Study design and population
This was a single-center prospective observational study approved by the
Institutional Research Ethics Board. Signed informed consent was
obtained from all participants. The study population comprised
physicians, nurses, and medical trainees working at the Sheba Medical
Center ED between September and November 2020 who were assessed during
4-hour shifts while continuously wearing an N95 respirator. Subjects
with any health condition that could potentially put them at risk, such
as chronic obstructive pulmonary disease, uncontrolled asthma, pulmonary
hypertension, or poorly controlled heart failure, were excluded.
Baseline demographic data were collected, including age, gender, medical
history, and previous or active cigarette smoking.