Lung Ultrasound for the Detection of Pulmonary Atelectasis in the Perioperative Period

Atelectases (collapsed lung areas) of 15-20% of total lung occur in up to 90% of patients who are anaesthetized and intubated. The goal of the present prospective study is to detect atelectatic areas in the perioperative period in the lungs of patients undergoing elective laparoscopic surgery non-invasively and without x-ray exposure. Results of lung ultrasound (LUS) as the experimental method will be compared to the results of Electrical Impedance Tomography (EIT) as the reference technique for the detection of atelectasis. A device for peripheral Oxygen saturation measurement (MASIMO Radical-8) will detect changes in ventilation. The investigators want to confirm or disprove former findings of the appearance of intraoperative atelectases and to prove that ultrasound is a valid tool for detection of atelectases.