The following is a summary of “Risk of air and surface contamination during application of different noninvasive respiratory support for patients with COVID-19,” published in the August 2023 issue of the Infectious Disease by Hui et al.

Researchers compared the risk of environmental contamination among COVID-19 patients treated for respiratory failure with a nasal high-flow nasal cannula (HFNC), noninvasive ventilation (NIV), and conventional oxygen therapy (COT). There were 12 air changes per hour in the hospital isolation chambers, where 26 patients with COVID-19 received HFNC (up to 60 l/min, n = 6), NIV (n = 6), or COT (up to 5 l/min of oxygen). 

During air sampling, surface samples were collected from 16 patients. Air samples from patients receiving HFNC (3/54, 5.6%), NIV (1/54, 1.9%), and COT (4/117, 3.4%) contained comparable levels of viral RNA (P = 0.579). Similarly, the risk of surface contamination was equivalent for patients receiving HFNC (3/46, 6.5%), NIV (14/72, 19.4%), and COT (8/59, 13.3%) (P = 0.143). 

By univariate logistic regression, an increase in the cyclic thresholds of the upper respiratory specimen before air sampling was associated with a decreased risk of SARS-CoV-2 detection in the air (odds ratio 0.83 [95% confidence interval 0.69-0.96], P = 0.027). The use of HFNC and NIV versus COT in patients with COVID-19 and respiratory failure was not associated with an increased risk of environmental contamination in isolation rooms. Positive air samples had a higher viral burden in the respiratory specimens.

Source: sciencedirect.com/science/article/pii/S120197122300560X