Adjunctive measures before definitive intervention of COVID-19 patients (Table 2)
Non-invasive ventilation such as HFNC has been utilized widely in COVID-19. Initial high flow oxygen should be given immediately for patients with obvious respiratory distress or weak cough ability. In the University of Chicago, HFNC combined with prone positioning have shown remarkable results in the treatment of COVID-19 patients in respiratory distress. In patients who are clinically stable, a lower oxygen flow can be started, gradually increasing the oxygen flow if necessary. The use of HFNC could pre-emptively prevent patient deterioration, hence avoiding intubation and mechanical ventilation. A surgical mask should also be worn by the patient to reduce the risk of virus transmission through droplets or aerosols. However, it should still be noted that elderly patients are vulnerable for failed HFNC, requiring other intervention such as intubation in order to maintain respiratory requirements.
Although CPAP/BiPAP machines units with an exhalation filter could theoretically support SARS/COVID-19 patients with respiratory failure, there is a high incidence of CPAP/BiPAP mask leak which may result in inadvertent leak of aerosolized virus. If used out of appropriate airborne/droplet isolation, there are increased transmission risks. CPAP/BiPAP machines may also lead to delayed deterioration in patients, resulting in a greater incidence of emergent intubations. Hence, CPAP/BiPAP machines should be avoided in patients with COVID-19 and should only be considered in appropriate airborne/droplet isolation settings on a case by case basis.