The purpose of this study is to investigate the potential for inhaled NO to reduce clinical worsening of hospitalized, high-risk patients with early COVID-19 to progressive systemic de-oxygenation, intubation, and death. This is a pilot randomized-controlled (2:1) open label investigation of inhaled NO to prevent progression to more advanced disease in hospitalized patients with COVID-19 at risk for worsening, based on baseline systemic oxygenation and 2 or more of the major risk factors of age 60 years, type II DM, hypertension, and obesity.