Observation of Atelectasis Using Lung Ultrasonography in Children Undergoing General Anesthesia: the Cohort Study for Evaluation of the Relationship Between the Incidence and Severity of Upper Respiratory Tract Infection and the Magnitude of Anesthesia-induced Atelectasis

Pediatric patients between 6months and 6years old will be included. They are scheduled for elective general or urologic surgery at a single tertiary medical center. Before the operation, the researcher interviews the parents of the pediatric patients to check whether they have the upper respiratory tract infection and asks them to fill out a questionnaire about the severity of their symptoms. The researcher will get the symptom score of the upper respiratory tract infection in the questionnaire. The degree of anesthesia induced atelectasis is measured using lung ultrasound. Pulmonary ultrasound is performed after endotracheal intubation and at the end of the operation dividing the patient's thorax into 12 regions. The investigator grades the degree of atelectasis at each region form 0 to 3 points. After the end of the operation, check whether the respiratory adverse effects occurred during emergence and recovery at the post anesthesia care unit.