Background Angiotensin-converting enzyme 2 (ACE2) is not only the entry route of SARS-CoV-2 infection but also triggers a major mechanism of COVID-19 aggravation by promoting a hyperinflammatory state, leading to lung injury, hematological and immunological dysregulation. The impact of ACE2 inhibitors on the course of COVID-19 is still unclear. The effect of ACE2 inhibitors on the course of acute respiratory distress syndrome (ARDS) during COVID-19 and other severe respiratory infections in conditions of hyperferritinemia (HF) was investigated. Methods A cohort study of critically ill patients with COVID-19 and other respiratory diseases (widespread infection, pneumonia) who underwent treatment in The Critical Care Unit of the First University Clinic (Tbilisi, Georgia) during the 2020–2021 years was conducted. The impact of the ACE2 inhibitors on the course of the ARDS developed during COVID-19 and other severe respiratory infections in conditions of different severity of HF was evaluated. Results In COVID-19-infected (I) and uninfected (II) patients with ARDS, ACE2 inhibitors reduce the levels of Ang II, C reactive protein (CRP) and D-dimer (I: from 1508.07 ± 26.68 to 48.51 ± 24.35, from 233.92 ± 13.02 to 198.12 ± 11.88, from 7.88 ± 0.47 to 6.28 ± 0.43; II: from 1000.14 ± 149.49 to 46.23 ± 88.21, 226.48 ± 13.81 to 183.52 ± 17.32, from 6.39 ± 0.58 to 5.48 ± 0.69) at moderate HF and Ang II, CRP levels (I: from 1845.89 ± 89.37 to 49.64 ± 51.05, from 209.28 ± 14.41 to 175.37 ± 9.84; II: from 1753.29 ± 65.95 to 49.76 ± 55.74, 287.10 ± 20.50 to 214.71 ± 17.32) at severe HF, reduce interleukin-6 (IL-6) expression at moderate HF (I: from 1977.23 ± 354.66 to 899.36 ± 323.76) and cause reduction of pCO 2 index at severe HF (I: from 69.80 ± 3.22 to 60.44 ± 2.20) in COVID-19-infected patients. Conclusion Study results show that the ACE2 inhibitors play an important role in the regulation of inflammatory processes in both COVID-19-infected and uninfected patients with ARDS. ACE2 inhibitors decrease immunological disorders, inflammation, and lung alveoli dysfunction, especially in COVID-19-infected patients.