Nutrition, Tube Feeding and Medications by Tube

In depth

The one-page summary above is what the PDF prints. These sections go further.

Placement: why the x-ray, and the pH question

A blindly placed tube can curl in the esophagus or pass into the trachea, often without a cough in a drowsy client. Open RN asks for an x-ray right after insertion, before the tube is used, and then a mark at the nostril (or a recorded length at the abdomen) that is compared every 4 hours and before every feeding or medication. Watching the aspirate and the air-bolus test are no longer recommended because both can look normal with the tube in the wrong place.

Gastric aspirate is acidic: Open RN gives 5.5 or less in its enteral chapter and usually 5 or less in its medication chapter. Formula and acid-suppressing drugs raise the pH, so a higher value does not prove misplacement; when in doubt, get an x-ray. Merck notes that nasal tubes suit feeding for up to about 4 to 6 weeks; longer feeding, or a nose that cannot take a tube, is a reason for a gastrostomy or jejunostomy.

Residuals: how the advice changed

Residuals of 200 to 500 mL were once used to slow or stop feeding (Open RN). ASPEN safe-practice guidance, as Open RN reports it, now says a residual under 500 mL is not a reason to stop without other signs of intolerance, and SCCM/ASPEN critical care guidance and the American College of Gastroenterology advise against routine residual monitoring (as the 2021 Cochrane review reports). That review found no clear change in pneumonia when residuals were not monitored (one trial, 449 adults) and more vomiting without monitoring (two trials, 500 adults), all at very low certainty.

At the bedside the rule is symptoms first. Distention, nausea, vomiting, cramping or pain with a residual is intolerance: hold the feeding, keep the head up, assess the abdomen and report, since the provider may change the rate, formula or route or add a prokinetic. The ICU Nutrition and Refeeding page (ICU Basics) carries the trial data, prokinetic doses and refeeding syndrome.

Aspiration prevention

• Head of bed 30–45° during feeds; Merck adds 1–2 h upright after; Open RN keeps the head up at least 30° for 1 h after a bolus and 60 min after drugs.
• Use sedatives sparingly and review drugs that blunt cough and alertness.
• Check the tube mark and tolerance every 4 h.
• Brush teeth and tongue: fewer bacteria in secretions means less pneumonia if they are aspirated.
• A jejunal tube does not lower aspiration risk compared with a gastric tube (Merck); reflux and poor handling of secretions still cause aspiration.
• If bolus feeds cause nausea or vomiting, a continuous feed may be ordered instead (Merck).

Medications step by step

Open RN sequence: check each drug can be crushed (drug reference, pharmacist or the ISMP list); prepare each one in its own cup, crushed or opened and diluted in 5 to 10 mL of water; hold the feeding 1 to 2 hours before a drug that is incompatible with formula, 1 hour before if placement will be checked by pH, 30 minutes before an empty-stomach drug, and not at all for a drug that can be given with food; turn off suction; raise the head of the bed 30 to 45 degrees; confirm placement; flush at least 15 mL, give each drug with 15 mL between, finish with at least 15 mL; clamp a suction tube for 20 to 30 minutes; keep the head up 60 minutes; record the flush water as intake. Sterile water may be used for mixing and flushing in immunosuppressed or chronically ill clients.

Crushing an extended-release product dumps the whole dose at once, and the ISMP list (maintained by John F. Mitchell) gives the reason for each product it names. Capsules that are time-released are not opened. If no crushable or liquid form exists, the nurse holds the dose and asks the provider for another form or route rather than skipping it silently. Sorbitol in liquid drug preparations adds to diarrhea (Merck), which matters when a liquid substitute is chosen.

Diarrhea, clogs and intolerance

Formula intolerance occurs in up to about 20% of tube-fed clients and about half of critically ill ones (Merck); a continuous feed is used when bolus feeds are not tolerated. Look first at what can be changed: sorbitol and magnesium in liquid drugs, laxatives and softeners still ordered, antibiotics, rate increases, bolus delivery and hang time. Keep feeding while the cause is found; ask whether a stool test for C. difficile is wanted rather than giving an antidiarrheal first, and protect the perineal skin. A fiber-containing formula may help (Merck). Diluting the formula is not the answer: it cuts nutrition without treating the cause.

Clogs come from narrow tubes, thick formula, poorly crushed pills, mixing drugs and residual checks. Prevent them with scheduled water flushes (Merck: at least 30 mL every 4 h). To clear one, use warm water with gentle push-pull on a 60 mL syringe, then a pancreatic enzyme declogger per protocol (Open RN). Cranberry juice and carbonated drinks make clogs worse because their acid curdles formula protein. Do not force fluid in under high pressure.

Pump feeds often start at 20 to 30 mL/h and rise 10 to 20 mL/h every 4 to 8 hours to goal (Merck). Weight, electrolytes, glucose, magnesium and phosphate are checked daily in the first week; a severely undernourished client is at risk of refeeding syndrome when feeding starts.

Gastrostomy care and a tube that comes out

After PEG placement, some drainage is common for the first day or two and the skin heals in about 2 to 3 weeks (MedlinePlus). Clean the site 1 to 3 times a day with mild soap and water or sterile saline, rinse and dry it, avoid bulky dressings and gauze under the disc, and avoid ointments and powders unless ordered. Report leakage, red or irritated skin, a blocked tube, heavy bleeding, a hard swollen belly an hour after feeds, worse pain, new cough or breathlessness after feeds, or formula in the mouth.

The gastrocutaneous tract takes about 4 weeks to mature (Rosenberger 2011). Before that, a tube that falls out can leave the stomach leaking into the abdomen, and blind reinsertion has been followed by peritonitis and bleeding into the abdomen (Rosenberger 2011): cover the site, hold feeds and drugs, and call the provider at once for a new tube placed under imaging or endoscopy. With a mature tract, the opening can start to close, so the client is taught to secure the tube and get a new one placed right away (MedlinePlus).

NG decompression

Large double-lumen sump tubes decompress the stomach after surgery, in bowel obstruction or ileus, and after some poisonings (Open RN). The second (blue) lumen provides a continuous flow of air that lowers negative pressure and protects the stomach lining (Open RN); it is not used for irrigation and is never clamped. Suction is usually low intermittent; Open RN gives a low range of 0 to 80 mm Hg, starting at 40 to 60 and not exceeding 80.

Assess the nostril and tube security, the abdomen (suction off while listening) and the drainage each shift. A tube that stops draining while nausea and distention build is blocked, kinked, displaced or not on suction: check those, then irrigate as ordered. Bright red drainage after gastric surgery calls for vital signs and the provider. Days of gastric suction remove acid, potassium and chloride, so watch for metabolic alkalosis and low potassium.

Parenteral nutrition in more detail

TPN is for clients who cannot use the gut, such as paralytic ileus, bowel resection, short bowel or obstruction, and some cases of severe malnutrition, burns or hyperemesis (Open RN Fundamentals, Merck). When the gut works, enteral feeding is preferred: Merck notes better preservation of gut structure and function, lower cost and probably fewer infections. That is also why a client who cannot tolerate stomach feeds is often fed past the stomach rather than switched to TPN.

Solutions above 900 mOsm/L need a central line; peripheral PN is limited to 900 mOsm/L or less (Merck). The PN lumen carries nothing else, tubing is changed every 24 hours with the first bag of the day, and dressings are usually changed every 48 hours. Glucose is checked every 6 hours until stable (Merck), and insulin, when needed, is regular insulin added at about 1 unit per 10 g of dextrose. A sudden stop of concentrated dextrose can drop the glucose; brief hypoglycemia is treated with IV 50% dextrose and longer episodes with 5 to 10% dextrose for 24 hours (Merck).

Monitoring (Merck): weight, electrolytes, magnesium, phosphorus, BUN and creatinine daily for inpatients; liver tests at least weekly; triglycerides at least twice a week with lipid emulsions; intake and output continuously; no blood draws through the line while PN is running. Lipid emulsions run through a 1.2-micron filter and a lipid-only bag hangs no more than 12 hours (ICU Nutrition and Refeeding page, ASPEN 2021 and the lipid labels). At home, clients are taught not to use a bag that leaks, has changed color or contains particles, and to call for fever or a red, hard or painful catheter site (MedlinePlus).

Diets in more detail

Dumping syndrome follows surgery that speeds gastric emptying: gastrectomy, gastric bypass or sleeve, esophagectomy, fundoplication and vagotomy (NIDDK). Early dumping starts within 30 minutes of eating, with cramping, diarrhea, bloating, flushing, sweating, light-headedness and a fast heartbeat; late dumping comes 1 to 3 hours after a meal from low blood glucose, with shakiness, sweating and weakness. NIDDK advice: six small meals, liquids at least 30 minutes after meals, lying down for 30 minutes after eating, more protein, fiber and fat, complex rather than simple carbohydrates, no milk products, and pectin or guar gum to thicken food.

GERD and hiatal hernia share the same measures. NIDDK lists acidic foods, alcohol, chocolate, caffeine, high-fat foods, mint and spicy foods, and eating at least 3 hours before lying down. MedlinePlus adds smaller meals, staying upright 3 to 4 hours after the last meal, no clothes tight at the waist, bending at the knees, and avoiding aspirin and NSAIDs. Sources differ on the head-of-bed height: MedlinePlus says 4 to 6 inches on blocks or a wedge, noting that extra pillows under the head alone may not help; NIDDK says 6 to 8 inches with a wedge or pillows under the head and upper back.

Mucositis: NCI suggests soft, tender or blended foods served cool or at room temperature, ice chips, a straw, and avoiding citrus, tomatoes, spicy, salty, raw, crunchy foods and alcohol in drinks or mouthwash. Its patient page gives a rinse of 1/4 teaspoon baking soda and 1/8 teaspoon salt in 1 cup of warm water 3 or 4 times a day; the PDQ for professionals gives saline rinses every 4 to 6 hours, a soft toothbrush replaced regularly, and oral cryotherapy for bolus fluorouracil.

Nausea (NCI): five or six small meals, cold foods and bland starches such as toast, rice and crackers, sipping fluids through the day, ginger tea or ginger ale, avoiding greasy, sweet or spicy foods and strong smells, resting upright for about 30 minutes after eating, and wrist acupressure bands used with, not instead of, antiemetics. Supplements are checked with the team first because some interfere with cancer treatment. Chemotherapy diarrhea (NCI): small frequent low-fiber meals, plenty of fluids, foods high in sodium and potassium such as bananas, applesauce, soup and peeled boiled potatoes, and avoiding dairy, alcohol, caffeine, spicy and high-fat foods, beans, juice and sugar-free gum; report blood or mucus, fever, dizziness or weight loss. Severe diarrhea is 7 or more stools a day above the client’s usual number.

Dysphagia and oral suctioning

Swallowing problems can cause aspiration pneumonia, so the nurse sits the client upright in a chair or high Fowler position for meals, gives oral care first, offers only the ordered texture and liquid thickness, and stops the meal and reports if the client coughs or gags (Open RN Fundamentals). A speech-language pathologist evaluates swallowing. The IDDSI levels, liquid consistencies and NPO rules are on the Therapeutic Diets page.

Secretions pooling in the mouth that the client cannot clear are removed with a rigid Yankauer catheter: semi-Fowler position if conscious, side-lying facing the nurse if not; adult suction pressure no more than 150 mm Hg; each pass no longer than 10 to 15 seconds (Open RN).

Pyloric stenosis in more detail

Hypertrophic pyloric stenosis usually shows between 3 and 6 weeks of age and rarely after 12 weeks (Merck); MedlinePlus says vomiting often begins about 3 weeks. The infant vomits forcefully soon after feeding, keeps feeding eagerly, and looks well until dehydration sets in. A firm, movable olive-like mass of about 2 to 3 cm may be felt in the right upper abdomen, with peristaltic waves moving left to right. Vomiting stomach acid produces hypochloremic, hypokalemic metabolic alkalosis. Fluids and electrolytes are corrected before pyloromyotomy, and feeding usually resumes within a day, starting small and frequent.

Exam traps

• Air-bolus auscultation to check placement: always wrong.
• Stopping a feed for a residual alone under 500 mL: not current practice; symptoms decide.
• Mixing crushed drugs together or into formula: wrong; one at a time with flushes.
• Crushing an enteric-coated or extended-release product: wrong; ask for another form.
• Raising suction to continuous high for a tube that stops draining: wrong; check and irrigate as ordered.
• Pushing a tube or catheter blindly into a fresh PEG tract: wrong; cover and call.
• Stopping TPN abruptly or running it faster to catch up: both risk glucose swings.
• Fluids with meals after gastric surgery: wrong; between meals.