**5. NIV in COVID-19 pneumonia**

Covid 19 pandemic caused devastation across the world with hospitalization in 5–15% and 5% requiring ICU due to severe and critical hypoxic failure. Secondary to severe covid pneumonia and ARDS. NIV has been used from the beginning of pandemic with China reporting NIV works well and results were similar to that of HFNC in Covid 19. They also reported no nosocomial outbreaks of Covid 19 infection in health cares in ICU units which used NIV. Europe started using CPAP with variable *Non-Invasive Ventilation in Acute Hypoxemic Respiratory Failure DOI: http://dx.doi.org/10.5772/intechopen.104720*

success rates as well as concerns. Initial reports of NIV use in Covid 19 showed that CPAP trial succeed in 40% when used in those requiring >15 L/min of O2 by nonrebreathing mask with baseline SpO2/FiO2(SFR) of >110, RR > 30/min and NLR > 8. Repeat SFR at 30–120 min improved in all patients but cut off of SFR 180 was the best predictor of success or failure of CPAP trial but patients who failed had high mortality (38%) [10]. Intubation rates and mortality in Covid 19 patients who received NIV was similar to the group which received HFNC. European Respiratory Society Living Guideline for management of Covid 19 has recommended use of NIV with helmet or full face mask to treat acute hypoxic respiratory failure secondary to coronavirus infection provided there is no immediate indication for IMV [11]. But caution must be exercised in close monitoring to identify signs of NIV failure in Covid pneumonia. There have been reports of full recovery in COVID-19 patients even after extensive lung involvement by judicious noninvasive ventilation strategies linked with prone ventilation [12–14].
