A nasogastric (NG) tube is a thin, flexible tube inserted through the nose, down the esophagus, and into the stomach. Its function is to provide nutrition, fluids, or medication directly to the stomach for individuals who cannot safely consume them orally, often due to difficulty swallowing. Safe and effective medication delivery through this route requires following precise, standardized steps. Proper administration involves careful preparation, drug conversion, delivery technique, and post-procedure care to maintain patient safety and tube patency.
Essential Preparation and Safety Checks
Preparation begins with assembling the necessary supplies, including the prescribed medication, a 60 mL enteral syringe, a cup for mixing, and at least 30 mL of room-temperature water for flushing. Thorough hand hygiene must be performed before touching any equipment or the patient. The individual must be positioned correctly, with the head of the bed elevated to a minimum of 30 to 45 degrees, to reduce the risk of aspiration.
The most important safety check is verifying the NG tube’s correct placement in the stomach before administering anything. Placement is often checked by comparing the external length of the tube at the nostril to the documented insertion length. A more definitive method involves aspirating fluid and testing its pH level using indicator strips.
A gastric aspirate pH of 5.5 or below suggests the tube is correctly positioned. If the pH reading is higher than 5.5, or if no fluid can be aspirated, the tube position must be re-evaluated and corrected. This placement check must be confirmed every time the tube is accessed for medication or feeding.
Converting Medications for Tube Delivery
Most solid medications must be converted into a liquid form to pass safely through the narrow NG tube and prevent clogging. This requires crushing non-coated tablets into a fine powder using a pill crusher. The powder is then completely dissolved in warm water, typically at least 30 mL per medication, to create a smooth suspension that can pass through the tube.
Certain medication forms must never be altered or administered through an NG tube because crushing them destroys their intended action. These include extended-release (ER, XR, LA), sustained-release (SR), and controlled-release (CR) formulations, which release the drug slowly over time. Crushing these can lead to “dose-dumping,” causing a sudden, harmful release of the entire dose.
Enteric-coated tablets should not be crushed, as they are designed to bypass the stomach and dissolve in the intestine. Crushing exposes the drug to stomach acid, decreasing effectiveness or causing irritation. Sublingual or buccal tablets must also be administered by their intended route, not via the tube. When a solid form is contraindicated, the healthcare team must be consulted to request an equivalent liquid formulation or an alternate route.
Liquid medications are generally suitable for administration, but thick syrups should be diluted with 30 to 60 mL of water to reduce viscosity and the risk of tube blockage. Each medication dose must be prepared separately in its own cup and syringe. Mixing different medications can cause chemical interactions, leading to precipitation, coagulation, or drug binding that will clog the tube.
The Administration Process
Before introducing any medication, the NG tube must be flushed with 15 to 30 mL of water to ensure the tube is patent and clear. This initial flush confirms the tube is not obstructed and prepares the line for medication delivery. The water is administered using the 60 mL syringe, often by removing the plunger and allowing the fluid to flow via gravity, or by applying gentle pressure.
The prepared liquid medication is poured into the barrel of the syringe, connected to the tube, and allowed to flow slowly by gravity. If the flow is too slow, gentle, intermittent pressure may be applied with the plunger. Excessive force must be avoided to prevent tube rupture or patient discomfort. The syringe should be held high enough for gravity to work efficiently, but not so high that air is introduced into the stomach.
If multiple medications are prescribed, each must be administered individually, separated by a water flush of 5 to 15 mL to clear the tube and prevent drug interactions. This sequence is repeated until all doses are delivered. After the final medication, a generous flush of 30 to 60 mL of water is performed to ensure all drug residue is cleared from the tube and the full dose has reached the stomach.
If the patient is receiving continuous tube feeding, the infusion must be paused before medication administration. The pause time varies, but feeding is typically stopped for at least 30 minutes before and after administering medications. This is necessary for drugs that require an empty stomach or are incompatible with the formula. The interruption prevents the feeding formula from interfering with drug absorption or causing coagulation within the tube.
Post-Delivery Care and Addressing Complications
After the final water flush, the NG tube port should be capped or clamped securely to prevent air entry or reflux of gastric contents. The head of the bed elevation, which was at a minimum of 30 degrees during the process, must be maintained for at least 30 to 60 minutes following administration. This continued elevation minimizes the risk of aspiration.
The total amount of water used for flushing should be accurately recorded as part of the patient’s fluid intake. Medication administration must also be documented in the medical record, noting the time, the drugs given, and the patient’s tolerance of the procedure.
A common complication is tube clogging, indicated by resistance when flushing or delivering medication. If a clog is suspected, the first action is to try a gentle push-and-pull motion with the syringe plunger using warm water to dislodge the obstruction. The patient’s position may also be adjusted, as this can sometimes change the tube tip’s location and improve flow.
Signs of patient intolerance, such as coughing, gagging, difficulty breathing, or vomiting, require immediate attention and cessation of the procedure. Such symptoms may signal tube dislodgement into the airway or an inability to tolerate the volume. Any persistent difficulty, signs of respiratory distress, or inability to clear a blockage necessitates immediate contact with a healthcare professional.