion lines, power cords, and monitors were organized to minimize movement of healthcare personnel. Difficult airway algorithms were modified: “Plan A” and “Plan B” for airway management were in the patient room, while “Plan C” was available in the anteroom, and “Plan D” onwards were available immediately outside the patient room. Plan A included videolaryngoscopy with a stylet placed a priori. Plan B included direct laryngoscopy with the use of gum elastic bougie. The patient was preoxygenated for 5 minutes with tight-fitting face mask with PEEP valve, with addition of a mechanical HEPA filter immediately distal to the mask. Medications for rapid sequence induction favoured opioid (fentanyl 3mcg/kg) and paralysis (rocuronium 1.2mg/kg) with low-dose anesthetic (ketamine 0.5mg/kg) to prevent coughing. No bag-mask ventilation was performed. With videolaryngoscopy (Glidescope, Verathon Inc., Bothell, WA) and a stylet, intubation was successful and the cuff was inflated.
The patient was only ventilated following closure of circuit with a mechanical HEPA filter and sidestream capnography in place. Auscultation was not performed given direct visualization of intubation with videolaryngoscopy and sustained end-tidal carbon dioxide on capnography. Following intubation, proper doffing steps were guided by the RT (acting as “safety officer”) in the anteroom for each healthcare worker, and debriefing was immediately undertaken with observers outside the room.
High quality evidence on ideal intubation timing is currently lacking. When indicated, intubation should be performed in a controlled environment (ICU, operative room, emergency department) in an airborne infection isolation room with negative pressure. The intubation should be carried by the most experienced provider available, with minimization of the number of staff exposed to aerosols, and time spent in the isolation room. This applies to any aerosol generating procedure, including cardiopulmonary resuscitation, intubation, extubation, bronchoscopy, open suctioning, tracheostomy, bag-mask ventilation, non-invasive mechanical ventilation (NIMV), high flow nasal cannula oxygenation, and nebulization of medications. NIMV may be more likely to cause aerosol spread, delayed intubation, and high rate of treatment failure in patients with COVID-19, and is therefore not recommended unless indicated for an alternative reason (COPD exacerbation, acute pulmonary edema) and applied in an airborne isolation room (6).
Preparation for airway management should involve donning and doffing of appropriate PPE for airborne isolation precautions. Checklists for the procedure:
and for equipment required
are suggested to reduce cognitive burden. Before entering the room, an interprofessional pre-brief is essential to create a shared mental model for the team, and to establish a common understanding of roles and priorities (Pre-brief Protected Intubation v3). This can also be used to consider room spacing, equipment layout, and logistics prior to entering the room. Medications for induction, post-procedure sedative/analgesic infusions, and vasopressors should be prepared outside the patient room to minimize time spent in the room. Medication choices should support minimization of coughing, rapid paralysis and appropriate depth of anesthesia.
Video-laryngoscopy is favoured to increase distance between airway operator and patient; however, the technique that maximizes first-pass success and minimizes patient risk should ultimately be chosen by the person performing the intubation with consideration of patient factors. Awake intubation is discouraged as large volume aerosolization is likely to occur with topicalization of the airway and coughing through the procedure. Following successful intubation and closure of circuit, ventilation may proceed, with capnography/capnometry as the primary method of confirmation. In the event of challenging intubation/laryngoscopy, auscultation with a disposable stethoscope can be considered to confirm endotracheal placement, in addition to capnography. Doffing should occur slowly and carefully to avoid inadvertent contamination. A “safety officer” should be observing and guiding the correct doffing procedure. Post-procedure debrief with the team is suggested to improve the safety of the process/equipment, as well as psychological safety of the team members involved.
This case highlighted several logistical challenges that we have learned from. Many contamination points exist in patient rooms, including power cords, organ support machines, and intravenous poles. These compound the safety concerns for healthcare workers in the room, and economy of space must be optimized, with changes identified during the pre-brief. Communication in the room may be challenging with PPE and clear, loud voices must be used. Mobile resuscitative towers with standardized equipment bundles for arterial and venous access are suggested. These assist in minimizing PPE use, multiple donning/doffing sequences that expose risk to providers, and maximize efficiency and safe delivery of care while inside the patient room.
Managing the protected difficult airway requires a multidisciplinary approach, expert operators and teams, and protocolized preparation, execution, and debriefing. In light of this, the most difficult aspect of this airway management may not be the act of endotracheal intubation, but rather reducing cognitive burden for the operators, and maintaining appropriate safety and protection of both patients and healthcare workers.
We would like to thank Dr. Laurent Brochard for his guidance and review of the manuscript.
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2. Murthy S, Gomersall CD, Fowler RA (2020) Care for Critically Ill Patients With COVID-19. JAMA. https://doi.org/10.1001/jama.2020.3633
3. Detsky ME, Jivraj N, Adhikari NK, et al (2019) Will This Patient Be Difficult to Intubate?: The Rational Clinical Examination Systematic Review. JAMA 321:493–503. https://doi.org/10.1001/jama.2018.21413
4. Canada PHA of (2020) Infection prevention and control for coronavirus disease (COVID-19): Interim guidance for acute healthcare settings. In: aem. https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus-infection/health-professionals/interim-guidance-acute-healthcare-settings.html. Accessed 17 Mar 2020
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6. Alhazzani W, Møller MH, Arabi YM, et al Surviving Sepsis Campaign: Guidelines on the Management of Critically Ill Adults with Coronavirus Disease 2019 (COVID-19). 101