The article deals with the first comparative study of haemodynamics, gas exchange, and metabolic lung function in patients with underlying respiratory and cardiovascular diseases. Different anaesthesia and ventilation (conventional AVL, ОLV, differentiated ALV) techniques were used. Respiratory support methodology with the use of HFV or CPAP during the main phase of thoracic surgery in patients with severe associated cardio-respiratory diseases was developed. Indications for differentiated ALV in thoracic surgery were developed.