Effects of Spontaneous Breathing Activity on Atelectasis Formation During General Anaesthesia

Atelectasis and redistribution of ventilation towards non-dependent lung zones are a common side effects of general anesthesia. Spontaneous breathing activity (SBA) during mechanical ventilation may avoid or reduce atelectasis, improving arterial oxygenation; however, it is unclear whether these effects play a significant role during general anesthesia in patients with healthy lungs. Earlier studies on ventilation during general anesthesia had to rely on computed tomography (CT) findings. Recent advances in lung imaging technology allow to assess the regional aeration of the lungs continuously and non-invasive by electrical impedance technology (EIT). In this work, we will use the EIT to assess ventilation changes from the time before induction of anesthesia until discharge from the post-anesthesia care unit. Our main focus is the difference caused by pure positive pressure ventilation (PCV) and assisted spontaneous breathing (pressure support ventilation, PSV). Our findings would improve our understanding of the physiology of the lungs during general anesthesia and would help to improve the standards of respiratory care during anesthesia