Abstract: 57-year-old male was admitted to hospital for severe headache and seizure attacks on November 6th, 2016. After radiology and spinal fluid examination, he was diagnosed with viral encephalitis and treated with antiviral medicine, antibiotics and mannitol, but he was in sustained unconsciousness and weak in expectorating. The patient was given oxygen through artificial nasal after bedside tracheotomy.  At 1:00 am on January 12th, 2016, there was a sudden drop in blood pressure, heart rate and oxygen saturation with left lung breath sounds slightly lower than the other side. The patient was connected to a ventilator with tidal volume of 300-500 mL and airway pressure of 16-24 cmH2O (1 cmH2O=0.098 kPa). In the meanwhile, the left side sponge of artificial nasal was found missing. Bedside chest X-ray showed no significant atelectasis. At that time the evidence of airway foreign body aspiration was not sufficient, so no urgent bronchoscopy was performed. At 9:00 am on January 14th, 2016, there was another sudden decline in oxygen saturation with diminished left lung breath sounds and decreased left thoracic activity. Since left atelectasis could not be ruled out, bedside bronchoscopy was performed. In the operation, two spongelike objects were found at the left main bronchus and the opening of left upper lobe bronchial. Foreign body forceps were used to remove them. The foreign bodies were proved to be the left sponge of artificial nasal afterwards. Symptoms and signs caused by aspiration of foreign body in adults were widely various and depending on the nature of the foreign body, site, time and whether there was infection or not. Foreign body aspiration caused by artificial nasal sponge was rare in clinical practice. This case was a living reminder to perform bronchoscopy when foreign body aspiration was suspected. For the unconscious and elderly patient, whose history of foreign body aspiration usually could not be clearly provided, when atelectasis was suspected, bronchoscopy should be performed progressively, and more effective measures should be taken to prevent sponge of artificial nasal displacement.

Key words: Bronchi, Foreign bodies, Airway obstruction, Bronchoscopy, Respiratory aspiration