The goal of this interventional is to assess advantages of the ultrasound examination of the lungs in the early postoperative period in cardiac surgical patients after heart surgeries requiring cardiopulmonary bypass. Evaluation of pulmonary complications and outcomes during mid-term follow-up, as well as comparison of ultrasound examination and traditional roentgenologic methods (X-ray examination and CT of the chest) will be performed. The main question\[s\] it aims to answer are: * Is ultrasound examination of the lungs a more specific and sensitive method in identification of early postoperative pulmonary complications after on-pump cardiac surgical procedures, in comparison with traditional X-ray methods. * Does early identification of interstitial pulmonary edema (based on number of visualised B-lines in the early postoperative period), influences mid-term outcomes in this cohort of patients Participants will undergo ultrasound examination of the lungs on postoperative day 1, 3, 5 and 7 after heart surgery. Based on ultrasound findings and degree of interstitial pulmonary edema, medical (diuretics, anti-inflammatory, e.t.c) therapy will be modified. Researchers will compare this group of patients with control group, in which ultrasound examination will be performed in the same time frames, but no changes in medical management based on ultrasound findings will be made to see if timely administered medical therapy, based on ultrasound findings, can significantly improve symptoms, hospital lengths of stay and outcomes of this patients.