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Nasogastric Tubes

Snapshot: This document provides an overview of nasogastric tubes, along with clinical indications, contraindications, steps for insertion and removal, NG tube care, and use with medications and feedings. Also included is a brief library of video links that demonstrates how to perform this skill.

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Instructional Videos for Nasogastric Tubes Nasogastric Tubes: An Overview Clinical Indications, Limitations and Considerations for Nasogastric Tubes Contraindications and Complications for Nasogastric Tubes Inserting a Nasogastric Tube Removing a Nasogastric Tube NG Tube Care Administering Medications & Feedings

Instructional Videos for Nasogastric Tubes

Nasogastric Tubes: An Overview

  • Nasogastric tubes (NG tubes) are flexible plastic tubes, usually polyurethane or silicone, that carry food or medicine through the nose and down into the stomach, or from the stomach out through the nose.
  • It is within an RN’s scope of practice to place, monitor and maintain a nasogastric tube, although most facilities require a physician order to initiate or discontinue an NG tube, or to change the type of feeding administered via an NG tube.
  • Patients get NG tubes for two primary reasons:
    • To remove gastric secretions (drain the stomach)
      • These patients may have gastrointestinal obstructions (for example, due to cancer), or may have NG tubes inserted immediately after major surgery to help keep the stomach empty and prevent post-operative emesis. NG tubes may also be used to aspirate (i.e. drain) the stomach in case of a gastrointestinal (GI) bleed, or in the case of poisoning or a drug overdose.
    • To administer food or medicine to patients who have difficulty swallowing (i.e. dysphagia) or who are unable to swallow
      • This may include, for example, patients who recently experienced a stroke, or who underwent a tracheostomy (a surgical procedure to create an opening into the trachea, or wind pipe), and who have lost control of their swallowing muscles. Critically ill patients who require assistance with feeding or medication administration may also have an NG tube placed.
  • There are two main type of NG tube
    • The Levin Tube
      • The Levin Tube is a flexible, soft rubber or plastic tube with a single lumen (i.e. tube) and holes at the tip and along the distal side. It’s used for decompression (reducing pressure in the stomach), lavage (washing out the stomach), or feeding, but not for suctioning (emptying the stomach) because it could adhere to and irritate the stomach’s mucosal surface.
    • The Salem Sump
      • The Salem Sump tube has two lumens; the second, smaller lumen serves as an air vent (also called a sump port or ‘pigtail’) that allows atmospheric air to continually flow into the stomach. This prevents the tip of the NG tube from adhering to the lining of the stomach, which makes it ideal for suctioning (emptying the stomach).

Clinical Indications, Limitations and Considerations for Nasogastric Tubes

  • Nasogastric tubes are primarily intended for short-term use, typically for 48 – 72 hours.
  • Patients who require feeding or medication administration via an NG tube for longer than 48 – 72 hours should consider getting a percutaneous endoscopic gastrostomy, or PEG tube, which is a tube that goes directly into the stomach.
  • Nasogastric tubes may be placed for prophylactic or therapeutic reasons (that is, to prevent problems from occurring, or to fix problems that already exist).
  • Nasogastric tubes can also be used for diagnostic purposes, since it is possible to collect gastric contents using an NG for laboratory analysis.
  • Nasogastric tubes can be used to aspirate (suction or extract) stomach contents, or to administer food or medication on a continuous or intermittent basis.
    • It is often dangerous to suction gastric contents on a continuous basis, since this can easily damage the lining of the stomach. Continuous suctioning is therefore usually only indicated for emergency situations. In non-emergent situations, intermittent suction or gravity suction is used.
    • Continuous feeding via NG tubes is usually accomplished via an automated pump. Such continuous NG feeds present a risk of aspiration in patients, and must be closely monitored.

Contraindications and Complications for Nasogastric Tubes

  • Nasogastric tubes are contraindicated in patients with any of the following conditions:
    • Basal skull fractures and/or severe facial fractures (especially to the nose and esophagus)
    • Esophageal varices (enlarged sub-mucosal veins in the lower third of the esophagus)
    • Obstructive airways disorders (such as COPD)
    • Patients who have undergone gastric bypass surgery, i.e. surgery to reduce the size of the stomach for weight loss
  • Complications of nasogastric tubes may be minor or major
    • Minor complications include nose bleeds, sinusitis (inflammation of the paranasal sinuses), and sore throats.
    • More significant complications include erosion of the tube where the tube is anchored, esophageal perforation, pulmonary aspiration, a collapsed lung, or intracranial placement of the nasogastric tube.
    • Note: If the NG tube’s output is excessive, it may have inadvertently been placed too far down, possibly in the duodenum (the first section of the small intestine), which lies immediately beyond the stomach. If this is so, it should be removed and a new NG tube correctly re-inserted.

Inserting a Nasogastric Tube

  • Your first step in inserting an NG tube is to gain informed consent. The patient should be given an explanation of the insertion procedure, and should know why the tube is necessary. Follow your institution’s guidelines for obtaining verbal or written consent, and document what you have done.
  • Practice universal precautions and wash your hands with soap and water. While inserting a nasogastric tube is not a sterile procedure, you can reduce the risk of transmission of bacteria and other pathogens with hand washing.
  • The next step is to select an appropriately sized NG tube, and gather your needed supplies. NG tubes come in a variety of sizes, and are measured via the French scale (Fr). Most NG tubes range from 8 – 18 Fr in diameter, and are 42 – 50 inches in length. The supplies you’ll need include the NG tube, gloves, some anesthetic jelly or lubricant, a glass of water, a towel, some tissues, some tape, an emesis basin, and possibly a pH strip. Note: especially for less experienced nurses, it is often helpful to bring another nurse with you to help you “coach” the patient as you insert the NG tube, and to support you if you require guidance.
  • To determine the length of tubing you’ll need, straighten the tube between your hands, and measure from the tip of the patient’s nose, then loop the tube around the patient’s ear, bringing the tube to roughly 5 cm below the xiphoid process (a small tip of ossified cartilage at the end of the sternum). This should be roughly equidistant between the end of the sternum and the umbilicus.
  • Either note or mark this spot on the NG tube. Many tubes have inch or centimeter marking pre-printed on the tubes. It is important to remember this number because you need to know how far down to place the tube when you insert it. The average length of tubing you’ll insert for an adult is from 22 – 26 inches.
  • If the tube doesn’t have a natural bend in it, put on some gloves and coil the end of the tub around your index finger to create a natural curve to make insertion easier.
  • Next, lubricate the distal end of the NG tube, preferably with a local anesthetic, such as 2% xylocaine gel. Plain lubricant is another option if xylocaine gel is unavailable. You should coat 2 – 4 inches of the curved end of the tube with lubricant. Avoid oil-soluble lubricants such as petroleum jelly, as this may damage the NG tube and is poorly tolerated by the pulmonary mucosa.
  • Help you patient into a high Fowler’s position, and cover his or her chest with a towel. To determine which nare through which to insert the NG tube, ask the patient to occlude one nostril at a time with his or her fingers and breathe. Whichever nostril has better airflow is the one you should use to insert the NG tube. Make sure the glass of water, tissues and emesis basin are within reach.
  • Next, help the patient to relax, insert the tube through a nostril and direct it straight towards the back of the patient’s throat. When the tube hits the back of the patient’s throat, i.e. as the tube moves past the pharynx and begins to enter the esophagus, the patient may begin to gag. If this happens (and it almost always does), ask the patient to sip a small amount of water through a straw, or to swallow as if drinking, as you slowly but deliberately advance the tube in a downward-and-backward direction. (Encouraging the patient to do this will help the trachea to close to ensure the tube goes down the esophagus and into the stomach). Advance the tube when the patient swallows, and pause when you notice the patient breathe. Provide tissues as the patient’s eyes may tear or water.
  • If the patient continues to cough or choke and cannot speak, carefully withdraw the tube just a bit as it may have accidentally entered the trachea. Allow the patient to rest for a moment before beginning to advance the tube again. If after several attempts and despite encouraging your patient you remain unsuccessful, stop and notify your supervisor and/or the physician who ordered the NG tube. While it is rare, some patients are simply too sensitive or too frightened to tolerate an NG tube. In most cases, once you ’round the bend’ of the oropharynx and begin to move the tube down the esophagus, the patient’s discomfort should decrease.
  • Once you have advanced the tube to the point you noted or marked, secure it with some paper tape, or with a bandaid. One trick is to cut a slit in the bandaid or tape, and use the two ‘wings’ of the resulting bandage to wrap around the tube on either side of the patient’s nose.
  • Once you have secured the tube, you must verify proper placement. The gold standard for verification is to use some pH paper to verify placement. If the pH is 5.5 or less, you know the tube is placed in the stomach (since gastric contents are acidic). An X-ray may also be used to verify proper placement (the tip of the tube will appear as a white radio-opaque line, and should be below the diaphragm on the left hand side of the film). Alternative, but not definitive, means of verification are to use a large, empty syringe to inject air into the tube, and listen for a gastric ‘bubble.,’ i.e. the sound of air when a stethoscope is placed on the stomach. If this technique is used, many organizations require that two RN’s independently verify proper NG tube placement; others don’t permit the use of this technique. Make sure you know and follow your organization’s rules and regulations.
  • Next, secure the tube to the patient’s gown by using a rubber band or tape and a safety pin. If double-lumen tube is used, secure the vent above stomach level. If the NG tube is being used for continuous drainage, it should usually be attached to a collecting bag below the level of the patient’s stomach; gravity can then empty the stomach. The NG tube can also be connected to a suction system for intermittent suction, or in emergency situations, continuous suction.
  • When you are finished, document what you have done, including the type and size of NG tube used, how the patient tolerated the procedure, and if indicated a description of the gastric contents.

Removing a Nasogastric Tube

  • Removing an NG tube is relatively simple. First, you need to loosen and remove the bandage from the patient’s nose holding the tube in place. One trick is to use an alcohol pad or a bit of mineral oil to dissolve the glue on the underside of the tape or band-aid.
  • Next, help the patient to a high Fowler’s position and put a towel across his or her chest. If any suction has been in use, turn it off. If a drainage bag has been in use, disconnect it.
  • Ask the patient to take a breath and hold it in. In one smooth motion, remove the tube.
  • The patient may cough as the tube passes the pharynx. Have a glass of water handy to offer the patient after the tube has been removed, for comfort.
  • Wrap the tube in the towel, and dispose of it according to your organization’s guidelines.
  • Document what you have done, including how the patient tolerated removal of the NG tube.

NG Tube Care

  • Daily care for an NG tube should involve gently cleaning around the tube with mild soap and water, or whatever protocol your organization specifies.
    • You can use a cotton swab moistened with warm water, or coated with a water soluble lubricant such as KY jelly. Avoid oil-based lubricants such as Vaseline as this can corrode plastic tubing. When you are finished, be sure to gently dry the tube as a moist NG tube can lead to bacterial growth and skin breakdown.
  • Good oral hygiene – especially brushing teeth at least twice per day – is also critical, and is associated with fewer NG tube complications and lower rates of infection. This is because good oral hygiene helps fight oral bacteria, which can easily enter the body through the mouth.
  • While it is common sense, patients should take care to not pull or sit on the NG tube. It can be easy to forget to mind an NG when performing other nursing functions, or when turning or moving a patient.
  • It is also important to always note the length of the NG tube. Most NG tubes have external markings. When an NG tube has been moved or dislodged, it is often visually apparent.
    • Note: if the NG tube becomes dislodged you need to obtain a physician order to reinsert it.
  • To prevent skin breakdown, it’s good practice to un-tape and rotate the NG every day or two to a slightly different position within the nostril. You can moisturize the skin with a fragrance-free lotion or cream and let it air dry before re-taping the tube in place again. Be careful to only rotate the tube, and not to change its length as this could alter its placement in the stomach.

Administering Medications & Feedings

  • Not all medications can be safely administered via an NG tube.
    • In general, it is usually safe to administer liquids, immediate-release oral tablets, and (when the contents have been punctured and drained into the tube), soft gelatin capsules.
    • It is not usually safe to administer extended release or enteric coated tablets, sublingual or buccal medications, or syrups via an NG tube.
    • When in doubt, contact a pharmacist. He or she will be able to instruct you on which medications can be safely given via an NG tube and which cannot.
  • To avoid drug interactions when giving medications, give 30 cc of water between medications. Unless specifically approved, medications should not be mixed with formula or feedings, because medications can adversely interact with certain ingredients.
  • When feeding a patient using an NG tube, first ensure that he or she is sitting upright at least 45 – 60 degrees in bed. The patient should remain in that position during the entire feeding, and for at least 30 minutes following the feeding. Failure to do this may lead the patient to aspirate.
  • Orders for NG tube feedings should specify several important details: the type of feeding, the amount (usually in milliliters), the frequency of the feeding, how much free water should be used to flush the tube, and how much residual (i.e. fluid that remains in the stomach since the last feeding) can remain. Physicians (especially younger residents) may be unclear about this, or may write incomplete orders; make sure you know what the order specifies before you administer a feeding.
  • Use a large plastic syringe (30 – 60 cc’s) to administer the feeding. One useful trick is to pre-mix the feeding with some water (depending upon how much free water flush is permitted), and then use some additional free water to flush the tube at the conclusion of the feeding. Many NG tube feedings are thick and will get clogged in the tube without using this approach. For patient comfort, use room temperature water. Using cool water will cause gastric cramping.
  • Check for proper NG tube placement using your organization’s guidelines before initiating the feeding. You should do this before every feeding, not just every 24 hours. Then, check for gastric residual by uncapping the NG tube, affixing the syringe, and pulling back. Always replace gastric contents by pushing back on the syringe again; do not discard gastric contents unless specifically ordered to do so.
  • Always use gravity to administer the feeding; never force the feeding by using a syringe. Place the feeding higher than the patient’s stomach and let it drain in. And of course, don’t forget to re-cap the NG tube when you’re finished.