Nasogastric (NG) intubation is a commonly performed procedure in the Emergency Department.1 Its use as a conduit into the stomach was first popularized in the early twentieth century mainly through the efforts of Dr. Levin. Clinicians have since studied its use, proposed methods to improve the ease with which the NG tube is inserted, and determined ways to diminish the incidence of potentially lethal complications. A NG tube is often placed in patients who have a bowel obstruction, intoxication, intractable nausea and vomiting, significant trauma, or upper gastrointestinal (GI) bleeding or who are endotracheally intubated. The procedure is rapid, simple, and straightforward. The insertion of an NG tube is slowly decreasing.2-7
ANATOMY AND PATHOPHYSIOLOGY
The nasal cavity is lined by the very vascular nasal mucosa. The medial wall of the nasal cavity is composed of the septum. The lateral wall of the nasal cavity is covered by the turbinates or concha. The posterior nasal cavities are continuous with the nasopharynx that develops into the posterior oropharynx caudally (Figure 75-1). The oropharynx continues inferiorly as the esophagus that travels through the esophageal hiatus in the diaphragm and enters the stomach.8
Basic anatomy of the path of the NG tube.
Pediatric nasopharyngeal anatomy differs from that of adults and can result in a more difficult NG tube insertion. The nostrils and nasal passages of children are quite small and limit the size of NG tube that may be passed. Children have relatively large tonsils and adenoids, which may hinder passage of the tube. The nasal tissues are often soft, easily injured, and may bleed as the NG tube is passed. The tongue is large by comparison with adults and may push into the oropharynx and impede passage of the NG tube.
NG intubation may be performed for diagnostic or therapeutic indications.2 The primary indication for NG intubation is gastric decompression. This may help relieve a bowel obstruction, volvulus, or recurrent vomiting (e.g., pancreatitis). NG tubes are placed to decompress the stomach preoperatively, postintubation, or prior to a procedure (e.g., diagnostic peritoneal lavage or pericardiocentesis).
An NG tube may be placed for diagnostic purposes. A diagnostic indication for NG tube placement is to aspirate stomach contents to evaluate the presence, rapidity, and volume of an upper GI hemorrhage. The detection of an upper GI bleed may be unreliable via this technique.4 Do not use the fecal Hemoccult card on gastric aspirates to test for occult blood in gastric aspirates. A Hemoccult card may be inaccurate due to gastric aspirate acidity. The Gastroccult card uses a developer that neutralizes gastric acid and renders it able to detect hemoglobin.9,10 An NG tube may be inserted to instill air ...