[Hypoxemia after gastrointestinal endoscopy under general anesthesia in a patient with unilateral diaphragmatic paralysis].

A 59-year-old woman with suspected hypopharyngeal cancer was scheduled for biopsy using direct laryngoscopy. Her preoperative chest X-ray showed asymptomatic left unilateral diaphragmatic paralysis. Anesthesia was induced with propofol and maintained with oxygen, nitrous oxide and sevoflurane. The region was difficult to reach during direct laryngoscopy. Therefore, gastrointestinal endoscopy was performed. Air was injected through the scope to aid viewing. After tracheal extubation, oxygen saturation as indicated by pulse oximetry (SpO2) decreased to 91% from 97% although oxygen was delivered via a mask at 6 l x min(-1). A chest radiograph showed that the air-filled gastrointestinal tract had elevated the left dome of the diaphragm. After the stomach was suctioned via a nasogastric tube, respiration was assisted via a mask with continuous positive airway pressure. Then, SpO2 returned to 99%. An air-filled dilated stomach may increase the risk of respiratory dysfunction in patients with unilateral diaphragmatic paralysis.