April 16, 2020

COVID-19 Webinar: IH Shares Best Practices for Protecting Healthcare Workers

A webinar held April 15 by the National Institute of Environmental Health Sciences featured practical information for minimizing healthcare workers’ exposure to SARS-CoV-2, the virus responsible for the COVID-19 pandemic. Jim Chang, CIH, of the University of Maryland Medical Center (UMMC) in Baltimore, discussed ways to isolate COVID-19 patients and minimize contacts between patients and healthcare workers.

Chang’s presentation focused on negative-pressure isolation rooms, which are designed to prevent airborne microorganisms in patients’ rooms from entering hallways and corridors. Many of the isolation rooms at UMMC are pressurized at negative 0.01 inch water gauge, provide more than 12 air changes per hour, and are directly exhausted to the outside, Chang said.

He clarified that updated guidelines from CDC no longer require negative pressure rooms for patients infected with SARS-CoV-2. The agency recommends reserving those rooms for infected patients who are undergoing aerosol-generating procedures, Chang said. However, since SARS-CoV-2 patients are constantly generating aerosols when they cough, sneeze, and talk, UMMC continues to place them in negative-pressure isolation rooms.

“As long as we can make negative-pressure rooms, that’s going to be our standard of care,” Chang said, though he acknowledged that UMMC won’t be able to do so indefinitely.

Chang recommended that occupational health and safety professionals speak with building engineers to get their perspective on the best way to implement negative-pressure rooms. Hospital-grade machines with high-efficiency particulate air filters can be used to remove contaminants from the rooms. Chang warned that these machines are noisy and that some patients unplug them so they can sleep.

While many hospitals have existing negative-pressure airborne infection isolation rooms, or AIIRs, these are often spread throughout a facility, which presents difficulties for healthcare workers who are trying to cohort COVID-19 patients. “Your burn rate [for PPE] goes through the roof,” Chang said, because workers are donning and doffing respirators and other protective gear as they move in and out of contact with infected patients.

UMMC created wards where entire clusters of patient rooms were under negative pressure. While this approach allows for the most efficient use of PPE, it also requires healthcare workers to remain in the “hot zone” for long periods of time as they provide care to infected patients, Chang said.

Staff at UMMC improvised ways to conserve PPE by minimizing interaction with infected patients. For example, staff used extension tubing to locate intravenous pumps in hallways, allowing them to attend to the devices without entering patient rooms. The ventilators at UMMC have detachable control interfaces, so staff located these, too, outside patient rooms. Monitoring of patient rooms is done remotely, through the use of tablet computers.