Researchers from McMaster University reviewed evidence about the benefits and harms of alternative noninvasive and invasive ventilation strategies in acute hypoxic respiratory failure in patients infected with COVID-19. Indirect evidence related to other coronaviruses and evidence related to virus transmission to healthcare workers was also examined. Based on the evidence, they conclude that use of noninvasive ventilation, similar to invasive mechanical ventilation, probably reduces mortality but may increase the risk for transmission of COVID-19 to healthcare workers.
Schünemann, et al. (2020) sought to review multiple streams of evidence regarding the benefits and harms of ventilation techniques for coronavirus infections, including that causing COVID-19. The researchers included in their review 123 studies (45 on COVID-19, 70 on SARS, 8 on MERS), but only 5 studies (1 on COVID-19, 3 on SARS, 1 on MERS) adjusted for important confounders. A study in hospitalized patients with COVID-19 reported slightly higher mortality with noninvasive ventilation (NIV) than with invasive mechanical ventilation (IMV), but 2 opposing studies, 1 in patients with MERS and 1 in patients with SARS, suggest a reduction in mortality with NIV (very low-certainty evidence). Two studies in patients with SARS report a reduction in mortality with NIV compared with no mechanical ventilation (low-certainty evidence). Two systematic reviews suggest a large reduction in mortality with NIV compared with conventional oxygen therapy. Other included studies suggest increased odds of transmission from AGPs.
The researchers concluded that indirect and low-certainty evidence suggests that use of NIV, similar to IMV, probably reduces mortality but may increase the risk for transmission of COVID-19 to healthcare workers.
Read the full text: https://www.acpjournals.org/doi/10.7326/M20-2306.
Reference: Schünemann HJ, Khabsa J, et al. Ventilation Techniques and Risk for Transmission of Coronavirus Disease, Including COVID-19. Ann Intern Med. May 22, 2020.