A nasogastric tube, commonly known as an NG tube, is a flexible plastic conduit temporarily inserted into the body for medical purposes. The term “nasogastric” describes the tube’s route, which begins at the nose, passes through the back of the throat and esophagus, and ends in the stomach. This device provides a non-surgical way to access the stomach and is a frequent intervention in hospital settings. NG tubes vary in diameter and material, with different types designed for specific functions.
Core Functions and Medical Applications
The NG tube serves two primary therapeutic purposes. One application is for nutritional and medication delivery, often called enteral nutrition. This method is used when a patient cannot safely or effectively swallow food or liquids due to conditions like stroke, head and neck cancer, or altered consciousness. Liquid formula and medications are passed directly into the stomach, ensuring the patient receives necessary calories and treatment.
The tube’s other function is gastric decompression, which involves removing substances from the stomach. In cases of bowel obstruction or ileus, the gastrointestinal tract can accumulate contents, leading to painful distension and pressure. Connecting the NG tube to continuous or intermittent suction relieves this buildup and helps the digestive system rest. Specialized decompression tubes, such as the Salem Sump, use a double lumen design, where one channel allows for suction and the other acts as an air vent to prevent the tube from adhering to the stomach lining.
The Procedure for Placement
NG tube insertion is a common procedure performed at the bedside. The process begins with measuring the length of the tube needed to reach the stomach. This is done by extending the tube from the tip of the nose to the earlobe, and then down to the xiphoid process (the bottom of the breastbone). This measurement is marked on the tube to guide the clinician during insertion.
The tip of the tube is lubricated with a water-soluble gel to reduce friction as it enters the nasal passage. The tube is gently advanced through the chosen nostril, aiming back toward the ear. As the tube passes the nasopharynx, the patient is asked to tuck their chin and swallow water or dry-swallow to help the tube move past the opening of the windpipe and into the esophagus. This swallowing action uses the epiglottis to close off the trachea, guiding the tube safely toward the stomach.
Once the tube is inserted to the pre-measured mark, correct placement must be verified before any feeding or medication is administered. The most reliable method is obtaining an X-ray to visualize the tube’s tip in the stomach. Clinicians may also check the acidity (pH) of fluid aspirated from the tube, as gastric contents are highly acidic, typically with a pH of 5.5 or lower. The tube is then secured to the nose with specialized tape to prevent accidental dislodgement.
Daily Life and Care
Living with an NG tube requires attention to daily maintenance. The tube is secured to the bridge of the nose and sometimes the cheek with tape or a securing device. This adhesive must be checked and often changed daily to prevent skin irritation. Patients may experience common side effects such as a persistent sore throat, nasal dryness, and irritation from the tube’s presence.
Maintaining oral hygiene is important, as the tube can cause mouth dryness. The tube itself must be flushed regularly before and after use to prevent the thick liquid feeds or crushed medications from clogging the narrow lumen. The external length of the tube is also routinely measured to quickly identify if it has shifted or become dislodged from the stomach.
When the medical need for the tube is resolved, the removal process is straightforward and quick. The securing tape is removed, and the tube is pinched or clamped to prevent any remaining stomach contents from dripping out. The patient is instructed to take a deep breath and hold it, which helps close the airway, and the tube is then gently withdrawn. After removal, the medical team cleans the nose, and the patient can resume normal oral intake as authorized by their physician.