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newSchoolWorks.com › VoTechWorks › Health & Personal Services › Practical Nursing (LPN) › Clinicals: Supervised Patient Care Skills › Lesson 9
HLT-LPN37-06 · Lesson 9 · 14 clock hours · demo

Nasogastric Tube Insertion, Feeding, and Medication Administration

Objective. Students will demonstrate NG tube insertion on a simulation mannequin, verify placement using accepted bedside methods, administer a simulated tube feeding, and safely give a medication via the tube.

⚠ Pending professional review

This lesson, its worked examples and its practice questions has not yet been verified by a licensed clinician in the field or by a certification or approval body. It is a study draft and may contain errors. Do not use it to make decisions about any patient or medication. Always follow your instructor, your supervising professional, and current official references and regulations.

VoTechWorks program approval and accreditation are still in progress. Credentials are issued only by the certifying bodies named in each program, after their own exams.

Nasogastric Tube Insertion, Feeding, and Medication Administration

A nasogastric (NG) tube is a flexible tube passed through the nostril, down the esophagus, and into the stomach. As an LPN, you will assist with or perform NG tube insertion, verify correct placement, administer enteral feedings, and give medications through the tube — all within your state-approved scope of practice and under the direction of a registered nurse or provider.

Indications and Tube Selection

NG tubes are used to deliver nutrition and medications when a patient cannot swallow safely, to decompress the stomach, or to remove gastric contents. Tubes are sized in French (Fr) units — the larger the number, the wider the tube. Common sizes for feeding range from 8 Fr to 12 Fr in adults. Larger-bore tubes (14–18 Fr) are used for gastric decompression or lavage.

Measuring Tube Length

Correct measurement prevents the tube from stopping short in the esophagus or advancing too far into the duodenum. Use the NEX method: measure from the Nose to the Earlobe, then from the earlobe to the Xiphoid process. Mark this point on the tube with a small piece of tape before insertion. This measurement gives you the approximate distance to the stomach.

Insertion Technique

1. Verify the provider order and confirm the patient's identity using two identifiers.

2. Explain the procedure; position the patient with the head of bed elevated at least 45 degrees.

3. Assess both nostrils; select the patent side.

4. Don gloves. Lubricate the tube tip with water-soluble lubricant.

5. Insert the tube through the nostril, aiming toward the back of the throat. Ask the patient to tuck their chin and swallow as the tube advances. Swallowing closes the trachea and guides the tube into the esophagus.

6. Advance the tube to the marked NEX length. Stop immediately if the patient coughs forcefully, becomes cyanotic, or cannot speak — these signs suggest tracheal placement.

7. Temporarily secure the tube with tape while you confirm placement.

On a simulation mannequin, the steps are identical. Practice a smooth, steady advance and clear communication at each checkpoint.

Placement Verification — The Critical Safety Step

Placement must be verified before anything is instilled through the tube. Instilling feeding or medication into a misplaced tube (particularly one in the airway) is a serious, potentially fatal error. Omitting this step is an automatic failure on your competency check.

Accepted bedside verification methods include:

Auscultation alone (the air-bolus method) is no longer considered a reliable verification method and should not be used as the sole check.

Document the pH reading, the aspirate characteristics, and the centimeter marking at the nostril in your clinical log.

Securing the Tube

After placement is confirmed, secure the tube to the nose with a commercial tube holder or hypoallergenic tape. Avoid pressure on the nasal ala that could cause skin breakdown. Loop the tube and secure it to the patient's gown or cheek to prevent tugging.

Administering an Enteral Tube Feeding

Before starting a feeding:

Gravity drip feeding: Fill the enteral feeding bag with the prescribed formula. Prime the tubing by allowing formula to flow to the tip, eliminating air. Flush the NG tube with water (typically 30 mL) before feeding. Hang the bag, open the roller clamp, and adjust the drip rate to deliver the prescribed volume over the prescribed time. Flush with water again after the feeding is complete.

Medication Administration Through an NG Tube

Not all medications can be crushed — extended-release, enteric-coated, and sublingual tablets must never be crushed. Verify each medication with a pharmacist or drug reference before crushing.

Procedure:

1. Flush the tube with water (typically 15–30 mL) before medication.

2. Administer each medication separately, dissolved in a small amount of water, to prevent incompatibility and tube occlusion.

3. Flush with water between each medication and again after the last one.

4. If the patient is receiving a continuous feeding, pause it as required for specific medications (for example, some medications require an empty stomach).

5. Clamp the tube for the appropriate dwell time if required by the medication.

Document the flush volumes as intake, the medication given, the time, and the patient's response.

Patient Safety Priorities

Key terms9

NEX measurementA method of estimating NG tube insertion length by measuring from the Nose to the Earlobe, then from the earlobe to the Xiphoid process, to approximate the distance from the nostril to the stomach.
French (Fr) sizeA unit used to measure the outer diameter of catheters and tubes; larger numbers indicate a wider tube.
Placement verificationConfirmation that the NG tube tip is in the stomach rather than the airway or esophagus, performed before any fluid or medication is instilled; required every time before use.
pH testingA bedside method of checking NG tube placement by testing the acidity of aspirated fluid with pH paper; gastric fluid is typically acidic (pH 1–5.5).
Gastric residual volume (GRV)The amount of fluid remaining in the stomach from a prior feeding, measured by aspiration before beginning the next feeding to assess gastric emptying and aspiration risk.
Enteral feedingDelivery of nutrition directly into the gastrointestinal tract through a tube, used when a patient cannot safely swallow adequate nutrition.
Aspiration (pulmonary)Inhalation of gastric contents or feeding formula into the lungs, a serious complication of tube feeding that can cause pneumonia or respiratory failure.
Priming the tubingFilling the feeding tube set with formula before connecting it to the patient, eliminating air to prevent air from being delivered into the stomach.
Tube occlusionBlockage of the NG tube, often caused by crushed medications that have not fully dissolved, formula residue, or inadequate flushing between administrations.

Worked examples4

1. The provider orders 240 mL of enteral formula to be infused by gravity over 30 minutes. Calculate the approximate drip rate in mL per minute to set.
  1. Identify the total volume: 240 mL.
  2. Identify the total time: 30 minutes.
  3. Divide volume by time: 240 mL ÷ 30 minutes = 8 mL per minute.
  4. Adjust the roller clamp on the enteral feeding tubing so that approximately 8 mL flows each minute.
Answer: 8 mL per minute.
2. You are preparing to measure NG tube insertion length using the NEX method. Nose to earlobe measures 14 cm. Earlobe to xiphoid process measures 24 cm. What length should you mark on the tube?
  1. Identify nose-to-earlobe distance: 14 cm.
  2. Identify earlobe-to-xiphoid distance: 24 cm.
  3. Add the two measurements: 14 cm + 24 cm = 38 cm.
  4. Mark the tube at 38 cm from the tip before insertion.
Answer: 38 cm from the tip of the tube.
3. After completing a tube feeding, the nurse's aide asks whether the 30 mL pre-feeding flush and the 30 mL post-feeding flush should be recorded as intake. The feeding volume was 240 mL. What is the total intake to document?
  1. Identify pre-feeding flush: 30 mL.
  2. Identify the feeding volume: 240 mL.
  3. Identify post-feeding flush: 30 mL.
  4. Add all volumes: 30 + 240 + 30 = 300 mL.
  5. All water and formula delivered through the tube counts as intake.
Answer: 300 mL total intake to document.
4. You aspirate gastric fluid from an NG tube and test it with pH paper. The color change indicates a pH of 3. Is this result consistent with correct gastric placement?
  1. Recall that gastric fluid is typically acidic, with a pH range of approximately 1 to 5.5.
  2. Compare the measured pH of 3 to the expected range: 3 falls within 1–5.5.
  3. Conclude that a pH of 3 is consistent with gastric placement.
Answer: Yes. A pH of 3 is within the acidic range expected for gastric fluid and supports correct placement.

The math in this lesson1

Learners compute a gravity feeding rate of 240 mL over 30 minutes as 8 mL per minute.
6.RP.3
In class: Watch a narrated demonstration of NG tube insertion, pausing to identify the critical safety checkpoint (placement verification before any instillation), and answer comprehension questions. · Insert an NG tube into a simulation mannequin, measure from nose to earlobe to xiphoid for tube length, secure the tube, and verify placement using aspiration and pH testing with pH paper. · Prime a simulated enteral feeding bag, set a gravity drip rate for a prescribed feeding volume, and administer a crushed simulated medication dissolved in water through the tube, flushing before and after.
Materials: NG tube insertion mannequin, NG tubes (various French sizes), 60 mL catheter-tip syringe, pH paper, enteral feeding bag and formula (simulated), tape and tube holder, crushed simulated medication, water, clinical log binder
Check: Placement verification step must be performed before any instillation—omission is an automatic failure; total competency checklist scored by instructor at 85% or higher for pass.

Practice check8

Answer each question, then check it. Nothing is recorded; this is your own practice.

Physiological Integrity: Reduction of Risk Potential
1. A nurse is preparing to insert an NG tube. Using the NEX method, the measurement from the nose to the earlobe is 12 cm, and from the earlobe to the xiphoid process is 26 cm. At what marking should the nurse mark the tube?
Safe and Effective Care Environment: Safety and Infection Control
2. Before initiating a tube feeding, the LPN aspirates fluid from the NG tube and tests it with pH paper. The result shows a pH of 7. What is the most appropriate next action?
Physiological Integrity: Reduction of Risk Potential
3. During NG tube insertion, the patient begins coughing forcefully and cannot speak. What should the nurse do immediately?
Safe and Effective Care Environment: Safety and Infection Control
4. Which method of NG tube placement verification is no longer considered reliable and should not be used as the sole confirmation method?
Physiological Integrity: Pharmacological and Parenteral Therapies
5. The nurse is about to give a crushed medication through an NG tube. The patient is also receiving a continuous tube feeding. What should the nurse do before administering the medication?
Physiological Integrity: Reduction of Risk Potential
6. To reduce the risk of aspiration during and after an enteral tube feeding, the nurse should position the patient at what minimum head-of-bed elevation?
Physiological Integrity: Pharmacological and Parenteral Therapies
7. A nurse is about to crush a tablet to give via NG tube. Which type of tablet should never be crushed?
Physiological Integrity: Reduction of Risk Potential
8. Before beginning a scheduled tube feeding, the nurse aspirates 280 mL of undigested formula from the patient's stomach. Based on this finding, what is the priority nursing action?
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