Bronchoalveolar lavage as a method for removing aerosol particles with predominantly fibrogenic action

Introduction. Currently recommended methods of treatment of pneumoconiosis in the Russian Federation are mainly symptomatic. While approaches aimed at eliminating the cause of the disease, such as removing dust particles from the lungs, are practically not used in domestic clinical practice. It is believed that dust particles from the lungs can be removed using bronchoalveolar lavage (BAL), including total. However, despite the widespread use of the latter abroad in the treatment of pneumoconiosis, the effectiveness of removing dust particles from the lungs with its help remains questionable. This is due to the fact that the data available in the literature on the mass of quartz dust extracted from the lungs of patients with silicosis by the BAL method do not take into account its initial content in the respiratory tract. Since it is necessary to standardize lung dusting in workers in order to conduct such an assessment, it is not possible to do this in the framework of clinical trials. In this regard, it seems reasonable to conduct experimental studies to study the effectiveness of BAL as a method of removing aerosol particles of predominantly fibrogenic action from the lungs.The study aims to quantify the effectiveness of removing aerosol particles of predominantly fibrogenic action from the lungs by bronchoalveolar lavage.Materials and methods. The authors performed studies on white male Wistar rats weighing 250-300 g. Pneumoconiosis was modeled using intratracheal (i/t) injection of a suspension (fractions 1–5 microns) of quartz dust at a dose of 50 mg in 1 ml of 0.9% NaCl solution. After that, the experts have randomized the animals by body weight into three groups (six individuals each). In Group 1, a single BAL with large (10ml) volumes of lavage solution was performed immediately after the quartz dust administration, after which the animals were euthanized. In Group 2, a single BAL with large volumes of 0.9% NaCl solution was performed on the 28th day after quartz dust instillation, after which the animals were sacrificed. In turn, in Group 3, three BAL with small (3.3 ml) volumes was performed on the 7th, 14th, and 28th days, after which the animals were euthanized. The lavage fluid (LF) isolated from the animal was collected by scientists in a test tube to determine the total amount of quartz dust. Regardless of the BAL method used, the total volume of lavage fluid was fixed at ~10 ml. The scientists determined the amount of quartz dust in the lavage fluid and lungs using the gravimetric method. They analyzed the composition of the lavage fluid using light microscopy.Results. When studying the quartz dust content, it was found that in Group 1 it was the highest in comparison with other groups, both in the lungs and in the LF. At the same time, the sum of the quartz dust masses in the lungs and LF was equal to the mass of dust initially injected into the animal (50 mg). After the BAL, 84% of quartz dust remained in the lungs.In turn, Group 2 had lower amounts of quartz dust in the lungs and LF compared to Group 1.It was also noteworthy that the sum of the masses of quartz dust in the lungs and lavage fluid was significantly (p