ABSTRACT
A nasogastric (NG) tube is a long polyurethane or silicone tube that is passed through the nasal passages through the esophagus into the stomach for delivery of enteral feeds, medication, or aspiration of the gastric contents. It is usually inserted by nurses, junior doctors, and anesthesiologists in the operating room. Nasogastric tubes vary in size from 8 Fr to 18 Fr. A nasogastric tube has various markings that help to determine the length of insertion. There is a radio-opaque marker at the tip to check its position on x-ray. The external measurement from the tip of the nose to a point halfway between the xiphoid and the umbilicus gives a rough idea of the required length of insertion of the nasogastric tube. After its initial insertion, the position of the nasogastric tube must be confirmed by a pH test and an abdominal radiograph. An air insufflation test should not be the sole method of confirming the location of the nasogastric feeding tube. A “pseudoconfirmatory gurgling” sound can be heard on the air insufflation test when feeding tubes are positioned in the tracheobronchial tree or pleural spaces as tubes inadvertently placed in the respiratory tract or esophagus can transmit a sound similar to that of air entry into the stomach.
