Types of tubes
A variety of tubes is used for gastric lavage, aspiration, and decompression. Orogastric tubes (Ewald, Lavacuator®, Edlich) are large-bore tubes with wide proximal outlets for removing gastric contents and are primarily used in emergency departments and intensive care units. The Lavacuator® tube has two lumens, a larger lumen for evacuating gastric contents and a smaller lumen for instilling an irrigant. These tubes are typically kept in place only long enough to complete the lavage and evacuation of stomach contents. Nasogastric tubes are made of various materials (rubber, polyurethane, silicone), with polyurethane the more resistant to deterioration. They also vary in length (90 centimeters to 3 meters [3 to 10 feet]), in size (5 to 20 French), and in purpose.
The most common nasogastric tube is the double-lumen (two-channeled) gastric (Salem) sump tube made of clear plastic and sized according to the French method. This type of tube is useful for irrigating the stomach but is most often used for drawing out fluid and gas from the stomach. In fact, it is the preferred tube for gastric decompression. A major advantage of the gastric sump tube is that it can be used for continuous suction. Sizes 14 to 18 French with a length of 120 centimeters (48 inches) are typical adult sizes. When using this type of tube, connect the larger lumen to suction and collect the aspirated gastric contents in a drainage container.
The smaller second lumen terminates in a blue vent, or “pigtail.” This inner, smaller tube vents the larger suction-drainage tube to the atmosphere via an opening at the distal end of the tube. The blue vent is always open to the air, providing continuous atmospheric air irrigation. A one-way antireflux valve can also be inserted into the blue pigtail to prevent reflux of gastric contents out of the vent lumen. To prevent reflux, keep the tube above the patient’s waist; otherwise, it will act as a siphon. Markings along the length of the tube serve as a guide for the depth of insertion. Both lumens have openings at the tip end to allow for fluid or air flow in and out of the tube. When irrigating the large lumen, inject 20 mL of air into the blue vent to re-establish a buffer of air between the gastric contents and the vent. Never clamp off the air vent, connect it to suction, or use it for irrigation.
The single-lumen (Levin) tube ranges from 14 to 18 French in size. It is made of plastic or rubber with several drainage holes near the gastric end of the tube. It is 125 centimeters (50 inches) long with circular markings at specific points on the tube for monitoring insertion. This nasogastric tube is useful for decompressing the stomach, withdrawing specimens for diagnostic analysis, washing the stomach free of toxic substances, and irrigating the stomach to diagnose and treat upper gastrointestinal bleeding. It can also be used to administer feedings and/or medications. The Levin tube is connected to low intermittent suction (30 to 40 mm Hg) to avoid erosion or tearing of the stomach lining, which can result from constant adherence of the tube’s lumen to the mucosal lining of the stomach.
There are several brands of dual-purpose tubes that can provide simultaneous gastric suction and enteral feeding (Moss Mark IV nasal tube, Dobbhoff nasojejunal feeding and gastric decompression tube). They are inserted nasally and extend into the duodenum or jejunum. When using this type of tube, connect the gastric decompression port to a suction device to aspirate stomach contents. Use the smaller lumen, which extends more distally than the gastric decompression tube, to provide feedings. These tube systems allow for removal of excess feeding formula from the stomach, thereby reducing reflux. Some brands (Moss) include a third lumen that inflates a gastric retention balloon. They range in length from 44 to 67 inches (roughly, 1 to 2 meters) and in size from 16 to 18 French. These tubes are used primarily for patients undergoing surgery.
The Miller-Abbott tube is a 3-meter double-lumen nasointestinal tube with a rubber balloon at the tip of one tube and holes near the tip of the other tube. During insertion, when the tube has passed the pylorus, the balloon is inflated with air. Peristalsis subsequently moves the balloon along the intestinal tract. The contents of the intestines are suctioned through the holes in the tube. The distal end of the tube, which is outside of the patient’s body, has a metal adapter with two openings: one for the suction and one for balloon inflation. It is imperative to label the tube openings so that suction is not applied to the balloon inflation port. This tube is used to sample gastrointestinal fluid and to provide decompression for small bowel obstruction or ileus.
The Sengstaken-Blakemore tube is used to treat upper gastrointestinal bleeding from esophageal varices. It is made of rubber and has two lumens used to inflate the gastric and esophageal balloons, with one tube reserved for gastric suction or drainage. It can be inserted orally or nasally, and endotracheal intubation is strongly advised to secure the airway before insertion. The distal balloon is inflated in the stomach and the proximal balloon is inflated to compress esophageal varices or to reduce gastrointestinal hemorrhage. The Sengstaken-Blakemore tube is a temporary measure for treating upper gastrointestinal bleeding and is usually reserved for emergency settings.
Contraindications to nasogastric tube placement include severe midface trauma, recent nasal surgery, and esophageal perforation. Patients with recent head trauma or brain surgery, deviated septum, esophageal varices or strictures, recent banding or cautery of esophageal varices, coagulation abnormalities, alkaline ingestion, or nasal polyps are at higher risk for complications. The provider must consider the various options carefully for patients who have these conditions.
American Academy of Clinical Toxicology. (2000). Position statement: Gastric lavage. Retrieved May 31, 2008, from http://www.npis.org
Craven, R. F., & Hirnle, C. J. (2007). Fundamentals of nursing: Human health and function (5th ed.). New York: Lippincott Williams & Wilkins. pp. 1139-1145.
Heard, K. (2006). The changing indications of gastrointestinal decontamination in poisonings. Clinics in Laboratory Medicine, 26, 1-12.
Kowalak, J. P. (Ed.). Lippincott’s nursing procedures (5th ed.). New York: Lippincott Williams & Wilkins. pp. 657-670.
Smeltzer, S. C., Bare, B. G., Hinkle, J. L., & Cheever, K. H. (2008). Brunner & Suddarth’s textbook of medical-surgical nursing (11th ed.). New York: Lippincott Williams & Wilkins. pp. 1174-1181.
Smith, S. F., Duell, D. J., & Martin, B. C. (2008). Clinical nursing skills (7th ed.). Upper Saddle River, NJ: Pearson Prentice Hall. pp. 652-662.