CPAP, high-flow nasal O2 to treat COVID not linked to heightened infection risk

In a new study, the use of CPAP and high-flow nasal oxygen to treat patients with moderate to severe COVID-19 did not produce higher levels of air or surface viral contamination in the immediate environment compared with supplemental oxygen.

“Our findings show that the noninvasive breathing support methods do not pose a higher risk of transmitting infection, which has significant implications for the management of the patients,” Danny McAuley, MD, professor at Queen’s University Belfast, Northern Ireland, and consultant in intensive care medicine at the Royal Victoria Hospital, Montreal, said in a related press release. “If there isn’t a higher risk of infection transmission, current practice may be over cautious measures for certain settings, for example preventing relatives visiting the sickest patients, whilst underestimating the risk in other settings, such as coughing patients with early infection on general wards.”

The observational, environmental-sampling study included 30 patients hospitalized with COVID-19 (mean age, 56 years; 13 women) at three centers in the U.K. from December 2020 to February 2021. All patients had a fraction of inspired oxygen of 0.4 or more to maintain oxygen saturation of 94% or more. Patients received supplemental oxygen (n = 10), CPAP (n = 10) or high-flow nasal oxygen (n = 10). Researchers collected a nasopharyngeal swab, three air samples and three surface samples from each participant and the clinical environment.

Twenty-one patients (70%) tested positive for SARS-CoV-2 RNA by PCR nasopharyngeal swab at the time of assessment. Four (4%) air samples and six (7%) surface samples tested positive for viral RNA. An additional 10 samples were suspected to be positive in both air and surface samples.

The use of CPAP or high-flow nasal oxygen or coughing in this patient population was not associated with significantly more environmental viral contamination compared with the use of supplemental oxygen, according to the researchers.

Of 51 positive or suspected-positive samples, only one sample from the nasopharynx of a patient who received high-flow nasal oxygen was culture-positive, according to the results.

“This adds to the increasing evidence that for COVID-19, CPAP and high-flow nasal oxygen may not be procedures with a higher transmission risk that are associated with their ‘aerosol-generating’ classification. Rather, health care worker exposure and nosocomial transmission may be more influenced by patient factors, such as coughing at earlier stages of infection, than the type of respiratory support used,” the researchers wrote in Thorax. Healio