A nasogastric (NG) tube is a flexible tube inserted through the nose, down the esophagus, and into the stomach. This temporary medical device serves as a direct pathway for delivering nutritional support, liquid formula, or medications when a person cannot safely eat or swallow. NG tubes are also used for gastric decompression, which involves removing air or fluid from the stomach to relieve pressure, such as in cases of bowel obstruction. The continued functionality of this tube depends on a routine procedure known as flushing.
Why Flushing NG Tubes is Necessary
The primary reason for routine flushing is to maintain tube patency, ensuring the internal pathway remains open and clear for the passage of liquids. Without regular maintenance, the tube can easily become clogged by the residue of feeding formulas or certain medications. A blockage stops the delivery of necessary nutrition and therapeutic drugs, potentially leading to serious health complications.
Flushing also contributes to the patient’s overall daily fluid intake, aiding in hydration. Clearing the tube with water between different medications is important for preventing unintended drug-to-drug interactions. Certain liquid medications can react with residual formula, sometimes forming a precipitate that quickly creates a blockage. This maintenance step ensures the patient receives the full, intended dose.
Step-by-Step Guide for NG Tube Flushing
Before beginning the flush, gather the necessary supplies, including a 30 mL or 60 mL enteral syringe and the prescribed amount of water, which should be warm or at room temperature. The first step involves verifying the tube’s correct placement in the stomach. This is often done by checking the centimeter marking at the nostril and confirming the pH of a small aspirate of stomach fluid. Never administer anything through the tube without confirming its position, as incorrect placement could lead to liquids entering the lungs.
Once placement is verified, draw the prescribed volume of water into the syringe, which is typically 30 mL, or 15–30 mL between individual medications. Connect the tip of the syringe to the port of the NG tube, ensuring a secure connection. Gently push the plunger to instill the water, using a steady, slow pressure.
If you encounter resistance, stop immediately; forcing the water can damage the tube or cause injury. Use the “push-pause” method, where you push a small amount of water, pause briefly, and then repeat until the full volume has been administered. After the flush is complete, disconnect the syringe and close the port cap, avoiding drawing air into the stomach, which can cause bloating. The volume of water used for the flush must be documented as part of the patient’s fluid intake record.
Establishing a Flushing Schedule
The specific timing and frequency for flushing an NG tube depend on how the tube is being used, but the core principle is to flush before and after use.
Intermittent and Bolus Feedings
If the patient is receiving intermittent or bolus feedings, the tube must be flushed immediately before and after each session. This clears the tube prior to the feed and removes all formula residue afterward.
Medication Administration
When administering medications, a flush is required before the first medication. A smaller flush volume (15 mL to 30 mL) is required between each separate drug. A final, larger flush is performed after the last medication to completely clear the tube.
Continuous Feedings and Maintenance
For continuous feedings, where formula runs through a pump, the tube should be flushed every four to six hours to maintain patency. Even if the tube is not actively being used, a maintenance flush is necessary at least once every eight hours to prevent the inner walls from drying out. The exact volume and frequency of flushes should always be determined by a healthcare provider, and their instructions must be followed precisely.
Recognizing and Managing Blockages
A tube blockage is indicated by an inability to push fluids or medications through the tube, or by encountering significant resistance during a routine flush. The first response to a suspected clog is to stop the feeding or medication administration immediately. Check the outside of the tube for any kinks or external pressure points that could be causing the obstruction before attempting to clear the blockage.
To address a minor clog, fill a 30 mL or 60 mL syringe with warm water and attach it to the tube. Gently push and pull the plunger in a repetitive motion, creating a small amount of pressure and vacuum to try and dislodge the material. If the initial attempts with warm water fail, certain specialized declogging solutions, such as a mixture of pancreatic enzymes and sodium bicarbonate, may be prescribed by a healthcare provider.
It is important to never use excessive force on the syringe, as this can rupture the tube or cause it to migrate out of position. Avoid using sharp objects or guidewires to clear the tube, as they can cause irreversible damage. If the blockage cannot be cleared after a few gentle attempts, or if the patient experiences any distress, contact the healthcare team immediately, as the tube may need professional intervention or complete replacement.