The structure and function of a feeding tube

A feeding tube is a common term for an enteral nutrition tube, which mainly refers to a medical catheter used to directly deliver nutrients into the gastrointestinal tract. It is similar to the gastric tube introduced earlier in its core purpose, but there are some differences in placement location, tube diameter, and applicable scenarios.

Feeding tubes are typically made of medical-grade polyurethane or silicone, which are soft, biocompatible, and can be left in place for extended periods. They consist of the following key structures:

• Slender tube: Slender and longer than a standard gastric tube, with depth markings on the surface. The front end is usually closed, with a side opening for the drainage of the nutrient solution.

• Guidewire: Most models have a built-in removable guidewire (guide wire) to increase rigidity and facilitate passage through the pylorus into the duodenum or jejunum. It must be withdrawn immediately after placement.

• Radiopaque line: An X-ray radiopaque line is embedded in the tube wall, allowing the tip position to be confirmed via imaging after insertion.

• External connector: The tail end connects to a standard enteral nutrition connector, compatible with a nutrient pump or syringe. It usually features a misconnection prevention design to avoid confusion with intravenous infusion lines.

Its core function is to bypass the mouth and upper esophagus, providing a direct nutritional pathway to the gastrointestinal tract for patients unable to eat orally.

1. Enteral Nutrition Support: Delivering customized nutritional solutions (such as whole protein, short peptide, or disease-specific solutions) into the gastrointestinal tract to maintain the patient's nutritional status and intestinal mucosal function, preventing intestinal villus atrophy caused by prolonged fasting.

2. Reduced Risk of Reflux and Aspiration: Compared to ordinary gastric tubes (with the end in the stomach), nasoenteric tubes (with the end in the duodenum or jejunum) significantly reduce the risk of reflux of nutritional solutions into the esophagus and aspiration into the lungs, making them particularly suitable for patients with swallowing dysfunction, altered mental status, poor gastric motility, or severe pancreatitis.

3. Drug Infusion and Drainage: Some models also function as gastrointestinal decompression devices, which can be used for drug infusion or drainage when necessary.

Nasogastric Tube:The distal end is located in the stomach. The tube diameter is relatively large, making insertion easier. Suitable for patients with normal gastrointestinal function and no high risk of reflux or aspiration.

Nasoenteric Tube:The distal end is located in the duodenum or jejunum. The tube diameter is even smaller, requiring endoscopic, X-ray guidance, or spontaneous insertion through the pylorus with the aid of gastric motility. Suitable for patients with impaired gastric emptying, severe reflux, high risk of aspiration, or severe pancreatitis.

Before each infusion of nutrient solution after tube insertion, the position of the tube must be strictly confirmed. For nasoenteric tubes, X-ray is usually the gold standard for confirming the position; for nasogastric tubes, methods such as aspirating gastric fluid to measure pH and auscultating for gurgling sounds are used. It is strictly forbidden to connect the feeding tube to intravenous infusion lines. Accidentally injecting nutrient solution into the airway or vein can lead to fatal complications.