BACKGROUND: Synchronous independent lung ventilation (ILV) is the treatment of choice for unilateral pathology of lung parenchyma. Numerous studies have documented the improved blood oxygenation and clinical efficacy of this procedure. The aim of the present study was to evaluate the effects of ILV on the selected biomechanical parameters of the lungs.METHOD: The study involved ASA I-II patients undergoing thoracic surgery in the lateral decubitus position under the standard conditions of general anaesthesia with the thoracic cavity closed. ILV with equal separation of the tidal volume was performed with a prototype volume separator, using incremental a PEEP of 0-15 cm H₂O in the dependent lung. Peak pressures, dynamic compliance and airway resistance of both lungs were evaluated.RESULTS: The study included 36 patients. In all of the patients, a PEEP of 5-15 cm H₂O in one lung increased its peak pressures, dynamic compliance and resistances, and variably affected the biomechanical parameters of the other lung. Irrespective of patient positioning on the right or left side, the highest compliance was recorded at a PEEP of 10 cm H₂O.CONCLUSIONS: In ILV, peak pressures and airway resistances are higher in the dependent lung compared to compliances in the non-dependent lung. ILV with a PEEP of 5-15 cm H₂O increases the biomechanical parameters of the dependent lung while variably influencing the parameters in the non-dependent lung.
Adult Airway Resistance