Objectives: We compared the risk of environmental contamination among COVID-19 patients who received high flow nasal cannula (HFNC), non-invasive ventilation (NIV), and conventional oxygen therapy (COT) via nasal cannula for respiratory failure. Method: Air was sampled from the hospital isolation rooms with 12 air changes/hr where 26 COVID-19 patients received HFNC (up to 60L/min, n=6), NIV (n=6), or COT (up to 5L/min of oxygen, n=14). Surface samples were collected from 16 patients during air sampling. Results: Viral RNA was detected at comparable frequency in air samples collected from patients receiving HFNC (3/54, 5.6%), NIV (1/54, 1.9%), and COT (4/117, 3.4%) (p=0.579). Similarly, the risk of surface contamination was comparable among patients receiving HFNC (3/46, 6.5%), NIV (14/72, 19.4%), and COT (8/59, 13.6%) (p=0.143). An increment in the cyclic thresholds of the upper respiratory specimen prior to air sampling were associated with a reduced SARS-CoV-2 detection risk in air [OR 0.83 (95%CI 0.69 – 0.96), p=0.027] by univariate logistic regression. Conclusion: No increased risk of environmental contamination in the isolation rooms was observed in the use of HFNC and NIV versus COT among COVID-19 patients with respiratory failure. Higher viral load in the respiratory samples was associated with positive air samples.

Fuente: International Journal of Infectious Diseases
Available online 12 May 2023