Ventilator-Induced Lung Injuries (an Experimental Study)
Objective: to evaluate the impact of high-frequency jet ventilation (HFJV) and traditional positive end-expiratory pressure (PEEP) ventilation on blood oxygenation, gas exchange, and hemodynamics on an experimental model of acute lung injury. Material and methods. Thirty albino outbred laboratory male rats weighing 200-300 g were randomly selected for investigations and further divided into groups: 1) traditional ventilation (TV) (n=15); 2) HFJV (n=15). The rats were anesthetized with intraabdominal ketamine (6-8 mg/kg) and sibasone (15-45 mg). Anesthesia was maintained by the bolus administration of ketamine (1 mg/kg every 15-20 min). Tracheostomy was carried out with a 0.2-0.4 mm diameter endotracheal tube that was then fixed using surgical thread 2-2.5 cm deep to the cricoid cartilage. Results. Acute respiratory distress syndrome (ARDS) has clear histological criteria for lung tissue structural injury; it is widely prevalent in clinical practice and associated with high mortality rates. The paper describes an experimental ARDS model, the essence of which is 45-55% aspiration of the circulating blood volume for 10-15 minutes. A Reosorbilact® solution was used to compensate for the volume of blood loss, which was followed by the administration of autothromboplastin (16-20 mg/kg animal weight). PEEP was studied for its impact on gas exchange, hemodynamics, and blood oxygenation during HFJV and TV. Gas exchange parameters during TV and HFJV were comparatively analyzed. Conclusion. The use of PEEP for ARDS was ascertained to improve blood oxygenation due to decreased pulmonary shunt, better respiratory muscle performance, lower infiltrated and atelectatic tissue volumes, and higher lung functional residual capacity.