Silent laryngeal penetration or silent aspiration (SLP/SA) was observed in four patients. During the follow up period, three of the four patients with SLP/SA developed respiratory infection, and one of the 13 patients who did not show SLP/SA had airway infection (RR=9.75, 95% CI: 1.36-69.65). Two patients with SLP/SA developed airway infection and died, and there were two deaths in the group who had not been diagnosed for SLP/SA, one due to cardiac arrest and the other related to pancreatic cancer.