Early on in the COVID-19 pandemic,
“We were concerned that, if we put them on high-flow nasal cannula or a noninvasive ventilation, that we would create aerosols that would then be a risk to clinicians,”
Respiratory support options
According to Dr. Lane-Fall, an associate professor of anesthesiology and critical care at the University of Pennsylvania, Philadelphia, there are two basic types of respiratory support in patients with moderate, severe, or critical COVID-19: noninvasive and invasive. Noninvasive options include CPAP or BiPAP which can be delivered through nasal pillows, masks, and helmets, as well as high-flow nasal oxygen. Invasive options include endotracheal intubation, tracheostomy, and extracorporeal membrane oxygenation (ECMO), usually the veno-venous (VV) form. “But it’s uncommon to need VV ECMO, even in patients who have critical COVID-19,” she said.
Factors that favor noninvasive ventilation include stably high oxygen requirements, normal mental status, ward location of care, and moderate to severe COVID-19. Factors that favor invasive ventilation include someone who’s deteriorating rapidly, “whose oxygen requirements aren’t stable or who is cardiopulmonary compromised,” said Dr. Lane-Fall, who is also co–medical director of the Trauma Surgery Intensive Care Unit at Penn Presbyterian Medical Center, also in Philadelphia. Other factors include the need for other invasive procedures such as surgery or if they have severe to critical COVID-19, “not just pneumonia, but [illness that’s] progressing into [acute respiratory distress syndrome],” she said.
Indications for urgent endotracheal intubation as opposed to giving a trial of noninvasive ventilation or high-flow nasal oxygen include altered mental status, inability to protect airway, copious amounts of secretions, a Glasgow Coma Scale score of less than 8, severe respiratory acidosis, hypopnea or apnea, shock, or an inability to tolerate noninvasive support. “This is a relative contraindication,” Dr. Lane-Fall said. “I’ve certainly talked people through the BiPAP mask or the helmet. If you tell a patient, ‘I don’t want to have to put in a breathing tube; I want to maintain you on this,’ often they’ll be able to work through it.”
Aerosolizing procedures require attention to location, personnel, and equipment, including personal protective equipment (PPE), said Dr. Lane-Fall, who is an anesthesiologist by training. “When you are intubating someone, whether they have COVID-19 or not, you are sort of in the belly of the beast,” she said. “You are very exposed to secretions that occur at the time of endotracheal intubation. That’s why it’s important for us to have PPE and barriers to protect ourselves from potential exposure to aerosols during the care of patients with COVID-19.”
In February 2020, the non-for-profit Anesthesia Patient Safety Foundation published. A separate guidance was published the based on emergency tracheal intubation in 202 patients with COVID-19 in Wuhan, China. “The idea here is that you want to intubate under controlled conditions,” said Dr. Lane-Fall, who is an author of the guidance. “You want to use the most experienced operator. You want to have full PPE, including an N95 mask, or something more protective like a powered air purifying respirator or an N95 mask with a face shield. You want the eyes, nose, and mouth of the operator covered completely.”
CPR, another aerosolizing procedure, requires vigilant safety precautions as well. “We struggled with this a little bit at our institution, because our inclination as intensivists when someone is pulseless is to run into the room and start chest compressions and to start resuscitation,” Dr. Lane-Fall said. “But the act of chest compression itself can create aerosols that can present risk to clinicians. We had to tell our clinicians that they have to put on PPE before they do CPR. The buzz phrase here is that there is no emergency in a pandemic. The idea here is that the good of that one patient is outweighed by the good of all the other patients that you could care for if you didn’t have COVID-19 as a clinician. So we have had to encourage our staff to put on PPE first before attending to patients first, even if it delays patient care. Once you have donned PPE, when you’re administering CPR, the number of staff should be minimized. You should have a compressor, and someone to relieve the compressor, and a code leader, someone tending to the airway. But in general, anyone who’s not actively involved should not be in the room.”