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This starts with observing droplet precautions to prevent exposure to droplets larger than 5 microns in size, Charles Griffis, PhD, CRNA, said at a Society for Critical Care Medicine virtual meeting: COVID-19: What's Next. "These are particles exhaled from infected persons and which fall within around 6 feet and involve an exposure time of 15 or more minutes of contact," said Dr. Griffis, of the department of anesthesiology at the University of Southern California, Los Angeles. "We will always observe standard precautions, which include hand hygiene, gloves, hair and eye cover, medical mask, and face shield. We will observe these at all times for all patients and layer our transmission-based precautions on top."
During aerosol-producing procedures such as airway management maneuvers, tracheostomies, and bronchoscopies, very fine microscopic particles less than 5 microns in size are produced, which remain airborne for potentially many hours and travel long distances. "We will add an N95 mask or a powered air-purifying respirator (PAPR) device to filter out tiny particles in addition to our ever-present standard precautions," he said. "Contact precautions are indicated for direct contact with patient saliva, blood, urine, and stool. In addition to standard precautions, we're going to add an impermeable gown and we'll continue with gloves, eye protection, and shoe covers. The message is to all of us. We have to observe all of the infection precautions that all of us have learned and trained in to avoid exposure."
In terms of airway management for infected patients for elective procedures and surgery, recommendations based on current and previous coronavirus outbreaks suggest that all patients get polymerase chain reaction (PCR) tested within 24-48 hours of elective procedures or surgeries. If positive, they should be quarantined for 10-14 days and then, if asymptomatic, these patients may be retested or they can be regarded as negative. "Patients who are PCR positive with active infection and active symptoms receive only urgent or emergent care in most settings," said Dr. Griffis, a member of the American Association of Nurse Anesthetists Infection Control Advisory Panel. "The care provided to our patients, whether they're positive or not, is individualized per patient needs and institutional policy. Some folks have made the decision to treat all patients as infected and to use airborne precautions for all aerosol-producing procedures for all patients all the time."
When a COVID-19 patient requires emergent or urgent airway management because of respiratory failure or some other surgical or procedural intervention necessitating airway management, preprocedural planning is key, he continued. This means establishing the steps in airway management scenarios for infected patients and rehearsing those steps in each ICU setting with key personnel such as nurses, respiratory therapists, and medical staff. "You want to make sure that the PPE is readily available and determine and limit the number of personnel that are going to enter the patient's room or area for airway management," Dr. Griffis said. "Have all the airway equipment and drugs immediately available. Perhaps you could organize them in a cart which is decontaminated after every use."
He also recommends forming an intubation team for ICUs and perhaps even for ORs, where the most experienced clinicians perform airway management. "This helps to avoid unnecessary airway manipulation and minimizes personnel exposure and time to airway establishment," he said.
Always attempt to house the infected patient in an airborne isolation, negative-pressure room, with a minimum of 12 exchanges per hour and which will take 35 minutes for 99.99% removal of airborne contaminants after airway management. "These numbers are important to remember for room turnover safety," he said.
Patient factors to review during airway management include assessing the past medical history, inspecting the airway and considering the patient's current physiological status as time permits. Previously in the pandemic, intubation was used earlier in the disease course, but now data suggest that patients do better without intubation if possible (Am J Trop Med Hyg. 2020;102. doi: 10.4269/aitmh.20-0283). "This is because the pathophysiology of COVID-19 is such that the lung tissue is predisposed to iatrogenic barotrauma damage from positive-pressure ventilation," Dr. Griffis said. "In addition, COVID patients appear to tolerate significant hypoxemia without distress in many cases. Therefore, many clinicians now hold off on intubation until the hypoxemic patient begins exhibiting signs and symptoms of respiratory distress."
Options for delivering noninvasive airway support for COVID-19 patients include high-flow nasal cannula and noninvasive positive-pressure ventilation via CPAP or BiPAP. To mitigate the associated aerosol production, consider applying a surgical mask, helmet, or face mask over the airway device/patient's face. "Another measure that has proven helpful in general respiratory support is to actually put the patient in a prone position to help redistribute ventilation throughout the lungs," Dr. Griffis said (see Resp Care. 2015;60:1660-87).
To prepare for the actual intubation procedure, gather two expert intubators who are going to be entering the patient's room. The team should perform hand hygiene and don full PPE prior to entry. "It's recommended that you consider wearing double gloves for the intubation," he said. "Have the airway equipment easily accessible in a central location on a cart or in a kit, and use disposable, single-use equipment if possible. All of the usual intubation equipment to maintain a clear airway and give positive pressure ventilation should be arranged for easy access. A video laryngoscope should be used, if possible, for greater accuracy and reduced procedure time. Ready access to sedation and muscle relaxant drugs must be assured at all times."
For the intubation procedure itself, Dr. Griffis recommends ensuring that an oxygen source, positive-pressure ventilation, and suction and resuscitation drugs and equipment are available per institutional protocol. Assign one person outside the room to coordinate supplies and assistance. "Preoxygenate the patient as permitted by clinical status," he said. "A nonrebreathing oxygen mask can be used if sufficient spontaneous ventilation is present. Assess the airway, check and arrange equipment for easy access, and develop the safest airway management plan. Consider a rapid sequence induction and intubation as the first option." Avoid positive-pressure ventilation or awake fiber optic intubation unless absolutely necessary, thus avoiding aerosol production. "Only ventilate the patient after the endotracheal tube cuff is inflated, to avoid aerosol release," he said.
For intubation, administer airway procedural drugs and insert the laryngoscope – ideally a video laryngoscope if available. Intubate the trachea under direct vision, inflate the cuff, and remove outer gloves. Then attach the Ambu bag with a 99% filtration efficiency, heat-and-moisture exchange filter; and proceed to ventilate the patient, checking for chest rise, breath sounds, and CO2 production. "Discard contaminated equipment in designated bins and secure the tube," Dr. Griffis advised. "Attach the ventilator with an HMEF filter to protect the ventilator circuit and inner parts of the machine. Recheck your breath sounds, CO2 production, and oxygen saturation, and adjust your vent settings as indicated."
For post intubation, Dr. Griffis recommends securing contaminated discardable equipment in biohazard-labeled bins or bags, safely doffing your PPE, and retaining your N95 mask in the room. Remove your inner gloves, perform hand hygiene with soap and water if available, with alcohol-based hand rub if not, then don clean gloves. Exit the room, safely transporting any contaminated equipment that will be reused such as a cart or video laryngoscope to decontamination areas for processing. "Once clear of the room, order your chest x-ray to confirm your tube position per institutional protocol, understanding that radiology techs are all going to be following infection control procedures and wearing their PPE," he said.
For extubation, Dr. Griffis recommends excusing all nonessential personnel from the patient room and assigning an assistant outside the room for necessary help. An experienced airway management expert should evaluate the patient wearing full PPE and be double-gloved. "If the extubation criteria are met, suction the pharynx and extubate," he said. "Remove outer gloves and apply desired oxygen delivery equipment to the patient and assess respiratory status and vital signs for stability." Next, discard all contaminated equipment in designated bins, doff contaminated PPE, and retain your N95 mask. Doff inner gloves, perform hand hygiene, and don clean gloves. "Exit the room, hand off contaminated equipment that is reusable, doff your gloves outside, do hand hygiene, then proceed to change your scrubs and complete your own personal hygiene measures," he said.
Dr. Griffis reported having no financial disclosures.
"While the PPE used for intubation of a coronavirus patient is certainly more than the typical droplet precautions observed when intubating any other patient, the process and best practices aren't terribly different from usual standard of care: Ensuring all necessary equipment is readily available with backup plans should the airway be difficult," said Megan Conroy, MD, assistant professor of clinical medicine at The Ohio State University.
"We've been streamlining the team that's present in the room for intubations of COVID patients, but I'm always amazed at the team members that stand at the ready to lend additional assistance just from the other side of the door. So while fewer personnel may be exposed, I wouldn't consider the team needed for intubation to actually be much smaller, we're just functioning differently.
In my practice the decision of when to intubate, clinically, doesn't vary too much from any other form of severe ARDS. We may tolerate higher FiO2 requirements on heated high-flow nasal cannula if the patient exhibits acceptable work of breathing, but I wouldn't advise allowing a patient to remain hypoxemic with oxygen needs unmet by noninvasive methods out of fear of intubation or ventilator management. In my opinion, this simply delays a necessary therapy and only makes for a higher risk intubation. Certainly, the decision to intubate is never based on only one single data point, but takes an expert assessment of the whole clinical picture.
I'd assert that it's true in every disease that patients do better if it's possible to avoid intubation – but I would argue that the ability to avoid intubation is determined primarily by the disease course and clinical scenario, and not by whether the physician wishes to avoid intubation or not. If I can safely manage a patient off of a ventilator, I will always do so, COVID or otherwise. I think in this phase of the pandemic, patients 'do better without intubation' because those who didn't require intubation were inherently doing better!"
This article originally appeared in Chest Physician.
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Cite this: COVID-19 Airway Management: Expert Tips on Infection Control - Medscape - Sep 25, 2020.