Polysomnographic assessment of respiratory disturbance during deep propofol sedation for endoscopic submucosal dissection of gastric tumors

Figure 3 Typical polysomnograph of an obstructive hypopnea that occurred during endoscopic submucosal dissection under propofol sedation. Obstructive hypopnea episodes were diagnosed based on paradoxical thoraco-abdominal wall movements and flattened nasal pressure waves and resolved spontaneously with gradual increase in airflow caused by an increase in breathing effort.