A nasogastric (NG) tube is a flexible tube placed through the nostril into the stomach, used for delivering nutrition, medication, or removing stomach contents. Aspiration involves gently withdrawing fluid from the tube.
Purpose of NG Tube Aspiration
A primary reason for aspirating an NG tube is to confirm its correct placement within the stomach. Testing the acidity of withdrawn gastric contents (typically pH 1-5.5) helps verify the tube is not mistakenly in the lungs or esophagus. This is important before administering anything through the tube.
Aspiration also helps assess gastric residual volume, the amount of fluid remaining in the stomach. Monitoring this volume helps determine digestive function and prevent overfeeding during continuous tube feedings. Additionally, aspiration can relieve abdominal discomfort by removing excess air or fluid, decompressing the stomach.
Preparing for Aspiration
Before beginning the aspiration process, gather all necessary supplies. You will need a 60 mL catheter tip syringe, fresh gloves, pH indicator strips, a clean container for aspirated fluid, and a towel or disposable pad to protect surfaces.
Thorough hand hygiene is essential before touching any supplies or the patient. Position the individual comfortably, ideally in a semi-Fowler’s position where their head is elevated to a 30-45 degree angle. Ensuring privacy and comfort promotes a more relaxed environment.
Performing the Aspiration
Once prepared, gently uncap the NG tube. Carefully attach the 60 mL catheter tip syringe to the open end, twisting it slightly to ensure a secure connection. This helps prevent leaks and ensures efficient withdrawal of contents.
Slowly pull back on the plunger of the syringe to withdraw stomach contents. Observe the color and consistency of the aspirated fluid; gastric fluid often appears clear, yellowish, or greenish. Continue withdrawing until no more fluid can be easily obtained.
If the purpose is to check gastric residual, note the total volume aspirated. After assessing the aspirate, it is common practice to gently re-instill the collected fluid back into the stomach, unless otherwise instructed, to prevent fluid and electrolyte imbalances. If re-instillation is not indicated, dispose of the fluid properly. After re-instilling or discarding the aspirate, a gentle flush of the NG tube with a small amount of water, typically 10-20 mL, can help clear the tube and prevent clogging. Disconnect the syringe and securely cap or clamp the NG tube.
Post-Aspiration Steps
Following the aspiration, measure the volume of any collected fluid, especially if it was not re-instilled. This measurement provides important information about gastric emptying. Take a small sample of the aspirated fluid and apply it to a pH indicator strip.
Compare the color change on the strip to the provided pH chart; gastric fluid typically shows an acidic pH, confirming the tube’s stomach placement. Document all findings, including the volume, appearance, and pH of the aspirate, as well as the date and time of the procedure. This detailed record is important for ongoing patient care. If tube feedings or medications were paused, resume them as directed by the healthcare provider after these post-aspiration assessments are complete.
Important Considerations and When to Seek Help
Obtaining aspirate can be challenging, or the tube might seem blocked. If no fluid is withdrawn, try gently repositioning the individual or rotating the NG tube, then attempt aspiration again. A gentle flush with a small amount of air or water might also help clear a minor obstruction, but this should only be done if permitted by specific guidelines.
Be aware of warning signs that indicate a potential problem during or after aspiration. These include difficulty breathing, persistent coughing, or any signs of distress. If the aspirate appears like respiratory secretions (e.g., frothy or mucus-like) or if there are significant changes in the volume or appearance of the aspirate, such as new blood, seek immediate medical attention. Always remember that this information provides general guidance, and specific instructions from a healthcare provider should always be followed. Do not hesitate to contact a doctor or nurse with any concerns.