SARS-CoV2-associated adult respiratory distress syndrome (COVID19-ARDS) frequently leads to fatal respiratory failure in COVID19. Currently, there is no curative treatment option for severe COVID19-ARDS other than mechanical ventilation therapy and extracorporal membrane oxygenation (ECMO). We investigated whether modification of the kallikrein-kinin system in vivo attenuates the progression of SARS-CoV2-induced ARDS. The aim of the study was to investigate the effect of blockade of the B2R on the course of COVID19-ARDS. In an observational study including 53 COVID19-ARDS patients, patients received the bradykinin-2-receptor antagonist (B2RAg) icatibant. After icatibant substitution, respiratory rate in COVID19-ARDS reduced by a maximum of 32% (24.9/min to 16.8/min) with a concomitant reduction in oxygen substitution by 59% (6.1 LO₂/min to 2.5 LO₂/min). The data show that the use of icatibant in the early phase of COVID19-ARDS is suitable to stabilize pulmonary gas exchange. Furthermore, early icatibant substitution seems to be able to reduce the rate of necessary invasive ventilation in COVID19-ARDS. Observational data suggest that inhibition of bradykinin signalling leads to stabilization of lung function in SARS-CoV2-associated ARDS. Further prospective placebo-controlled studies are needed to investigate the impact of the kallikrein-kinin system on the development of COVID19-ARDS in vivo.

The clinical data of the patients was stored anonymously in an internal database. The analysis for the present study was performed from the database.
For the data collected during the treatment of patients with the B2R antagonist, icatibant, it is important to note that the drug treatment was in the form of an "off label use".