COVID-19 pandemic and non invasive respiratory management: Every Goliath needs a David. An evidence based evaluation of problems

Abstract

Background and aim: The war against Covid-19 is far from won. This narrative review attempts to describe some problems with the management of Covid-19 induced acute respiratory failure (ARF) by pulmonologists.

Methods: We searched the following databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and reviewed the references of retrieved articles for additional studies. The search was limited to the terms: Covid-19 AND: acute respiratory distress syndrome (ARDS), SARS, MERS, non invasive ventilation (NIV), high flow nasal cannula (HFNC), pronation (PP), health care workers (HCW).

Results: Protection of Health care workers should be paramount, so full Personal Protective Equipment and Negative pressure rooms are warranted. HFNC alone or with PP could be offered for mild cases (PaO2/FiO2 between 200-300); NIV alone or with PP may work in moderate cases (PaO2/FiO2 between 100-200). Rotation and coupled (HFNC/NIV) strategy can be beneficial. A window of opportunity of 1-2h is advised. If PaO2/FIO2 significantly increases, Respiratory Rate decreases with a relatively low Exhaled Tidal Volume, the non-invasive strategy could be working and intubation delayed.

Conclusion: Although there is a role for non-invasive respiratory therapies in the context of COVID-19 ARF, more research is still needed to define the balance of benefits and risks to patients and HCW. Indirectly, non invasive respiratory therapies may be of particular benefit in reducing the risks to healthcare workers by obviating the need for intubation, a potentially highly infectious procedure.

Keywords: Acute respiratory failure; Chest physiotherapy; Health care workers; High flow nasal cannula; Non invasive ventilation; Pronation.

Figure 1

Powered Air Purifying Respirator (CleanSpace Halo®, CleanSpace Technology Pty Ltd, Artarmon, NSW Australia, NIOSH (US) and ATEX (Europe) approved).