As nasotracheal intubation, nasogastric tube can cause orophanryngeal colonization and nosocomial sinusitis. By impairing the function of the upper oesophagus sphincter, it may facilitate the reflux of bacteria from the gut. As a result, it increases the risk of VAP [130, 131] . In a randomized study, gastroesophageal reflux and microaspiration of gastric contents to the lower airways were not influenced by the size of the nasogastric tube. Because of their potential complications (tracheal malposition by coiling and clogging) and high cost, the small-bore nasogastric tubes are not routinely recommended for the prevention of VAP [132] .