Interhospital transfer of COVID-19 patients treated with high-flow nasal oxygen therapy

At the start of the COVID-19 pandemic, early intubation was recommended on the basis of worldwide observations of severe hypoxemia. However, some patients were ultimately able to benefit from high-flow nasal cannula (HFNC) and thus avoid intubation. During the "second wave" (September to December 2020 in France), some emergency departments implemented HFNC in patients with severe COVID-19. The question then arose regarding the transfer of these most serious patients to intensive care units (ICU) and of the respiratory modalities to be used during this transfer. To assess the feasibility of interhospital transfers of COVID-19 patients needing HFNC, we conducted a bi-centric prospective observational study of all medical transfers of patients needing HFNC with the Chambery and Angers (France) mobile emergency and intensive care service (SMUR) during the "second wave" of the COVID-19 pandemic in France. Analysis of these 42 patients showed no significant variation in the respiratory requirements during the transfer. Overall, 52% of patients were intubated during their stay in ICU, including three patients intubated before or during transfer. Interhospital transfer with HFNC is very high-risk, and intubation remains indicated in the most unstable patients. However, 48% of patients benefited from HFNC and were thus able to avoid intubation during their transfer and ICU stay; for these patients, intubation would probably have been indicated in the absence of available HFNC techniques.