Healthcare workers caring for patients with viral severe acute respiratory infection — a considerable threat in the midst of the coronavirus disease 2019 (COVID-19) pandemic —have an increased risk of infection if they administer oxygen therapy to their patients, according to study results published in the Annals of Emergency Medicine.
For this study, a team of Canadian researchers conducted a systematic review of clinical trials published between 2000 and 2020 that described the risk of infection associated with different oxygen therapy modalities in patients with severe acute respiratory infection. Types of infections assessed were COVID-19, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome, and emerging or pandemic influenza. Oxygen therapy modalities included were intubation, noninvasive ventilation (bilevel positive airway pressure or continuous positive airway pressure), high-flow nasal cannula, bag-valve-mask ventilation, and face mask with or without reservoir and nasal cannula.
A meta-analysis of the studies was performed to assess the risk of a severe acute respiratory infection in healthcare workers administering these oxygen therapies to patients with infection. In total, 50 studies were included in the qualitative synthesis, whereas 16 studies that reported clinical outcomes were included in the meta-analysis. Only 3 of the studies included in the systematic review and meta-analysis assessed the risk of COVID-19 infection in healthcare workers. Another 18 studies assessed the risk of SARS transmission and 7 examined the risk of influenza virus.
In 12 observational studies with a pooled cohort of 2675 healthcare workers, the oxygen modalities most associated with an increased risk of infection included intubation (11 studies; odds ratio [OR], 6.48; 95% CI, 2.90-14.44), bag-valve-mask ventilation (3 studies; OR, 2.70; 95% CI, 1.31-5.36), and noninvasive ventilation (9 studies; OR, 3.96; 95% CI, 2.12-7.40). All oxygen therapy modalities produced air dispersion, which the investigators postulated “could easily facilitate transmission of the disease.”
Limitations of this meta-analysis were the inclusion of studies with small sample sizes as well as the limited number of COVID-19 studies available for analysis.
The investigators wrote that their findings could “contribute to the complex decision facing clinicians regarding the optimal modality of oxygen therapy for patients with severe acute respiratory infection by providing a better understanding of the risk involved, which can improve” the safety of healthcare workers while “reducing the global morbidity associated with severe acute respiratory infection.”
Cournoyer A, Grand’Maison S, Lonergan A-M, et al. Oxygen therapy and risk of infection for health care workers caring for patients with viral severe acute respiratory infection: a systematic review and meta-analysis. Ann Emerg Med. Published online August 10, 2020. doi:10.1016/j.annemergmed.2020.06.037