Synthetic Analogue of Leu-Enkephalin in COVID-19 (a Prospective Clinical Study)

Abstract

One of the main problems facing intensivists when treating patients with COVID-19 is severe and critical acute respiratory distress syndrome (ARDS) with the underlying viral pneumonia. The current guidelines of the Russian Ministry of Health (Version 15 of 22.02.22) do not include drugs with a lung protective effect. This issue could be solved by administration of a synthetic analogue of leu-enkephalin.Aim. Study the efficacy of a synthetic analogue of leu-enkephalin in ARDS in patients with COVID-19.Materials and methods. The study included 35 patients divided into 2 groups. Group 1 (main) patients (n=15) in addition to standard therapy received a continuous infusion of synthetic analogue of leu-enkephalin at a rate of 5 µg/kg/hour for 5 days. Patients from group 2 (control, n=20) were treated according to the Temporary Guidelines of the Ministry of Health (V.15), but without the synthetic analogue of leu-enkephalin. The radiological data, frequency, severity and evolution of respiratory complications, changes in P/F (PaO2/FiO2) ratio, as well as changes in the scores of prognostic APACHE II, SOFA, and NEWS scales were evaluated.Results. In patients taking the studied drug, the percentage of lung damage did not change with the median (IQR) of 0 [–8; 0], while in the control group it increased by approximately 10% with the median (IQR) of +10,0 [+2; +20] (P=0.001). The proportion of patients in group 1 with positive disease evolution within 5–9 days after treatment initiation was significantly higher and reached 46.7 [24.8; 69.9]%, whereas in group 2 it was 15.0 [5.2; 36.0]% (P=0.04). Also, in group 1, starting from day 4, the median P/F ratio was significantly higher than in group 2 reaching 220 [185;245] versus 127 [111;158], respectively (P=0.014). The need for non-invasive lung ventilation in group 1 on day 7 averaged 7%, while in group 2 it was as high as 45.0%, which was significantly higher than in the main group (P=0.013).Conclusions. The use of synthetic analogue of leu-enkephalin according to the specified regimen had a significant impact on the main parameters of the viral pneumonia severity. The results serve as a rationale for the development of a novel effective treatment strategy to supplement the current standard COVID-19 management.