Nasogastric (NG) intubation is one of the commonly performed procedures 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, have 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, intractable nausea and vomiting, intoxication, significant trauma, upper gastrointestinal bleeding, or who are endotracheally intubated. The procedure is rapid, simple, and straightforward.
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. The posterior nasal cavities are continuous with the nasopharynx that develops into the posterior oropharynx as you move caudally (Figure 58-1). The oropharynx continues inferiorly as the esophagus that enters the stomach below the diaphragm.2
Basic anatomy of the path of the NG tube.
The placement of a NG tube in children is often difficult. Their large tonsils and adenoids may hinder the passage. These tissues are soft, easily injured, and may bleed as the NG tube is passed. The tongue, large by comparison with adults, may push into the oropharynx and impede passage of the NG tube. Their nostrils and nasal passage are quite small and limit the size of NG tube that may be passed.
Nasogastric intubation may be performed for diagnostic or therapeutic indications.15 The primary indication for NG intubation is to aspirate stomach contents. It is used to evaluate the presence, rapidity, and volume of an upper gastrointestinal hemorrhage. However, unless the aspirate is grossly bloody, detection of blood may be unreliable. The fecal Hemoccult card should not be used to test for occult blood in gastric aspirates, as it may be accurate. The Gastroccult card uses a developer that neutralizes gastric acid, rendering it able to detect hemoglobin.11 A NG tube may be inserted to instill air into the stomach to assess for an intraperitoneal perforation. Gastric fluid and contents may be aspirated for laboratory analysis. It may also be placed to visualize the stomach on chest radiography to assess for a diaphragmatic hernia. A NG tube is placed in patients for medication administration, relief of a bowel obstruction, treatment of recurrent vomiting, administration of oral contrast for diagnostic imaging, and to perform gastric lavage. They are placed to decompress the stomach preoperatively, postintubation, prior to a diagnostic peritoneal lavage, or prior to a pericardiocentesis.
Absolute contraindications do not exist for NG tube placement. The relative contraindications are geared toward predicting which patients are more likely to experience complications ...